Benzenesulfonic acid, 4-C10-13-sec-alkyl derivs., ammonium salts

Endpoint summary

Description of key information

Key Study:

270d NOAEL = 85 mg/kg bw/d (drinking water); LOAEL = 145 mg/kg bw/d (dietary); sub-chronic oral toxicity study: dietary and drinking water; Yoneyama et al., 1976 (read-across from benzenesulfonic acid, 4-C10-13-sec-alkyl derivs. - data from LAS-Na)

Supporting Studies:

180d NOAEL = 40 mg/kg bw/d (dietary); sub-chronic oral toxicity study: dietary; Yoneyama et al., 1972 (read-across from benzenesulfonic acid, 4-C10-13-sec-alkyl derivs. - data from LAS-Na)

28d NOAEL = 125 mg/kg bw/d (oral gavage); sub-acute oral toxicity study: gavage; Ito et al., 1978 (read-across from benzenesulfonic acid, 4-C10-13-sec-alkyl derivs. - data from LAS-Na)

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting 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

Remarks:

Acceptable study, followed scientific principles/standards, pre-dates GLP

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study was 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 o0, 125, 250 and 500 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.:

125 mg/kg bw/day (nominal)

Remarks:

In distilled water (corresponding to 250 mg/mL)

Dose / conc.:

250 mg/kg bw/day (nominal)

Remarks:

In distilled water (corresponding to 500 mg/mL)

Dose / conc.:

500 mg/kg bw/day (nominal)

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: Hemoglobin, hematocrit, 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:

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: Hemoglobin, hematocrit, 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

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

Details on results:

CLINICAL SIGNS: 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 was observed at any dose level.

BODY WEIGHT AND WEIGHT CHANGES: Body weight suppression was observed in animals (both males and females) belonging to the high dose group (i.e. 500 mg/kg bw).

FOOD CONSUMPTION AND COMPOUND INTAKE: Animals showed a dose dependent decline in the feed consumption. Decreased feed efficacy was observed for male animals at 500 mg/kg bw.

CLINICAL BIOCHEMISTRY: Few significant effects were observed in the biochemical parameters mainly at the mid and high dose level.

URINALYSIS: Results of urinalysis (pH, proteins, sugar, ketone bodies and occult blood) in the test animals were comparable to the control group.

ORGAN WEIGHT: 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 PATHOLOGY: 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.

Dose descriptor:

NOAEL

Effect level:

125 mg/kg bw/day (nominal)

Based on:

act. ingr.

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.

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 125 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 250 mg/kg bw.

Executive summary:

One month sub-acute oral toxicity study of sodium linear alkylbenzene sulphonate (LAS-Na) was performed in CRJ-SD rats. Five weeks old male and female CRJ-SD rats (obtained from Charles River Laboratories Japan, Inc.) were used in the study. 3 males and 4 females were housed in the cages maintained under controlled environmental conditions (temperature: 23 ± 2°C and humidity: 55 ± 5%). Solid feed (CE-2, CLEA Japan, Inc.) and tap water were provided ad libitum. The test substance was orally administered (via metallic gastric sonde) at 0 (distilled water), 125, 250 and 500 mg/kg bw (corresponding to 250, 500 and 1000 mg/mL) 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 the organs weights determined. No mortality was observed at any dose level. Significant body weight loss was observed at 500 mg/kg bw. 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. Few significant effects were observed in the biochemical parameters mainly at the mid and high dose level. Based on the results, 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 125 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 250 mg/kg bw.

Reference 2

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Reason / purpose for cross-reference:

read-across source

Dose descriptor:

NOAEL

Effect level:

125 mg/kg bw/day (nominal)

Based on:

act. ingr.

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

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 125 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 250 mg/kg bw.

Executive summary:

In a one-to-one read-across approach, the substance benzenesulfonic acid, 4-C10-13-sec-alkyl derivs. (data on LAS-Na as part of category approach) is considered appropriate for direct read-across (one-to-one) to benzenesulfonic acid, 4-C10-13-sec-alkyl derivs., ammonium salts (target substance) for the endpoint repeated dose toxicity (sub-chronic). In conclusion, 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 125 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 250 mg/kg bw..  A full justification for the read-across approach is presented in IUCLID Section 13.2.

