Benzenesulfonic acid, C10-13-alkyl derivs., sodium salts

Endpoint summary

Description of key information

Repeated dose toxicity studies were conducted through oral route in rats (Yoneyama 1976 a, Yoneyama 1972; Ito 1978 a, b, c; Oser 1965; study 1 - 6 in CSR) and mice (Yoneyama 1976 b, study 7 CSR), through dermal route in rats (Ito 1978 b) and through subcutaneous route in monkeys (Heywood 1978).

One oral study was performed with C10-13 LAS Na (Ito 1978a), two oral studies were performed with C10-13 LAS Mg (Ito 1978b and c) and four oral studies were performed with C10-14 LAS Na (Yoneyama 1976 a and b, Yoneyama 1972 and Oser 1965). The dermal study was performed with C10-13 LAS Mg (Ito 1978 d).

C10-13 LAS Mg is considered to be a similar substance as C10-13 LAS Na as both disassociate in vivo to form the identical LAS anion.

C10-14 LAS Na (source substance) has very similar composition to C10-13 LAS (target substance). Therefore read-across is considered to be acceptable.

The target and source substance only differ slightly in the C10 and C14 content. The substances present a similar potency of toxicological behaviour with respect to acute oral toxicity, with LD50 being 1080 mg/kg bw for the target substance and 900 mg/kg bw for the source substance. With respect to repeated dose endpoint, for the studies available on the source and target substances, the doses at which effects were observed were similar (after consideration of exposure route and dose spacing) as were the observed effects. 

For dietary exposures, LOAELs ranged from 300 to 500 for source and target substances, respectively. In both substances, the significant secondary effects observed at higher doses were similar. For the key studies available for the source substance, no significant effects in liver and kidneys were observed at the NOAELs of 40 mg/kg bw/day and 85 mg/kg bw/day. The consistency in the adverse effects seen in liver and kidneys in both studies supports the selection of 85 mg/kg bw/day as the appropriate NOAEL.

For the target substance, the supporting study by the same route resulted in a NOAEL of 150 mg/kg/day. Therefore, there is no evidence in the available data set that there are significant differences in potency between the source and target substances. In addition, use of data from the source substance represents an overall conservative approach in terms of the quantitative aspects of the repeated dose toxicity of these substances.

In conclusion, considering the entire dataset, the highest NOAEL for systemic toxicity below the lowest LOAEL (115 mg/kg bw/day from the 26 weeks dietary study with C10-14 LAS Na in rats, Yoneyama 1972, based on histopathological changes in liver and kidney) is 85 mg/kw bw/day from the 9 months drinking water study in rats with C10-14 LAS Na (Yoneyama 1976 a). In this drinking water study, the LOAEL was slightly higher at 145 mg/kg bw/day and based on liver and kidney enzyme changes. The consistency in the adverse effects seen in liver and kidneys in these studies (i.e. Yoneyama 1976 and Yoneyama 1972) supports the selection of 85 mg/kg bw/day as the appropriate NOAEL. Further, the selection of 85 mg/ kg bw/day as the appropriate NOAEL is also supported by the higher NOAEL of 150 mg/kg bw/day observed in the 26 weeks oral gavage study in rats with C10-13 LAS Mg (Ito 1978 b). Therefore, based on the entire data set, the point of departure taken forward for risk assessment purposes is the NOAEL of 85 mg/kg bw/day.

 

For dermal exposure, the systemic toxicity NOAEL was established at 5.0% (equivalent to 2500 mg/kg bw/day), based on no toxicologically relevant changes at any dose level in a sub-chronic 26 -weeks dermal repeated dose toxicity study with C10-13 LAS Mg in rats (Ito 1978 d).

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

sub-chronic toxicity: oral

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: read-across from a study predating current guidelines and GLP, but adequate for assessment.

Justification for type of information:

The repeated dose toxicity study of C10-13 LAS is based on read-across with C10-14 LAS. The read-across justification is presented in the assessment reports section. A cross-reference is made to that record.

Reason / purpose for cross-reference:

read-across source

Remarks:

study 1

Reason / purpose for cross-reference:

read-across source

Remarks:

study 2

Reason / purpose for cross-reference:

read-across source

Remarks:

study 6

Reason / purpose for cross-reference:

read-across source

Remarks:

study 7

Reason / purpose for cross-reference:

read-across: supporting information

Remarks:

read-across justification

Key result

Dose descriptor:

NOAEL

Remarks:

study 1

Effect level:

85 mg/kg bw/day (nominal)

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

clinical biochemistry

other: Liver and kidney enzymes

Remarks on result:

other: Based on the significant decreases in the activities of the glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na-KATPase in males and females at 145 mg/kg bw/day (0.2% drinking water)

Key result

Dose descriptor:

LOAEL

Remarks:

study 1

Effect level:

300 mg/kg bw/day (nominal)

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

clinical signs

haematology

histopathology: non-neoplastic

organ weights and organ / body weight ratios

water consumption and compound intake

other: Liver and kidney enzyme levels

Remarks on result:

other: Adverse effects were observed at all dose levels

Key result

Dose descriptor:

NOAEL

Remarks:

study 2

Effect level:

40 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical biochemistry

gross pathology

haematology

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Remarks on result:

other: Suppression of weight gain, increase in appendix weight, alternations in haematological and clinical biochemistry parameters and/or tissue damages to the large intestines, liver and kidneys in dose levels at >115 mg/kg bw/day (0.2% diet).

Dose descriptor:

NOAEL

Remarks:

study 6

Effect level:

50 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

organ weights and organ / body weight ratios

Remarks on result:

other: There was a significant increase in relative liver weights in females fed with 250 mg/kg bw/day.

Dose descriptor:

NOAEL

Remarks:

study 7 (drinking water study)

Effect level:

133 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

organ weights and organ / body weight ratios

other: Liver and kidney enzyme levels

Remarks on result:

other: This is based on alteration in liver and kidney weights and enzyme levels at higher tested dose level. As no other parameters (histopathology, clinical chemistry and haematological parameters) were evaluated in the study.

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

145 other: mg/kg bw day; study 1

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

145 other: mg/kg bw/day; study 1

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

115 other: mg/kg bw/day; study 2

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Critical effects observed:

yes

Lowest effective dose / conc.:

250 other: mg/kg bw/day; study 6

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Critical effects observed:

yes

Lowest effective dose / conc.:

380 other: mg/kg bw/day; study 7

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Critical effects observed:

yes

Lowest effective dose / conc.:

380 other: mg/kw bw/day; study 7

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Reference 2

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study is to determine the sub-acute toxicity of C10-13 sodium linear alkyl benzene sulfonate (LAS-Na) in CRJ-SD rats. LAS-Na was orally administered at 0 (distilled water), 125, 250 and 500 mg/kg bw to male and females rats for 29 and 30 days, respectively. General symptoms of toxicity and the body weights were recorded daily while the food consumption was measured twice a week. Urinalysis was also performed during the study. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters. After collection of blood samples, the animals were humanely euthanized, gross necropsy was performed and organs weights were determined.

GLP compliance:

no

Remarks:

(pre-dates GLP)

Limit test:

no

Species:

rat

Strain:

other: CRJ-SD rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Japan, Inc.
- Age at study initiation: 5 weeks
- Weight at study initiation: Not reported
- Fasting period before study: Not reported
- Housing: 3 male and 4 female animals per cage.
- Diet: Solid feed (CE-2, CLEA Japan, Inc.); ad libitum
- Water: Tap water; ad libitum
- Acclimation period: After 1 week pre-housing, the animals were used in the experiment.

ENVIRONMENTAL CONDITIONS
- Temperature: 23 ± 2°C
- Humidity: 55 ± 5%
- Air changes: Not reported
- Photoperiod: Not reported

EXPERIMENTAL START DATE: Not reported

Route of administration:

oral: gavage

Details on route of administration:

The test substance was administered orally through a metallic gastric sonde.

Vehicle:

other: Distilled water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: The test substance was suspended in distilled water prior to dosing.

- DOSE VOLUME: 5 mL/kg bw

- Concentration in vehicle: 0, 250, 500, and 1000 mg/mL respectively for administration of doses of 0, 125, 250 and 500 mg/kg bw.

Analytical verification of doses or concentrations:

no

Details on analytical verification of doses or concentrations:

29 days for males and 30 days for females

Duration of treatment / exposure:

29 days for males and 30 days for females

Frequency of treatment:

Once daily

Dose / conc.:

125 mg/kg bw/day (actual dose received)

Remarks:

In distilled water (corresponding to 250 mg/mL)

Dose / conc.:

250 mg/kg bw/day (actual dose received)

Remarks:

In distilled water (corresponding to 500 mg/mL)

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Remarks:

In distilled water (corresponding to 1000 mg/mL)

No. of animals per sex per dose:

Test group: 12 animals/sex/dose group
Control group: 15 male/group and 16 female/group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose levels for this study were selected based on the results of acute toxicity study conducted with LAS-Na in rats. 1/3 of the LD50 levels of LAS-Na, i.e. 500 mg/kg bw, was selected as the highest dose. The other two doses were set at common ratios of 2, whereby the medium and low doses were 250 (1/6 LD50) and 125 (1/12 LD50) mg/kg bw, respectively.

Positive control:

No

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily

BODY WEIGHT: Yes
- Time schedule for examinations: Daily

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption: Yes
- Time schedule for examinations: Twice/week

FOOD EFFICIENCY: Yes

WATER CONSUMPTION AND COMPOUND INTAKE: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: After 1 month, blood was collected was collected from the carotid artery using a cannula.
- Anesthetic used for blood collection: Yes, light ether anesthesia was used.
- Animals fasted: Not reported
- How many animals: All surviving animals
- Parameters: Haemoglobin, haematocrit, red and white blood cell count were measured using an auto-analyzer SMA-4A.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: After 1 month, blood was collected from each animal and centrifuged (at 3000 rpm for 15 minutes) to obtain the serum samples for analysis.
- Animals fasted: No
- How many animals: All surviving animals
- Parameters: s-GOT, s-GPT, alkaline phosphatase, total protein, albumin, glucose, cholesterol, bilirubin, creatinine, urea nitrogen, inorganic phosphates and ions (Na+, K+, Ca2+, Mg2+ and Cl-)

URINALYSIS: Yes
- Time schedule: Not reported
- Metabolism cages used for collection of urine: No
- Animals fasted: No
- How many animals: All surviving animals
- Parameters: pH, proteins, sugar, ketone bodies and occult blood

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

ORGAN WEIGHTS: The wet weight of liver, kidneys, spleen, adrenal glands, lungs, heart, thymus, reproductive organ, pituitary and the brain were measured. Based on this, the relative weights were calculated.

HISTOPATHOLOGY: No

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

At 500 mg/kg bw, animals exhibited the action of wetting the area around the mouth and nose, and rubbing it against the cage. Many animals exhibited diarrhea from the start of dosing as well as a suppressed state, several hours after dosing. Soft stool was observed in some animals dosed at 125 and 250 mg/kg bw, however, the animals showed recovery at low and mid doses.

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Male animals of all dose groups and female animals of high dose group (i.e. 500 mg/kg bw) exhibit body weight suppression.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Animals showed a dose dependent decline in the feed consumption.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Decreased feed efficacy was observed for male animals at 500 mg/kg bw.

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Effects at 125 mg/kg/bw: Decreased total proteins (only females), albumin (only females), Ca2+ levels (only males), and increased cholesterol (only males)
Effects at 250 mg/kg bw: Decreased s-GPT (both males and females), total proteins (only females), albumin (only females), Na+ (only males), K+ (only males), Ca2+ (both males and females), and Mg2+ (only males)
Effects at 500 mg/kg bw: Decreased s-GOT (only females), total proteins (only females), albumin (only females), glucose (only females), Ca2+ (both males and females), and increased alkaline phosphatase (only males) and urea nitrogen (only females).

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

The relative liver weight of female animals was significantly increased at 500 mg/kg bw (p<0.01). Apart from this, increase in relative weight of adrenal glands (p<0.05 for right side; p<0.01 for left side), testes (p<0.05) and brain (p<0.05) was also observed in male animals at 500 mg/kg bw. Decrease in the relative weight of liver (only females; at 125 mg/kg bw, p<0.05), right side kidney (only females; at 250 and 500 mg/kg bw, p<0.05), spleen (only males; at 500 mg/kg bw, p<0.05), heart (both males and females at 500 mg/kg bw, p<0.01; males at 250 mg/kg bw, p<0.05; females at 125 mg/kg bw, p<0.05) and thymus (only females; at 500 mg/kg bw, p<0.01) was also observed. Although, some significant effects were observed at the low and mid dose yet they were not dose-dependent.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

At 500 mg/kg bw, the animals showed hypertrophy in the stomach wall of the proventriculus, as if the process of inflammation and recovery had repeated over and over. Therefore, formation of new capillaries was observed on the peritoneal side. There were no additional changes relative to the control group although, events of hydronephrosis, bleeding plaques on the thymus and pneumonia were observed including the control group.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Dose descriptor:

NOAEL

Effect level:

125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

organ weights and organ / body weight ratios

Remarks on result:

other: Based on reduced body weight and changes in organ weight (without histopathological correlation), clinical chemistry. The LOAEL was 250 mg/kg bw/day.

Critical effects observed:

not specified

Table 1: Effect of LAS on average feed efficiency of rats after 1 month (po) exposure (Ito et al., 1978)

Sex	Doses	2 weeks			4 weeks
		Total intake (g)	Net gain (g)	Efficacy (%)	Total intake (g)	Net gain (g)	Efficacy (%)
Males	0	346.5	108.8	31.4	747.6	199.1	25.6
	125	322.7	97.5	30.2	692.3	183.2	25.4
	250	316.4	92.8	29.4	690.2	177.5	24.6
	500	284.2	76.5	27	633.5	152.4	22.7
Females	0	274.4	60.4	21.9	573.3	114.9	18.4
	125	236.6	53.7	22.6	513.1	105.4	19.5
	250	246.4	55.3	21.9	534.8	110.9	19.4
	500	231.7	49.6	21.4	486.5	97.8	18

Table 2: Effect of LAS on haematological parameters of rats after 1 month (po) exposure (Ito et al., 1978)

Sex	Doses	RBC (10^6/mm^3)	Hb (g/dL)	Ht (%)	WBC (10^3/mm^3)
Males	0	7.5 ± 0.11	16.5 ± 0.17	48.8 ± 0.63	16.5 ± 1.04
	125	7.4 ± 0.08	16.0 ± 0.13	47.4 ± 0.49	17.4 ± 1.12
	250	7.4 ± 0.17	15.9 ± 0.36	47.4 ± 1.13	17.8 ± 1.30
	500	7.5 ± 0.07	16.0 ± 0.12	48.1 ± 0.34	18.8 ± 1.41
Females	0	6.6 ± 0.15	15.2 ± 0.18	44.0 ± 0.65	12.1 ± 0.49
	125	6.6 ± 0.15	15.2 ± 0.15	44.4 ± 0.56	12.0 ± 0.87
	250	6.6 ± 0.11	15.2 ± 0.13	44.5 ± 0.51	13.5 ± 0.91
	500	6.8 ± 0.06	15.2 ± 0.10	44.2 ± 0.41	14.5 ± 1.31

Mean ± SE

* Significantly different from control (p<0.05)

** Significantly different from control (p<0.01)

Table 3a: Effect of LAS on biochemical parameters of rats after 1 month (po) exposure (Ito et al., 1978)

Sex	Dose (mg/kg)	sGOT	sGPT	ALP	TP	Alb	Glu	Chol
		mu/mL	mu/mL	mu/mL	mg%	mg%	mg%	mg%
Males	0	137.0± 5.4	44.5 ± 1.6	294.8 ± 11.6	5.4 ± 0.08	3.3 ± 0.05	228.7 ± 5.8	55.4 ± 1.27
	125	134.3 ± 8.4	39.5 ± 1.9	280.2 ± 17.5	5.1 ± 0.14	3.2 ± 0.08	228.9 ± 9.0	60.8* ± 2.38
	250	133.3 ± 7.3	39.3 ± 1.5*	311.8 ± 26.6	5.1 ± 0.27	3.1 ± 0.16	225.3 ± 11.5	54.5 ± 2.48
	500	145.4 ± 7.3	45.0 ± 2.1	374.0* ± 30.0	5.2 ± 0.07	3.3 ± 0.04	218.3 ± 3.5	53.4 ± 1.25
Females	0	130.3 ± 6.5	48.5 ± 1.1	184.9 ± 8.2	6.1 ± 0.08	3.8 ± 0.05	224.1 ± 5.7	67.7 ± 2.24
	125	141.0 ± 7.3	44.4 ± 1.1	205.2 ± 10.0	5.8** ± 0.7	3.7* ± 0.05	231.7 ± 8.4	63.9 ± 1.89
	250	134.5 ± 7.1	39.9 ± 0.8*	182.5 ± 11.5	5.7* ± 0.16	3.5** ± 0.09	216.2 ± 7.1	64.9 ± 2.81
	500	162.5* ± 10.7	44.1 ± 2.0	222.7 ± 17.9	5.7** ± 0.08	3.6** ± 0.05	207.8* ± 5.5	62.3 ± 2.30

Mean ± SE

* Significantly different from control (p<0.05)

** Significantly different from control (p<0.01)

Table 3b: Effect of LAS on biochemical parameters of rats after 1 month (po) exposure (Ito et al., 1978)

Sex	Dose (mg/kg)	T-Bili	Creat	BUN	InP	Na	K	Ca	Mg	Cl
		mg%	mg%	mg%	mg%	meg/L	meg/L	mg/dL	mg/dL	meg/L
Males	0	0.9 ± 0.03	0.5 ± 0.01	17.4 ± 0.99	6.8 ± 0.14	147.6 ± 1.7	5.0 ± 0.10	5.1 ± 0.07	2.5 ± 0.04	102.5 ± 0.62
	125	0.8 ± 0.04	0.5 ± 0.02	17.1 ± 1.32	6.8 ± 0.16	142.3 ± 2.0	4.8 ± 0.14	4.6* ± 0.14	2.5 ± 0.10	103.7 ± 0.65
	250	0.8 ± 0.04	0.4 ±0.03	17.0 ± 0.09	6.4 ± 0.26	135.8* ± 3.1	4.5** ± 0.11	4.6** ± 0.15	2.2** ± 0.05	104.6 ± 0.77
	500	0.9 ± 0.02	0.5 ± 0.02	19.3 ± 1.17	6.8 ± 0.10	141.5 ± 2.9	5.0 ± 0.17	4.8* ± 0.12	2.4 ± 0.06	104.4 ± 1.22
Females	0	0.9 ± 0.09	0.5 ± 0.02	17.9 ± 0.82	6.2 ± 0.14	143 ± 1.3	4.5 ± 0.09	5.2 ± 0.08	2.5 ± 0.07	105.4 ± 0.43
	125	0.8 ± 0.02	0.5 ± 0.01	17.9 ± 1.51	6.3 ± 0.23	143.4 ± 1.9	4.5 ± 0.08	5.0 ± 0.11	2.5 ± 0.07	106.8 ± 0.66
	250	0.8 ± 0.05	0.5 ± 0.01	18.7 ± 0.99	6.3 ± 0.22	145.3 ± 1.5	4.4 ± 0.15	4.9* ± 0.06	2.5 ± 0.06	106.8 ± 0.54
	500	0.9 ± 0.06	0.6 ± 0.02	24.0* ± 1.41	6.1 ± 0.21	142.6 ± 1.2	4.5 ± 0.08	4.9** ± 0.08	2.4 ± 50.0	106.6 ± 0.42