Reference 3

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

30 May 1972 to 27 November 1972

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Acceptable study, followed scientific principles/standards, pre-dates GLP

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study was to determine the sub chronic toxicity of C10 - C14 linear alkylbenzene sulfonic acid sodium salt (LAS) in Wistar SLC rats. Male and female rats were maintained on diets of 0, 0.07, 0.2, 0.6 and 1.8% LAS (equivalent to 0, 40, 115, 340, 1030 mg/kg bw/day) for 26 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. Urinalysis was also performed 2 weeks before necropsy. All the surviving animals were humanely euthanized and gross necropsy, organs weights and histopathology was performed.

GLP compliance:

no

Remarks:

study pre-dates GLP

Limit test:

no

Species:

rat

Strain:

other: Wistar SLC

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Male and female were obtained from Shizuoka Agricultural Cooperative Association for Laboratory Animals
- Age at study initiation: Approximately 4 weeks
- Weight at study initiation: 80 - 90 g (male rats), 65 - 80 g (female rats)
- Fasting period before study: No
- Housing: 5 animals were housed per stainless steel cage.
- Diet: FII food (from Funabashi Farm); ad libitum
- Water: Tap water; ad libitum
- Acclimation period: Not reported

ENVIRONMENTAL CONDITIONS
- Temperature: 25 ± 1°C
- Humidity: 55 - 65%
- Air changes: Not reported
- Photoperiod: 12 hours dark /12 hours light

EXPERIMENTAL START DATE: May 30, 1972; EXPERIMENTAL END DATE: Nov. 27, 1972

Route of administration:

oral: feed

Details on route of administration:

C10 - C14 LAS was administered to animals by mixing 0.07, 0.2, 0.6 and 1.8% with pulverized FII feed, the powders were shaped into solid form before being freely provided for feeding along with tap water. As control, solid FII feed was provided to the animals.

Vehicle:

other: C10 - C14 LAS was administered in diet

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

26 weeks

Frequency of treatment:

Continuous in diet (ad libitum)

Dose / conc.:

40 mg/kg bw/day (nominal)

Remarks:

in diet (corresponding to 0.07% dose level)

Dose / conc.:

115 mg/kg bw/day (nominal)

Remarks:

in diet (corresponding to 0.2% dose level)

Dose / conc.:

340 mg/kg bw/day (nominal)

Remarks:

in diet (corresponding to 0.6% dose level)

Dose / conc.:

1 030 mg/kg bw/day (nominal)

Remarks:

in diet (corresponding to 1.8% dose level)

No. of animals per sex per dose:

10 animals/sex/dose group

Control animals:

yes, plain diet

Positive control:

No

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS: Yes

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Time schedule for examinations: Weekly

WATER CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule for examinations: Weekly

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: After 26 weeks, blood was collected from each animal prior to autopsy (for hemoglobin, hematocrit, red blood cells, white blood fractions and platelets) and during euthanasia (erythrocyte membrane resistance)
- Anesthetic used for blood collection: No
- Animals fasted: No
- How many animals: All surviving animals
- Parameters: Hemoglobin, hematocrit, red blood cells, white blood fractions and platelets, erythrocyte membrane resistance and blood coagulation time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: After 26 weeks, blood was collected from each animal after euthanasia.
- Animals fasted: No
- How many animals: All surviving animals
- Parameters: Total proteins, GOT activity, ALP activity, LAP activity, urea nitrogen, A/G ratio and bilirubin

URINALYSIS: Yes
- Time schedule: 2 weeks prior to autopsy, urine isolated and collected from waste was analyzed.
- Metabolism cages used for collection of urine: No
- Animals fasted: No
- How many animals: All surviving animals
- Parameters: Proteins, glucose, ketone bodies, occult blood, bilirubin and urobilinogen

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
Gross findings were obtained after euthanizing animals and macroscopic findings were observed.

ORGAN WEIGHTS: Brain, pituitary, thyroid, thymus, heart, lungs, liver, kidneys, spleen, adrenal gland, prostate, testes, uterus, ovaries and appendix

HISTOPATHOLOGY: Yes
Collected tissues (all tissues weighed and also stomach, large and small intestines, pancreas, epidiymis, skin and bones) were examined and subjected to microscopy through H.E., PAS and silver staining.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Severe diarrhea was observed in the high concentration group (1.8%).