Mean ± SE

* Significantly different from control (p<0.05)

** Significantly different from control (p<0.01)

Table 4a: Effect of LAS on organ weight of rats after 1 month (po) exposure (Ito et al., 1978)

Sex

Dose (mg/kg)

Body weight (g)

Liver

Kidney

Spleen

Adrenal gland

Right

Left

Right

Left

wt (g)

%

wt (g)

%

wt (g)

%

wt (g)

%

wt (mg)

%

wt (mg)

%

Males

0

370.7± 6.0

14.60 ± 0.39

3.94 ± 0.08

1.38 ± 0.03

0.37 ± 0.01

1.38 ± 0.04

0.37 ± 0.01

0.70 ± 0.03

0.19 ± 0.01

25.6 ± 1.2

6.91 ± 0.32

25.8 ± 1.0

6.97 ± 0.26

125

355.1 ± 7.5

13.72±0.33

3.87 ± 0.06

1.36 ± 0.04

0.39 ± 0.01

1.33 ± 0.04

0.38 ± 0.01

0.68 ± 0.03

0.19 ± 0.01

24.4 ± 1.8

6.88 ± 0.48

25.3 ± 1.1

7.16 ± 0.37

250

349.8* ± 7.6

13.65 ± 0.42

3.90 ± 0.09

1.31 ± 0.03

0.38 ± 0.01

1.29 ± 0.03

0.37 ± 0.01

0.62 ± 0.03

0.18 ± 0.01

24.7 ± 1.4

7.06 ± 0.34

25.4 ± 1.5

7.24 ±0.35

500

324.4** ±9.0

13.37 ± 0.57

4.11 ± 0.11

1.21** ± 0.04

0.37 ± 0.01

1.20** ± 0.04

0.37 ± 0.01

0.53** ± 0.02

0.16* ± 0.01

26.2 ± 1.0

8.15* ± 0.40

28.5* ± 0.6

8.88** ± 0.36

Females

0

262.6± 8.0

10.84 ± 0.51

4.11 ± 0.08

1.09 ± 0.04

0.41 ± 0.01

1.08 ± 0.05

0.41 ± 0.2

0.55 ± 0.02

0.21 ± 0.01

34.0 ± 1.2

13.00 ± 0.38

35.8 ± 1.3

13.63 ± 0.30

125

258.0 ± 3.5

10.03 ± 0.22

3.89* ± 0.05

0.98* ± 0.03

0.38* ± 0.01

0.95* ± 0.02

0.37* ± 0.01

0.57 ± 0.02

0.22 ± 0.01

31.7 ± 1.1

12.27 ± 0.37

32.1 ± 1.5

12.43 ± 0.54

250

261.5 ± 4.5

10.56 ± 0.30

4.04 ± 0.08

1.00 ± 0.03

0.38* ± 0.01

0.96 ± 0.03

0.37* ± 0.01

0.56 ± 0.03

0.22 ± 0.01

31.0 ± 1.8

11.94 ± 0.84

33.4 ± 1.7

12.83 ± 0.76

500

249.7* ± 3.1

11.58 ± 0.21

4.64** ± 0.08

0.97** ± 0.02

0.39* ± 0.01

0.95* ± 0.02

0.38 ± 0.01

0.51 ± 0.01

0.21 ± 0.01

32.0 ± 1.9

12.79 ± 0.69

32.3 ± 2.0

12.89 ± 0.75

Mean ± SE

* Significantly different from control (p<0.05)

** Significantly different from control (p<0.01)

%: X10^-3

Table 4b: Effect of LAS on organ weights of rats after 1 month (po) exposure (Ito et al., 1978)

Sex

Dose (mg/kg)

Lung

Heart

Thymus

Testis/Ovarium

Pituitary

Brain

Right

Left

wt (g)

%

wt (g)

%

wt (g)

%

wt (mg)

%

wt (mg)

%

wt (mg)

%

wt (g)

%

Males

0

1.23± 0.02

0.33± 0.01

1.27 ± 0.05

0.34 ± 0.01

0.52 ± 0.02

0.14 ± 0.01

1.53 ± 0.03

0.41 ± 0.01

1.51 ± 0.03

0.41 ± 0.01

10.4 ± 0.4

2.81 ± 0.11

1.84 ± 0.03

0.50 ± 0.01

125

1.23 ± 0.03

0.35 ± 0.01

1.18 ± 0.03

0.33 ± 0.01

0.56 ± 0.05

0.16 ± 0.01

1.48 ± 0.03

0.42 ± 0.01

1.51 ± 0.03

0.43 ± 0.01

11.1 ± 1.1

3.14 ± 0.32

1.83 ± 0.03

0.52 ± 0.01

250

1.20 ± 0.03

0.35 ± 0.01

1.41 ± 0.03

0.33* ± 0.01

0.48 ± 0.02

0.14 ± 0.01

1.49 ± 0.04

0.43 ± 0.01

1.49 ± 0.03

0.43 ± 0.01

10.9 ± 0.7

3.10 ± 0.16

1.82 ± 0.02

0.52 ± 0.01

500

1.13* ± 0.03

0.35 ± 0.01

0.97** ± 0.03

0.30** ± 0.01

0.41** ± 0.03

0.13 ± 0.01

1.49 ± 0.04

0.46* ± 0.02

1.49 ± 0.04

0.46* ± 0.02

9.6 ± 0.4

2.99 ± 0.16

1.77* ± 0.02

0.55* ± 0.02

Females

0

1.07 ± 0.03

0.41 ± 0.01

0.96 ± 0.03

0.37 ± 0.01

0.59 ± 0.02

0.23 ± 0.01

44.8 ± 2.9

17.04 ± 0.95

47.8 ± 3.5

18.13 ± 1.07

11.8 ± 0.4

4.53 ± 0.18

1.80 ± 0.02

0.69 ± 0.02

125

1.10 ± 0.05

0.43 ± 0.02

0.88** ± 0.01

0.34* ± 0.01

0.54 ± 0.02

0.21 ± 0.01

46.2 ± 2.5

17.94 ± 1.04

43.7 ± 1.8

16.93 ± 0.64

12.3 ± 0.8

4.79 ± 0.30

1.78 ± 0.02

0.69 ± 0.01

250

1.11 ± 0.03

0.42 ± 0.01

0.92 ± 0.02

0.35 ± 0.01

0.55 ± 0.03

0.21 ± 0.01

46.5 ± 2.8

17.73 ± 0.94

47.6 ± 2.8

18.12 ± 0.91

11.8 ± 0.8

4.53 ± 0.30

1.76 ± 0.02

0.68 ± 0.01

500

1.01 ± 0.02

0.41 ± 0.01

0.79** ± 0.03

0.32** ±0.01

0.44** ± 0.04

0.18** ± 0.02

46.3 ± 3.5

18.51 ± 1.29

46.2 ± 2.7

18.44 ± 0.97

11.8 ± 0.9

4.71 ± 0.34

1.75* ± 0.01

0.70 ± 0.01

Mean ± SE

* Significantly different from control (p<0.05)

** Significantly different from control (p<0.01)

%: X10^-3

Conclusions:

Oral administration of C10-13 sodium linear alkylbenzene sulphonate (LAS-Na) to CRJ-SD rats at 0, 125, 250 and 500 mg/kg bw for 1 month resulted in a NOAEL of 250 mg/kg bw, based on reduced body weight, changes in organ weight (without histopathological correlation) and clinical chemistry at the mid and high doses. The LOAEL was 500 mg/kg bw.

Executive summary:

A short-term repeated dose toxicity study was conducted with C10-13 LAS, sodium salt in CRJ-SD rats. The test substance was administered via oral gavage to groups of male and female rats for 28 days at dose levels of 0, 125, 250 and 500 mg/kg/day. Clinical signs of toxicity and the body weights were recorded daily while the food consumption was measured twice a week. Urinalysis was also performed during the study. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters, following which the animals were humanely euthanized, gross necropsy was performed, the organs weights were determined and histopathological examination of the major organs were performed. Body weight gain was suppressed, some serum biochemical measures were different from the controls, and some organ weights were either decreased (spleen, heart, thymus) or increased (liver) at the high dose. No mortalities or histopathological abnormalities were observed. No adverse effects were up to 125 mg/kg bw/day mg/kg/day. Under the study conditions, the systemic toxicity NOAEL was determined to be 125 mg/kg/day based on reduced body weight, changes in organ weight (without histopathological correlation) and clinical chemistry at the mid and high doses (Ito, 1978a). 

Reference 3

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study is to determine the chronic toxicity (oral) of C10 - C13 linear alkylbenzene sulfonic acid magnesium salt (LAS-Mg) in CRJ-SD rats. Male and female rats were administered with 0, 75, 150 and 300 mg/kg bw/day of test substance for 26 weeks. General symptoms and body weight of animals were recorded on a daily-basis and food intake were recorded weekly. Urinalysis and haematological examinations were performed in week 5 and 13 of the study. At the end of study, urinalysis, haematological and serum biochemistry were also done. All the surviving animals were humanely euthanized after 26 weeks and organs (liver, kidneys, spleen, adrenal glands, lungs, heart, thymus, reproductive organ, pituitary, brain and thyroid) were collected for recording absolute and relative organ weights. All the collected organs (including stomach, duodenum, ileum, cecum, pancreas, bone marrow) were examined microscopically.

GLP compliance:

no

Remarks:

(pre-dates GLP)

Limit test:

no

Species:

rat

Strain:

other: CRJ-SD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Male and female rats were obtained from Charles River Laboratories Japan, Inc.
- Age at study initiation: Approximately 4 weeks
- Weight at study initiation: Not reported
- Fasting period before study: Not reported
- Housing: Animals were housed in cages with 2 animals/cage.
- Diet: Solid feed (CE-2, CLEA Japan, Inc.); ad libitum
- Water: Tap water; ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 1°C
- Humidity: 55 ± 5%
- Air changes: Not reported
- Photoperiod: Not reported

IN LIFE DATES: Not reported

Route of administration:

oral: gavage

Details on route of administration:

Test substance was forcibly administered using a metallic gastric sonde, once daily

Vehicle:

water

Remarks:

(distilled)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: Test substance solutions were prepared in distilled water to prepare required concentrations of 75, 150 and 300 mg/kg bw/day
- Storage conditions: Not reported
- DOSE VOLUME: 3 mL/kg bw for test substance as well as control group
- Preparation (%): 0, 2.5, 5 and 10% respectively for administration of doses of 0, 75, 150 and 300 mg/kg bw/day

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

26 weeks

Frequency of treatment:

Once daily for 26 weeks (excluding Sundays)

Dose / conc.:

75 mg/kg bw/day (actual dose received)

Dose / conc.:

150 mg/kg bw/day (actual dose received)

Dose / conc.:

300 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

20 animals/sex/dose group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were selected based on the subacute toxicity study of LAS-Mg, in which there was slight weight suppression of animals at 620 mg/kg bw/day (1/3 LD50). Hence, the high dose for this study was selected as 300 mg/kg (1/6 LD50). The lower doses were set at a common ratio of 2, with the medium dose being 150 mg/kg (1/12 LD50) and the low dose being 75 mg/kg (1/24 LD50).
- Rationale for animal assignment: Not reported
- Rationale for selecting satellite groups: No satellite groups were used in the study

Positive control:

Not included

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals were observed daily for general symptoms.

BODY WEIGHT: Yes
- Time schedule for examinations: All animals were weighed daily.

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule: Amount of food intake was measured once per week.

FOOD EFFICIENCY: Yes

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: During weeks 5, 11 and 26
- Anaesthetic used for blood collection: Yes. The animals were anesthetized with sodium pentobarbital
- Animals fasted: Not reported
- How many animals: During weeks 5 and 11, blood was collected from 10 animals/sex from the control group and 300 mg/kg bw/day group and in week 26, blood was collected from all animals.
- Parameters checked: Red blood cell count, white blood cell count, haemoglobin level and haematocrit level were measured, and white blood cell fractions were calculated by Giemsa-staining the blood smear samples.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At end of study i.e. 26 weeks
- Animals fasted: Not reported
- How many animals: All animals
- Parameters checked: s-GOT, s-GPT, alkaline phosphatase, total protein, albumin, glucose, cholesterol, bilirubin, creatinine, urea nitrogen, inorganic phosphates and Cl-, Na+, K+, Ca2+ and Mg2+

URINALYSIS: Yes
- Time schedule for collection of urine: During weeks 5, 11 and 26
- Metabolism cages used for collection of urine: No
- Animals fasted: Not reported
- How many animals: During weeks 5 and 11, urine was collected from 10 animals/sex from the control group and 300 mg/kg bw/day group and in week 26, urine was collected from all animals.
- Method: Lab sticks, Urobilistix and iktstix method (Semi-quantitative investigation)
- Parameters: pH, protein, glucose, ketone bodies, occult blood, urobilinogen and bilirubin

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
All animals were euthanized after blood sampling and organs were immediately collected.

TISSUE COLLECTED FOR ORGAN WEIGHTS AND HISTOPATHOLOGY: Liver, kidneys, spleen, adrenal glands, lungs, heart, thymus, reproductive organ, pituitary, brain and thyroid

HISTOPATHOLOGY: Above collected organs and stomach, duodenum, ileum, cecum, pancreas, bone marrow were fixed in 10% formalin, embedded in paraffin and underwent H&E staining before being examined under the microscope

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

There were wetting in the area surrounding animals’ mouths after dosing, and a few animals had abnormal airway sounds. Soft stools were seen in animals after one month, then recovered in few days.

Mortality:

mortality observed, treatment-related

Description (incidence):

One of the male animals in the 300 mg/kg bw/day dose group died (in week 21) from weakness due to significant weight loss involving diarrhea and loss of appetite.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

There was slight body weight suppression in the male animals of 300 mg/kg bw/day dose group.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

5 weeks interim analysis: There were decrease in segmented neutrophils and increase in lymphocytes in male animals in the 300 mg/kg bw/day dose group
13 weeks interim analysis: Significant decrease in basophils and haematocrit levels was observed for females and significant increase in segmented neutrophils and white blood cell count and significant decrease in lymphocytes were observed for males the 300 mg/kg bw/day dose group.
6 month analysis: Significant reduction in haematocrit levels for female animals in 300 mg/kg bw/day dose group was the only effect seen in haematological parameters.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

In 300 mg/kg bw/day dose groups: There was significant reduction in bilirubin, protein, albumin and calcium levels in male animals and in s-GPT, glucose, calcium and magnesium levels in female animals
In 150 mg/kg bw/day dose groups: There was significant reduction in s-GOT, s-GPT, alkaline phosphatase, protein, albumin, sodium and calcium levels in male animals and in chloride levels in female animals.
No effects were observed in 75 mg/kg bw/day treated animals.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

5 weeks interim analysis: No significant effects (on protein, occult blood, Urobilinogen and pH) were observed in treated animals as compare to control animals
13 weeks interim analysis: Male animals in the 300 mg/kg bw/day dose group showed + protein results. Others parameters (occult blood, Urobilinogen and pH) were comparable in control and treated animals.
26 weeks analysis: There were changes in protein levels in treated male animals as compare to control groups.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

In 300 mg/kg bw/day dose groups: Significant increased liver weights (absolute weight in females and relative weight in males), actual and relative thymus weights (males) and relative pituitary (males) weights were observed in treated animals as compare to control. Reduction in actual and relative heart weights (females), relative kidneys weights (males), and relative adrenal gland weights (females) were also observed in highest dose treated group.

In 150 mg/kg bw/day dose groups: Significant increased actual and relative thymus weights and actual pituitary weights were observed in male animals as compare to control. There was decreased relative heart weights in females and relative kidneys weights in males of this dose group.

In 75 mg/kg bw/day dose group: Significant dip in absolute heart weights and relative adrenal glands weights of females was seen in low dose group.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

- Yellow nodules was observed on liver for one male animal in the 75 mg/kg group.
- White spots were observed on adrenal glands for one female animal in the 75 mg/kg group.
- Bleeding spots in stomach were observed for two female animals in the 300 mg/kg group and one male animal in the 75 mg/kg group. Erosion was observed for one male animal in the 150 mg/kg group. Thickening of the proventriculus and yellow crust formation on the mucosal surface were observed for 11 male animals in the 300 mg/kg group and one male animal in the 150 mg/kg group.
- Stasis and diffuse emphysema in lungs were observed for one male animal in the control group.
- Oedema was observed in pituitary for one male animal in the 150 mg/kg group.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Control group:
- Hyperpyrexia of the bile duct was observed for one female, while steatosis was observed for another female animal.
- Renal tubular hyaline casts were observed for two each of male and female animals.
- Fibrosis of islets of Langerhans observed for two male animals.
- Stasis was observed for one male animal.
- Interstitial myocarditis was observed for two male animals, while epicarditis was observed for another animal.
300 mg/kg bw/day dose group:
- Interstitial small round cell infiltration was observed in kidney for one male animal and renal tubular calcification was observed for one female animal.
- Small round cell infiltration in the submucosal layer of stomach was observed for one male animal.

150 mg/kg bw/day dose group:
- Kupffer cell migration was observed for one male animal.
- Renal tubular hyaline casts were observed for one male animal, interstitial small round cell infiltration was seen for two male animals, renal tubular epithelial cell swelling was observed for one male animal and renal tubular calcification was observed for one female animal.
- Interstitial myocarditis was observed for two male animals.

75 mg/kg bw/day dose group:
- Focal necrosis was observed for one male animal, while Kupffer cell migration and sinusoidal dilation were observed for one female animal.
- Renal tubular hyaline casts were observed for three male animals, while interstitial small round cell infiltration was observed for two other male animals.
- Fibrosis of islets of Langerhans was observed for one male animal, and mild bleeding in the peripancreatic lymph glands were observed for another male animal.
-Interstitial pneumonia was observed for one female animal.
- Although interstitial myocarditis was observed for five male animals, one of them was a moderate change. Another animal experienced epicarditis.

Histopathological findings: neoplastic:

not examined

Dose descriptor:

NOAEL

Effect level:

150 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

haematology

histopathology: non-neoplastic

mortality

organ weights and organ / body weight ratios

urinalysis

Remarks on result:

other:

Remarks:

Based on body weight gain suppression, mortality, fluctuations in hematological and serum biochemistry, altered organ weights and histopathological alterations in kidney at 300 mg/kg bw/day.

Critical effects observed:

yes

Lowest effective dose / conc.:

300 mg/kg bw/day (actual dose received)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

Oral administration of C10-13 magnesium linear alkylbenzene sulphonate (LAS-Mg) to CRJ-SD rats at dose levels of 0, 75, 150 and 300 kg/kg bw/day for 26 weeks revealed no observed adverse effect level (NOAEL) of 150 mg/kg bw/day, based on weight suppression, mortality, fluctuations in haematological and serum biochemistry, altered organ weights and histopathological alterations in kidney at 300 mg/kg bw/day.