Mortality:

mortality observed, treatment-related

Description (incidence):

In 24th week, 1 male animal from the 1.8% dose group died.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

There was significant inhibition of weight gain in both males and females of 1.8% dose group.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption was low in the 1.8% dose group relative to the control.

Food efficiency:

not examined

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

effects observed, treatment-related

Description (incidence and severity):

Water consumption was slightly low in animals of 1.8% dose group.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

In females of 1.8% dose group, a significant decrease in hematocrit and hemoglobin and significant increase in the erythrocyte membrane resistance was observed.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

There was dose dependent significant increase in ALP levels (at mid and high dose) and significant decrease in total protein (at high dose).

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):

1.8% dose group: Significant increase in relative weights of liver, suprarenal gland, testis, brain and caecum were observed in males and relative weights of heart, thyroid, liver, uterus, brain and caecum of females.
0.6% dose group: Significant increase in caecum relative weights in males and hypophysis in females.
0.2% dose group: Caecum relative weights were significantly increased in males and kidney relative weights were significantly decreased in females.

Gross pathological findings:

no effects observed

Description (incidence and severity):

No significant changes were observed in the animals.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The main findings were concerned with kidneys, liver and intestinal tract.
Kidney damage was seen at and above 0.2% dose groups. Mild hepatocyte changes were observed in animals of 1.8% dose group and microscopic changes in intestinal tract were observed in female rats of the 1.8 and 0.6% dose groups.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Details on results:

CLINICAL SIGNS:
- Severe diarrhea was observed in animals in the high concentration groups (1.8%) immediately after starting the study, and although the diarrhea gradually became milder after about 1 week, the animals did not recover fully by the end of the study. The animals moved slowly, and there lower abdomen was dirty.

MORTALITY: During week 24, 1 male animal from 1.8% dose group died.

BODY WEIGHT AND WEIGHT CHANGES: There was significant inhibition of weight gain in both males and females of 1.8% dose group, while the 0.6% dose groups showed slight but not significant trends to suppress weight gain.

FOOD CONSUMPTION AND COMPOUND INTAKE: Food consumption was low in the 1.8% dose group relative to the control.

WATER CONSUMPTION AND COMPOUND INTAKE: Water consumption was slightly low in the 1.8% dose group.

HAEMATOLOGY:
- A significant decrease in hematocrit and hemoglobin, a significant increase in the erythrocyte membrane resistance was observed among female animals in the 1.8% dose groups.
- Male and female rats in 1.8% dose group showed increase in white blood cell count, increase in neutrophil fraction out of the white blood cells and a decrease in lymphocytes.

CLINICAL BIOCHEMISTRY: There was dose dependent increase in ALP levels and decrease in total protein.

URINALYSIS: No effects were observed.

ORGAN WEIGHT:
- In highest concentration group (1.8%), significant increase in relative weights of liver, suprarenal gland, testis, brain and caecum were observed in males and relative weights of heart, thyroid, liver, uterus, brain and caecum of females.
In 0.6% dose group, there was significant increase in caecum relative weights in males and hypophysis in females.
In 0.2% dose group, caecum relative weights were significantly increased in males and kidney relative weights were significantly decreased in females.

GROSS PATHOLOGY
- The color of the liver in 2 males and 5 females from the 1.8% dose group was lighter than normal and seemed to have a yellowish white color mixed to it.
- In addition, lung tumors were seen in one female rat from the 0.2% dose group.

- Autopsy of one male rat from the LAS-1.8% dose group that died during the study had significant swelling of the abdomen. This was due to the swelling of the stomach and small intestines. The contents from the stomach to the first part of the jejunum was a blackish purple liquid. From thereon, the ileum was filled with a semi-transparent, viscous, gelatinous substance.

HISTOPATHOLOGY

The main findings were concerned with kidneys, liver and intestinal tract. The histological findings concerning the kidneys had differences in the extent and frequency of changes between the dosage and between male and female rats.