Executive summary:

A sub-chronic repeated dose toxicity study was conducted with C10-13 LAS, magnesium salt in CRJ-SD rats. The test substance was administered daily at dose levels of 0, 75, 150 and 300 mg/kg bw/day via oral gavage to groups of 20 animals/sex for 26 weeks. General symptoms and body weight of animals were recorded on a daily basis and food intake was recorded weekly. Urinalysis, haematological and clinical biochemistry examinations were performed during the in-life phase as well as at termination. Following necropsy of the surviving animals, gross pathological and histopathological examinations were performed. There was slight body weight suppression in the males at 300 mg/kg bw/day. Haematological findings revealed significant reduction in haematocrit levels for females at 300 mg/kg bw/day. There was significant reduction in bilirubin, protein, albumin and calcium levels in male animals and significant reduction in SGPT, glucose, calcium and magnesium levels in female animals at 300 mg/kg bw/day. Reduction in relative heart weight (females), kidney weight (males) and adrenal gland weight (females) were also observed in the highest dose group. In the kidneys, renal tubular epithelial cell swelling, hyaline casts and interstitial small round cell infiltration were observed at 300 mg/kg bw/day. There were no toxicologically significant effects at the lower doses. Under the study conditions, the systemic toxicity NOAEL was established at 150 mg/kg bw/day, based on reduction in body weight, fluctuations in haematological and serum biochemistry, altered organ weights and histopathological alterations in kidney at 300 mg/kg bw/day (Ito, 1978b).

Reference 4

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study is to determine the sub-acute toxicity of C10-13 Magnesium Linear Alkyl Benzene Sulfonate Salts (LAS-Mg) in CRJ-SD rats. LAS-Mg was orally administered at 0 (distilled water), 155, 310 and 620 mg/kg bw to male and females rats for 29 and 30 days, respectively. General symptoms of toxicity and the body weights were recorded daily while the food consumption was measured twice a week. Urinalysis was also performed during the study. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters. After collection of blood samples, the animals were humanely euthanized, and gross necropsy, organs weights and histopathology was performed.

GLP compliance:

no

Remarks:

(pre-dates GLP)

Limit test:

no

Species:

rat

Strain:

other: CRJ-SD rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Japan, Inc.
- Age at study initiation: 5 weeks
- Weight at study initiation: Not reported
- Fasting period before study: Not reported
- Housing: 3 male and 4 female animals per cage.
- Diet: Solid feed (CE-2, CLEA Japan, Inc.); ad libitum
- Water: Tap water; ad libitum
- Acclimation period: After 1 week pre-housing, the animals were used in the experiment.

ENVIRONMENTAL CONDITIONS
- Temperature: 23 ± 2°C
- Humidity: 55 ± 5%
- Air changes: Not reported
- Photoperiod: Not reported

EXPERIMENTAL START DATE: Not reported

Route of administration:

oral: gavage

Details on route of administration:

The test substance was administered orally through a metallic gastric sonde.

Vehicle:

other: Distilled water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: The test substance was suspended in distilled water prior to dosing.
- DOSE VOLUME: 5 mL/kg bw
- Concentration in vehicle: 0, 310, 620, and 1240 mg/mL respectively for administration of doses of 0, 155, 310 and 620 mg/kg bw.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

29 days for males and 30 days for females

Frequency of treatment:

Once daily

Dose / conc.:

155 mg/kg bw/day (actual dose received)

Remarks:

In distilled water (corresponding to 310 mg/mL)

Dose / conc.:

310 mg/kg bw/day (actual dose received)

Remarks:

In distilled water (corresponding to 620 mg/mL)

Dose / conc.:

620 mg/kg bw/day (actual dose received)

Remarks:

In distilled water (corresponding to 1240 mg/mL)

No. of animals per sex per dose:

Test group: 12 animals/sex/dose group
Control group: 15 male/group and 16 female/group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose levels for this study were selected based on the results of acute toxicity study conducted with LAS-Mg in rats. 1/3 of the LD50 levels of LAS-Mg, i.e. 620 mg/kg bw, was selected as the highest dose. The other two doses were set at common ratios of 2, whereby the medium and low doses were 310 (1/6 LD50) and 155 (1/12 LD50) mg/kg bw, respectively.

Positive control:

No

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily

BODY WEIGHT: Yes
- Time schedule for examinations: Daily

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption: Yes
- Time schedule for examinations: Twice/week

FOOD EFFICIENCY: Yes

WATER CONSUMPTION AND COMPOUND INTAKE: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: After 1 month, blood was collected was collected from the carotid artery using a cannula.
- Anesthetic used for blood collection: Yes, light ether anesthesia was used.
- Animals fasted: Not reported
- How many animals: All surviving animals
- Parameters: Haemoglobin, haematocrit, red and white blood cell count were measured using an auto-analyzer SMA-4A.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: After 1 month, blood was collected from each animal and centrifuged (at 3000 rpm for 15 minutes) to obtain the serum samples for analysis.
- Animals fasted: No
- How many animals: All surviving animals
- Parameters: s-GOT, s-GPT, alkaline phosphatase, total protein, albumin, glucose, cholesterol, bilirubin, creatinine, urea nitrogen, inorganic phosphates and ions (Na+, K+, Ca2+, Mg2+ and Cl-)

URINALYSIS: Yes
- Time schedule: Not reported
- Metabolism cages used for collection of urine: No
- Animals fasted: No
- How many animals: All surviving animals
- Parameters: pH, proteins, sugar, ketone bodies and occult blood

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

ORGAN WEIGHTS: The wet weight of liver, kidneys, spleen, adrenal glands, lungs, heart, thymus, reproductive organ, pituitary and the brain were measured. Based on this, the relative weights were calculated.

HISTOPATHOLOGY: Yes
Based on the results of the organ weight measurements, histopathology was performed only for the livers of male animals from the test and control groups. After Bouin fixing, paraffin embedding and H&E staining, the samples were examined under the microscope.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

At 620 mg/kg bw, animals exhibited the action of wetting the area around the mouth and nose, and rubbing it against the cage. Many animals exhibited diarrhea from the start of dosing as well as a suppressed state, several hours after dosing. Soft stool was observed in some animals dosed at 155 and 310 mg/kg bw, however, the animals showed recovery at low and mid doses.

Mortality:

mortality observed, treatment-related

Description (incidence):

One male animal (Day 6) and two female animals (Day 7 and 12, respectively) died from the high dose group (i.e. 620 mg/kg bw). In each case, the animal died from weakness after significant loss of body weight involving diarrhea and loss of appetite, and the necropsy revealed congestion of the gastric mucosa, intestinal relaxation, ascites retention, and it also involved lung congestion.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

At 620 mg/kg bw, males exhibited a body weight suppression on Day 2. Thereafter, the growth curve showed the same rate of increase as the control group, but the suppression was observed again after 3 weeks. In the end, body weight suppression was observed in animals (both males and females) belonging to the high dose group (i.e. 620 mg/kg bw).

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Animals showed a dose dependent decline in the feed consumption.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Decreased feed efficacy was observed for male animals at 620 mg/kg bw.

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Decreased haemoglobin and haematocrit level was observed in the male animals of high dose group (i.e. 620 mg/kg bw). No changes were observed in the RBC or WBC count.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

Decreased s-GOT (only males), K+ (only males) and Ca2+ levels (only females) was observed in the low dose group (i.e. 155 mg/kg bw). Increased s-GOT (both males and females) and alkaline phosphatase (only males), and decreased total proteins (only males), creatinine (only males) and Ca2+ levels (both males and females) was observed in the mid dose group (i.e. 310 mg/kg bw). Increased s-GOT, s-GPT and alkaline phosphatase (both males and females), and decreased total proteins (only females), albumin (only females), glucose (only females), cholesterol (only males) K+ (only males) and Ca2+ levels (both males and females) was observed in the high dose group (i.e. 620 mg/kg bw). The effects were not dose-dependent.

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

The relative liver weight of male and female animals was significantly increased at 620 mg/kg bw (p<0.01). Apart from this, increase in relative weight of testes (p<0.01) and brain (p<0.01) was also observed at 620 mg/kg bw. Decrease in the relative weight of kidney (both side at 310 mg/kg bw; right side at 155 mg/kg bw, p<0.05), adrenal gland (both sides at 155 and 310 mg/kg bw, p<0.05), heart (at 310 and 620 mg/kg bw, p<0.01) and thymus (at 620 mg/kg bw, p<0.05) was observed in the female animals. Although, some significant effects were observed at low and mid dose yet they were not dose-dependent.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

At 620 mg/kg bw, the animals showed hypertrophy in the stomach wall of the proventriculus, as if the process of inflammation and recovery had repeated over and over. Therefore, formation of new capillaries was observed on the peritoneal side. There were no additional changes relative to the control group although, events of hydronephrosis, bleeding plaques on the thymus and pneumonia were observed including the control group.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Focal necrosis and increased glycogen levels were observed in the liver of few animals belonging to mid and low dose groups, but these findings were common with the control group and also showed no dose-dependency.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Dose descriptor:

NOAEL

Effect level:

310 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

mortality

organ weights and organ / body weight ratios

Remarks on result:

other: Based on mortality, reduced body weight and changes in organ weight (without biochemical or histopathological correlation). The LOAEL was 620 mg/kg bw.

Critical effects observed:

not specified

Conclusions:

Oral administration of C10-13 magnesium linear alkylbenzene sulphonate (LAS-Mg) to CRJ-SD rats at 0, 155, 310 and 620 mg/kg bw for 1 month resulted in a NOAEL of 310 mg/kg bw, based on mortality, reduced body weight and changes in organ weight (without biochemical or histopathological correlation) at higher dose level. The LOAEL was 620 mg/kg bw.

Executive summary:

A sub-acute repeated dose toxicity study was conducted with C10-13 LAS, magnesium salt in CRJ-SD rats. The test substance was administered to groups of male and female rats via oral gavage at doses of 0, 155, 310 and 620 mg/kg bw/day for 29/30 days. Clinical signs of toxicity and the body weights were recorded daily while the food consumption was measured twice a week. Urinalysis was also performed during the study. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters, following which the animals were humanely euthanized, gross necropsy was performed and the organs weights were determined for the major organs. Based on the results of organ weight measurements, histopathology was performed only for the livers of male animals from the test and control groups. 1 male and 2 female animals died at the highest dose. The relative liver weight of male and female animals was significantly increased at 620 mg/kg bw/day. Apart from this, increase in relative testes weight and brain weight were also observed at this dose. Decrease in the relative heart weight (at 310 and 620 mg/kg bw/day) and thymus (at 620 mg/kg bw/day) was observed in the female animals. Although, some significant effects were observed at low and mid doses yet they were not dose-dependent. Histopathology revealed focal necrosis and increased glycogen levels in the liver of few animals belonging to the 155 and 310 mg/kg bw dose groups but these findings were comparable to the control group and were not dose-dependent. Under the study conditions, the systemic toxicity NOAEL was established at 310 mg/kg bw/day, based on mortality, reduced body weight and changes in organ weight (without biochemical or histopathological correlation) at the higher dose level (Ito, 1978c). 

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

85 mg/kg bw/day

Study duration:

subchronic

Species:

rat

System:

other: Hepatobiliary and urinary

Organ:

kidney

liver

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study is to determine the chronic toxicity (transdermal) of C10 - C13 linear alkylbenzene sulfonic acid magnesium salt (LAS-Mg) in CRJ-SD rats. Male and female rats were transdermally administered with 0 (water), 3% PEG, 0.5, 1.0 and 5.0% of test substance dissolved in 3% polyethyleneglycol (PEG, MW: 200) for 26 weeks. General symptoms and body weight of animals were recorded on a daily-basis and food intake were recorded weekly. Urinalysis and haematological examinations were performed in week 5 and 13 of the study. At the end of study, urinalysis, haematological and serum biochemistry were also done. All the surviving animals were humanely euthanized after 26 weeks and organs (liver, kidneys, spleen, adrenal glands, lungs, heart, thymus, reproductive organ, pituitary, brain and thyroid) were collected for recording absolute and relative organ weights. All the collected organs were examined under the microscope for histopthalogical changes.

GLP compliance:

no

Remarks:

(pre-dates GLP)

Limit test:

no

Species:

rat

Strain:

other: CRJ-SD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Male and female rats were obtained from Charles River Laboratories Japan, Inc.
- Age at study initiation: Approximately 4 weeks
- Weight at study initiation: Not reported
- Fasting period before study: Not reported
- Housing: Animals were housed in cages with 2 animals/cage.
- Diet: Solid feed (CE-2, CLEA Japan, Inc.); ad libitum
- Water: Tap water; ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 1°C
- Humidity: 55 ± 5%
- Air changes: Not reported
- Photoperiod: Not reported

IN LIFE DATES: Not reported

Type of coverage:

not specified

Vehicle:

other: 3% polyethyleneglycol (PEG, MW: 200)

Details on exposure:

TEST SITE
- Area of exposure: Shaved backs of animals
- % coverage: 3 x 3 cm2 area in the middle of the backside
- Type of wrap if used: Not reported
- Time intervals for shavings or clippings: Weekly

REMOVAL OF TEST SUBSTANCE
- Washing: Not reported
- Time after start of exposure: Not reported

TEST MATERIAL
- Amount applied: 0.1 mL
- Concentration: 0.5, 1.0 and 5.0% of C10-C13 LAS-Mg in 3% polyethyleneglycol

VEHICLE
- 3% polyethyleneglycol (PEG, MW: 200)

USE OF RESTRAINERS FOR PREVENTING INGESTION: No

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

26 weeks

Frequency of treatment:

Once daily for 26 weeks (excluding Sundays)

Dose / conc.:

0.5 other: %

Dose / conc.:

1 other: %

Dose / conc.:

5 other: %

No. of animals per sex per dose:

20 animals/sex/dose group

Control animals:

other: 2 Control animals groups were applied with either PEG or distilled water.

Details on study design:

- Dose selection rationale: Not reported
- Rationale for animal assignment: Not reported
- Rationale for selecting satellite groups: No satellite groups were used in the study

Positive control:

Not included

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals were observed daily for general symptoms.

DERMAL IRRITAION: Yes

BODY WEIGHT: Yes
- Time schedule for examinations: All animals were weighed daily.

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule: Amount of food intake was measured once per week.

FOOD EFFICIENCY: Yes

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: During weeks 5, 11 and 26
- Anaesthetic used for blood collection: Yes. The animals were anesthetized with sodium pentobarbital
- Animals fasted: Not reported
- How many animals: During weeks 5 and 11, blood was collected from 10 animals/sex from PEG group, control group and 5.0% group and in week 26, blood was collected from all animals.
- Parameters checked: Red blood cell count, white blood cell count, haemoglobin level and haematocrit level were measured, and white blood cell fractions were calculated by Giemsa-staining the blood smear samples.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At end of study i.e. 26 weeks
- Animals fasted: Not reported
- How many animals: All animals
- Parameters checked: s-GOT, s-GPT, alkaline phosphatase, total protein, albumin, glucose, cholesterol, bilirubin, creatinine, urea nitrogen, inorganic phosphates and Cl-, Na+, K+, Ca2+ and Mg2+

URINALYSIS: Yes
- Time schedule for collection of urine: During weeks 5, 11 and 26
- Metabolism cages used for collection of urine: No
- Animals fasted: Not reported
- How many animals: During weeks 5 and 11, urine was collected from 10 animals/sex from PEG group, control group and 5.0% group and in week 26, urine was collected from all animals.
- Method: Lab sticks, Urobilistix and iktstix method (Semi-quantitative investigation)
- Parameters: pH, protein, glucose, ketone bodies, occult blood, urobilinogen and bilirubin

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
All animals were euthanized after blood sampling and organs were immediately collected.

TISSUE COLLECTED FOR ORGAN WEIGHTS AND HISTOPATHOLOGY: Liver, kidneys, spleen, adrenal glands, lungs, heart, thymus, reproductive organ, pituitary, brain and thyroid

HISTOPATHOLOGY: Above collected organs and stomach, duodenum, ileum, cecum, pancreas, bone marrow and skin were fixed in 10% formalin, embedded in paraffin and underwent H&E staining before being examined under the microscope

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

In half of the animals of highest tested dose, mild redness of test site was observed one week after starting to apply it, but this disappeared after one week with desquamation. This did not occur again thereafter. Among female animals, all animals in the 5.0% group and one animal from the 1.0% group developed mild redness after one month since the start of study, but these went away after one week. After two, three months, half the animals in the 5.0% group exhibited mild redness, and it was seen sporadically thereafter.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One male animal from the control group (Week 16) and one male animal from the 5.0% group (Week 23) died during the study, but the cause remains unknown after finding no abnormalities through the necropsies.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Male animals in the 0.5% group exhibited mild weight suppression from Week 11, but this had recovered by Week 16. At the end of the experiment, slight weight suppression was observed in male animals from the 0.5% group.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

5 weeks interim analysis: There were significant increase in segmented neutrophils and significant decrease in white blood cell count for male animals in PEG group and increase in hematocrit levels in male animals in 5.0% dose group
13 weeks interim analysis: level: Significant increase in red blood cells and hemoglobin levels were observed in males of 5.0% dose group and increased white blood cell count was also observed for male and female animals in the PEG and 5.0% groups. In white blood cell fractions, decrease in eosinophils was observed for female animals in the 5.0% group.
6 month analysis: Significant decrease in white blood cell count were observed for female animals in the 5.0% group, as well as for both male and female animals in the 1.0% group. Significant increase in lymphocytes for male animals in the PEG group and significant decrease in monocytes for male animals in the 5.0 and 0.5% groups were also observed.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

PEG group: Significant decrease was observed in s-GOT levels for female animals and in sodium and s-GPT levels for all animals.
5.0% dose group: There was significant reduction in glucose in females, in calcium levels in males and sodium and s-GPT in all animals. Elevated levels of A/G ratio and cholesterol were also observed in females.
1.0% dose group: There is significant decrease in glucose in females and sodium levels in all animals and increase in urea nitrogen in females of this group.
0.5% dose group: There is significant decrease in sodium levels in all animals of this group and increase in urea nitrogen in females of this group.

Urinalysis findings:

no effects observed

Description (incidence and severity):

Similar levels of all tested parameters (protein, occult blood, Urobilinogen and pH) were observed in treated animals as compare to control animals in 13 as well as 26 weeks interim analysis.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

There were decrease in actual and relative liver weights of 0.5% (low) dose group. No dose dependency was observed for this effect.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

- Liver stasis was observed for one male animal in the 1.0% group, while blood spots and fading colour were observed for another male animal in the same group. Furthermore, white serpentine bulges were observed for three male animals each in the 5.0 and 0.5% groups, as well as in four male animals in 1.0% group and one male animal in the 0.5% group.
- Kidney oedema was observed for one female each in the control and 0.5% groups.
- Yellow discoloration was observed in pancreas for one male animal in the control group.
- Lungs stasis was observed for one male animal in the 1.0% group.
- Heart hypertrophy was observed for one male animal in the 1.0% group.
- Blood spots in thymus were observed for two male animals each in the control, PEG and 1.0% groups, as well as in four male animals in the 5.0 and 0.5% groups.
- Testicular atrophy was observed for one male in the 1.0% group, while ovarian oedema was observed for one female animal each in the control and 1.0% groups.
- Pituitary oedema was observed for one male animal in the 1.0% group.
- Stomach hematoma was observed in the cardia for one male animal in the 1.0% group, while an ulcer of 1 mm in diameter was observed for another male animal in the same group. Oedema was observed in the stomach for one male animal in the control group.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Control group:
- Sinusoid bleeding was observed for one male and one female animal each, while focal necrosis was observed for one female animal.
- Renal tubular hyaline casts were observed for seven male animals and one female animal, while interstitial small round cell infiltration and renal tubular epithelial cell swelling were observed for two male and one female animals
- Fibrosis of islets of Langerhans observed for one male animal
- Interstitial myocarditis was observed for one male and one female animal each.
PEG group:
- Sinusoid bleeding was observed for three male animals, focal necrosis was observed in one male animal and Kupffer cell migration was observed for one female animal
- Renal tubular hyaline casts were observed for five male animals and one female animal, while interstitial small round cell infiltration and renal tubular epithelial cell swelling were observed for one male and one female animal each
- Adrenal gland: A hemorrhagic foci was observed in the stratum corneum for one male animal.
- Fibrosis of islets of Langerhans observed for one male animal.
5.0% dose group:
- Sinusoid bleeding was observed for five male animals, while focal necrosis was observed for two male animals. Kupffer cell migration was observed for one female animal.
- Renal tubular hyaline casts were observed for three male and female animals each, while interstitial small round cell infiltration was observed for two male animals. Renal tubular calcification was observed for another male animal.
- Fibrosis of islets of Langerhans observed for one male animal.
- Interstitial myocarditis was observed for two male animals and one female animal.
1.0% dose group:
- Sinusoid bleeding was observed for five male animals, while focal necrosis was observed for another male animal.
- Renal tubular hyaline casts were observed for five male and one female animals, interstitial small round cell infiltration was observed for one male and one female animal each, and renal tubular calcification was observed for two female animals
- Fibrosis of islets of Langerhans observed for four male animals
- Interstitial myocarditis was observed for one male animal.
- Decline in sperm production was observed for one male animal.
0.5% dose group:
- Sinusoid bleeding was observed for four male animals and one female animal, while large lipid droplets were observed for one male animal. Kupffer cell migration was observed for one female animal.
- Renal tubular hyaline casts were observed for five male and two female animals, interstitial small round cell infiltration was observed for one male animal and another male animal exhibited renal tubular epithelial cell swelling. Furthermore, renal tubular calcification was observed for one female animal.
- Fibrosis of islets of Langerhans observed for three male animals.
- Interstitial myocarditis was observed for three male animals.

Histopathological findings: neoplastic:

not examined

Key result

Dose descriptor:

NOAEL

Effect level:

2 500 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No significant adverse effect was seen at any dose level.

Remarks on result:

other: Based on no growth, functional and morphological abnormalities, other than the localized effects at any tested dose levels.

Key result

Critical effects observed:

no

Conclusions:

Transdermal administration of C10-13 magnesium linear alkylbenzene sulphonate (LAS-Mg; purity: 96.9%) to CRJ-SD rats at dose levels of 0 (water), 3% PEG, 0.5, 1.0 and 5.0% of test substance dissolved in 3% polyethyleneglycol (PEG, MW: 200) for 26 weeks revealed no observed adverse effect level (NOAEL) of 5.0%, based no toxicologically relevant changes at any dose level.

Executive summary:

A sub-chronic 26-week repeated dose toxicity study was conducted in male and female CRJ-SD rats to evaluate the effects of C10-13 LAS, magnesium salt. The test substance was applied daily on the shaved backs of animals at dose levels of 0, 0.5, 1.0 and 5.0% dissolved in 3% polyethylene glycol (PEG) for 26 weeks with 20 animals/sex/dose group. General symptoms and body weight of animals were recorded on a daily-basis and food intake were recorded weekly. Urinalysis and haematological examinations were performed on Weeks 5 and 13 and also at termination, along with clinical biochemical examination. All the surviving animals were humanely euthanized after 26 weeks and organs were collected for recording absolute and relative weights and histopathological observation. There was slight reduction of body weight in males at 0.5% at the end of the study. No toxicologically significant changes were observed in food consumption, urinalysis, haematological and serum biochemical findings. No changes were seen in the organ weights and gross pathology of the collected organs. Histopathological findings were non-specific and had no dose-dependency. Under the study conditions, the systemic toxicity NOAEL was established at 5.0% (equivalent to 2500 mg/kg bw/day), based no toxicologically relevant changes at any dose level (Ito, 1978d). 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

2 500 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Oral 

Study 1 (C10-14LAS): 

A sub-chronic (9 months) repeated dose toxicity study was conducted with C10-14 LAS, sodium salt in male and female Wistar JCL rats. The test substance was administered at the following dose levels: through diet at 0, 0.6 and 1.8% (equivalent to 0, 300 and 900 mg/kg bw/day) to 8 animals/sex/dose and via drinking water at 0, 0.07 and 0.2% (equivalent to 0, 85 and 145 mg/kg bw/day to 9 animals/sex/dose. Rats at the 0.6 and 1.8% dose group exhibited severe weight loss so LAS administration via diet was stopped after 2 weeks. Clinical observations, water consumption, food consumption and body weights were recorded weekly. Terminal blood collection was done for estimation of haematological and clinical chemistry parameters. Gross findings were observed after euthanizing animals and organs were removed for organ weight measurements. No histopathology was performed. Body weight gain was reduced at the highest dose group only. Significant decreases in transaminase activity and renal Na,K-ATPase were seen at 145 mg/kg bw/day. No significant haematological or organ weight changes were noted. Based on significant decrease in the liver and renal enzyme levels at 145 mg/kg bw/day, the systemic toxicity NOAEL was established at 85 mg/kg bw/day (Yoneyama, 1976a).

 

Study 2 (C10-14LAS): 

A sub-chronic repeated dose toxicity study was conducted with C10-14 LAS, sodium salt in Wistar SLC rats. The test substance was administered to groups of 10 male and female rats/dose in the diet for 26 weeks at doses of 0, 40, 115, 340 and 1030 mg/kg/day. Clinical observations, water consumption, food consumption and body weights were recorded weekly. At the end of study, haematological, clinical chemistry and urine parameters were analysed. Gross pathological examinations were observed after necropsy and the major organs were subjected to histopathological examinations. Significant diarrhoea, suppressed growth, increased caecal weight and degeneration of renal tubes were observed in the highest dose group. Similar but less severe signs were seen in other doses with the exception of the lowest dose of 40 mg/kg/day, which showed no adverse effects related to exposure to the LAS. Under the study conditions, systemic toxicity NOAEL was determined to be 40 mg/kg/day, based on tissue damage in caecum, kidney and liver, haematological as well as clinical chemistry parameters changes at higher dose levels (Yoneyama, 1972)

  

Study 3 (C10-13LAS): 

A short-term repeated dose toxicity study was conducted with C10-13 LAS, sodium salt in CRJ-SD rats. The test substance was administered via oral gavage to groups of male and female rats for 28 days at dose levels of 0, 125, 250 and 500 mg/kg/day. Clinical signs of toxicity and the body weights were recorded daily while the food consumption was measured twice a week. Urinalysis was also performed during the study. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters, following which the animals were humanely euthanized, gross necropsy was performed, the organs weights were determined and histopathological examination of the major organs were performed. Body weight gain was suppressed, some serum biochemical measures were different from the controls, and some organ weights were either decreased (spleen, heart, thymus) or increased (liver) at the high dose. No mortalities or histopathological abnormalities were observed. No adverse effects were up to 125 mg/kg bw/day mg/kg/day. Under the study conditions, the systemic toxicity NOAEL was determined to be 125 mg/kg/day based on reduced body weight, changes in organ weight (without histopathological correlation) and clinical chemistry at the mid and high doses (Ito, 1978a). 

 

Study 4 (C10-13LAS): 

A sub-chronic repeated dose toxicity study was conducted with C10-13LAS, magnesium salt in CRJ-SD rats. The test substance was administered daily at dose levels of 0, 75, 150 and 300 mg/kg bw/day via oral gavage to groups of 20 animals/sex for 26 weeks. General symptoms and body weight of animals were recorded on a daily basis and food intake was recorded weekly. Urinalysis, haematological and clinical biochemistry examinations were performed during the in-life phase as well as at termination. Following necropsy of the surviving animals, gross pathological and histopathological examinations were performed. There was slight body weight suppression in the males at 300 mg/kg bw/day. Haematological findings revealed significant reduction in haematocrit levels for females at 300 mg/kg bw/day. There was significant reduction in bilirubin, protein, albumin and calcium levels in male animals and significant reduction in SGPT, glucose, calcium and magnesium levels in female animals at 300 mg/kg bw/day. Reduction in relative heart weight (females), kidney weight (males) and adrenal gland weight (females) were also observed in the highest dose group. In the kidneys, renal tubular epithelial cell swelling, hyaline casts and interstitial small round cell infiltration were observed at 300 mg/kg bw/day. There were no toxicologically significant effects at the lower doses. Under the study conditions, the systemic toxicity NOAEL was established at 150 mg/kg bw/day, based on reduction in body weight, fluctuations in haematological and serum biochemistry, altered organ weights and histopathological alterations in kidney at 300 mg/kg bw/day (Ito, 1978b).  

  

Study 5 (C10-13LAS): 

A sub-acute repeated dose toxicity study was conducted with C10-13LAS, magnesium salt in CRJ-SD rats. The test substance was administered to groups of male and female rats via oral gavage at doses of 0, 155, 310 and 620 mg/kg bw/day for 29/30 days. Clinical signs of toxicity and the body weights were recorded daily while the food consumption was measured twice a week. Urinalysis was also performed during the study. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters, following which the animals were humanely euthanized, gross necropsy was performed and the organs weights were determined for the major organs. Based on the results of organ weight measurements, histopathology was performed only for the livers of male animals from the test and control groups. 1 male and 2 female animals died at the highest dose. The relative liver weight of male and female animals was significantly increased at 620 mg/kg bw/day. Apart from this, increase in relative testes weight and brain weight were also observed at this dose. Decrease in the relative heart weight (at 310 and 620 mg/kg bw/day) and thymus (at 620 mg/kg bw/day) was observed in the female animals. Although, some significant effects were observed at low and mid doses yet they were not dose-dependent. Histopathology revealed focal necrosis and increased glycogen levels in the liver of few animals belonging to the 155 and 310 mg/kg bw dose groups but these findings were comparable to the control group and were not dose-dependent. Under the study conditions, the systemic toxicity NOAEL was established at 310 mg/kg bw/day, based on mortality, reduced body weight and changes in organ weight (without biochemical or histopathological correlation) at the higher dose level (Ito, 1978c).

  

Study 6 (C10-14LAS): 

A sub-chronic repeated dose dietary toxicity study was conducted with C10-14 LAS, sodium salt in Wistar FDRL rats. The test substance was administered to groups of 5 male and 5 female rats at dietary dose levels of 0, 50 and 250 mg/kg bw/day. Appearance, behaviour and overt signs of toxicity were observed daily. Food consumption and body weights of the rats of were recorded once weekly. During 6th and 12th week on test haematological, clinical chemistry and urine parameters were analysed. Following the 12-week clinical examinations, all surviving rats were sacrificed and gross pathological examination was performed. The major organs were weighed and histopathology was performed. No adverse effects on body weight gain, food consumption and behaviour were observed. The clinical data showed no abnormal variations in any of the dose groups. The relative organ weights and the histopathological evaluation did not show significant differences among the dose groups except for a significant liver weight increase in females of the highest dose group. Under the study conditions, the systemic toxicity NOAEL was established at 50 mg/kg bw/day based on increased relative liver weights in the females at 250 mg/kg bw/day (Oser, 1965).

 

Study 7 (C10-14 LAS)

The 9 months sub-chronic oral toxicity study of LAS was performed in SLC-ICR mice, focusing on the liver and kidneys.

4 weeks old male and female SLC-ICR mice(obtained from Shizuoka Agricultural Cooperative Association for Laboratory Animals) with body weight range 24 - 31 g (males), 20 - 25 g (females) were used in the study. 5 animals were housed in each cage and maintained under controlled environmental conditions (temperature: Average of25 ± 1°C, humidity:50 - 60%, and 12 hours light /12 hours dark). CE-2 diet (from CLEA Japan) and water were provided ad libitum. The animals were administered daily with the LAS at following dose levels for 9 months: Mixed in diet: 0 and 0.6% (equivalent to 0 and 780 mg/kg bw/day); 9 males in 0.6% fed group and 8 males in control group; 8 females in control as well as 0.6% fed group Dissolved in drinking water: 0, 0.07, 0.2 and 0.6 (equivalent to 0,133, 380 and 1140 mg/kg bw/day); 9 animals each in test substance treatment groups and 8 animals in control group Mice in 1.8% dose group of both feeding and drinking water study exhibited severe weight loss so LAS administration was stopped after 2 weeks. Clinical observations, water consumption, food consumption and body weights were recorded weekly. At the end of study, blood was collected for estimation of haematological and clinical chemistry parameters. Gross findings were obtained after euthanizing animals and organs were removed for organ weight measurements. Organ weights for brain, heart, lungs, liver, spleen, kidneys, adrenal gland, testes, uterus, and appendix were recorded. Liver and kidney enzymes were also analysed.

No mortality was observed throughout the study. There was significant inhibition of weight increase in both males and females of 0.6% dose group consuming LAS water compared to controls, while there was a significant increase in body weight compared to controls in males of 0.6% dose group fed with LAS in diet and 0.07% dose group consuming LAS water. Individual daily food consumption was higher in all treatment groups compared to controls. Water consumption was reduced in males of 0.6% dose group (drinking water study) and in females of 0.6% dose group (dietary study) and 0.2% dose group (drinking water study) and increased in males of 0.6% dose group (dietary study), 0.07 and 0.2% dose groups (drinking water study) and female of 0.07% dose groups (drinking water study). In males of 0.6% dose group (dietary study) and 0.07% dose group (drinking water study), the absolute liver weight was significantly increased, in males of 0.6% dose group (dietary study), 0.2 and 0.6 dose groups (drinking water study), the relative liver weight was significantly increased, and in 0.07% (drinking water) males the relative liver weight was increased. Relative lung, heart and kidney weights were also increased in male mice consuming 0.07% LAS water. In females, the relative liver weight was significantly increased in all treatment groups. Relative spleen, heart and kidney weights were also increased in female mice consuming 0.6% LAS water.

There was reductions in LDH activity in male mice of 0.6% group fed with LAS diet and GOT activity in male mice of 0.6% group consuming LAS water were significant. GOT activity in female mice of 0.2% group (drinking water study) was also significantly reduced. G6Pase was significantly reduced in males and female mice of 0.6% group consuming LAS water compared to controls, and also reduced in other treatment groups. No NOAEL can be identified for dietary study in mice, as only one dose level for LAS was fed to animals throughout the study. Administration of LAS to SLC-ICR mice by either test diets (0 and 0.6) or drinking water (0, 0.07, 0.2 and 0.6) for 9 months (focusing on the liver and kidneys) revealed an NOAEL of 0.07% (133 mg/kg bw/day in drinking water), based on observed adverse effects on organ weight and liver and kidney enzymes. Repeated administration of LAS impair renal and liver function. (Yoneyama, 1976b)

  

Dermal 

Study 1 (C10 -13LAS): 

A sub-chronic 26 -weeks repeated dose toxicity study was conducted in male and female CRJ-SD rats to evaluate the effects of C10-13LAS, magnesium salt. The test substance was applied daily on the shaved backs of animals at dose levels of 0, 0.5, 1.0 and 5.0% dissolved in 3% polyethylene glycol (PEG) for 26 weeks with 20 animals/sex/dose group. General symptoms and body weight of animals were recorded on a daily-basis and food intake were recorded weekly. Urinalysis and haematological examinations were performed on Weeks 5 and 13 and also at termination, along with clinical biochemical examination. All the surviving animals were humanely euthanized after 26 weeks and organs were collected for recording absolute and relative weights and histopathological observation. There was slight reduction of body weight in males at 0.5% at the end of the study. No toxicologically significant changes were observed in food consumption, urinalysis, haematological and serum biochemical findings. No changes were seen in the organ weights and gross pathology of the collected organs. Histopathological findings were non-specific and had no dose-dependency. Under the study conditions, the systemic toxicity NOAEL was established at 5.0% (equivalent to 2500 mg/kg bw/day), based no toxicologically relevant changes at any dose level (Ito, 1978d).

  

Other routes 

Study 1 (C10-13 LAS):

A 28-day repeated dose toxicity was conducted with C10-13LAS, sodium salt in Rhesus monkeys via oral and subcutaneous routes. The test substance was administered to the monkeys at doses of 0, 30, 150 and 300 mg/kg bw/day and at doses of 0, 0.1, 0.5 and 1.0 mg/kg bw/day for 28 days by simultaneous oral gavage and subcutaneous injection (into the dorsal aspect of the upper thorax) respectively. Clinical observations for any signs of toxicity, water consumption and food consumption were observed daily, and body weights was recorded once weekly. Ophthalmological, haematological, clinical chemistry and urine parameters were analysed before the start of the study and during the final week of dosing. Organ weights, gross pathological and histopathological examinations were performed on the major organs. No significant adverse effect was observed at food and water consumption of animals. All animals at the highest dose vomited on numerous occasions, usually within 3 h of being dosed. Vomiting was often associated with salivation. These effects are probably related to the inherent irritative effects of LAS rather than to its systemic toxicity. There was no further evidence of treatment-related effects among the ophthalmological, laboratory and other pathological investigations performed during this study. There was also a dose-related increase in the occurrence of chronic inflammatory cell infiltration (mainly fibroblasts) at the subcutaneous injection sites. Fibrosis of the injection sites was found among the entire test group, the incidence and severity being dose-related. Under the study conditions, a systemic toxicity NOAEL of 150 mg/kg bw/day (oral) and 0.5 mg/kg bw/day (sc) (Heywood, 1978). 

Justification for classification or non-classification

Repeated dose toxicity studies were conducted through oral route in rats, mice and monkeys, through dermal route in rats and through subcutaneous route in monkeys. These studies were conducted with the C10-13 LAS Na as well as with the read-across substance C10-14 LAS. No significant effects were observed at the sub-chronic NOAEL of 85 mg/kg bw/day in the 9 months oral gavage study (Yoneyama, 1976) with LAS. Slight to moderate histopathological lesions were observed at the LOAEL of 115 mg/kg bw/day (Yoneyama, 1972) which is above the guidance value recommended in the CLP guidance. Higher systemic NOAEL of 150 mg/kg bw/day were established in the other sub-chronic study (Ito, 1978b). Therefore, based on the results of the repeated dose studies, no classification is warranted for this endpoint according to EU CLP (1272/2008/EC) criteria.