Kidneys:
- Chronic appearance of glomeruli indicating moderate level of atrophy (male/females of 0.6% treated groups)
- Glomeruli contributed to overall swelling through dilation of vessel lumen and interstitial swelling (significant in in male/female rats of 0.2 and 0.07% dose groups. They were not very significant in the 1.8 and 0.6%)
- The glomerular interstitum had thawn mildly but chronically (significant for male/female rats in 1.8 and 0.6% groups)
- Cloudy swelling/vacuolar degeneration of proximal renal tubular epithelial cells were seen (slightly significant in LAS treated groups).
- Small, yellowish brown blobs the size of nuclei were observed in the proximal renal tubular epithelial cells (significantly in male/females of 1.8% dose group)
- Blue lead color exhibited on the lumen of the Henle loop through H.E. staining, while substances giving a strong positive PAS response were forming layers in circular forms or were present in small pieces
- The renal tubule had collapsed (significantly in male/females of 1.8% dose group)
- Swelling of surrounding connective tissue was observed in the interstitium (significantly in males of LAS-0.2% dose group and both male and female rats of 0.6% dose group)

- Various changes to the kidneys as seen in 0.2% to 0.07% dose groups differ in their extent and frequency of incidence, but these changes were also seen in the control group, so they were not considered changes that lead to permanent damages like collapse of renal tubule or cyst formation.

Liver: Disappearance of basophilic substances in the hepatocytes and eosin thickening of hepatocytes were observed mildly in male and female rats of the 1.8% dose group.

Intestinal tract: Decrease in height of epithelial cells in the colonic mucosa and disappearance of vacuoles from goblet cells were observed mildly in female rats of the 1.8 and 0.6% dose groups.

Dose descriptor:

NOAEL

Effect level:

40 mg/kg bw/day (nominal)

Based on:

act. ingr.

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, alteration in hematological 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).

Critical effects observed:

yes

Lowest effective dose / conc.:

115 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

Administration of linear alkylbenzene sulfonic acid sodium salt (LAS) to Wistar SLC rats at dose levels of 0, 0.07, 0.2, 0.6 and 1.8% (equivalent to 0, 40, 115, 340, 1030 mg/kg bw/day) for 26 weeks revealed an NOAEL of 0.07% (40 mg/kg bw/day), based on tissue damage in caecum, kidney and liver, hematological and/or clinical chemistry parameters changes at higher dose levels (115 mg/kg bw/day and above).

Executive summary:

The 26 weeks sub-chronic oral toxicity study of linear alkylbenzene sulfonic acid sodium salt (LAS) was performed in Wistar SLC rats. Approximately 4 weeks old male and female Wistar SLC rats (obtained from Shizuoka Agricultural Cooperative Association for Laboratory Animals) with body weight range 80 - 90 g (males), 65 - 80 g (females) were used in the study. 5 animals were housed in each stainless steelcage and maintained under controlled environmental conditions (temperature: Average of25 ± 1°C, humidity:55 - 65%, and 12 hours light /12 hours dark).FII food (from Funabashi Farm)and tap water were provided ad libitum. The animals were administered daily with the LAS in diet at dose levels of 0, 0.07, 0.2, 0.6 and 1.8% (equivalent to 0,40, 115, 340, 1030 mg/kg bw/day) for 26 weeks. 10 animals/sex/dose group was taken in the study. 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 findings were obtained after euthanizing animals and organs were removed for organ weight measurements. Organ weights for brain, pituitary, thyroid, thymus, heart, lungs, liver, kidneys, spleen, adrenal gland, prostate, testes, uterus, ovaries and appendix were recorded. Liver and kidney enzymes were also analysed. Collected tissues were then examined and subjected to microscopy through H.E., PAS and silver staining.

1 male animal from the 1.8% dose group died. In the 1.8% dose groups, increase in relative weight of organs associated with diarrhea and significant suppression of weight gain has been remarked. There was also anemia and an increasing trend of white blood cell count, in addition to increased serum ALP activity, decrease in serum total protein and a very high level of tissue damage in the kidneys. In the 0.6% dose groups, there were mild suppression of weight gain, increased weight of appendix as well as fluctuations in serum ALP / total protein and tissue damage to the kidneys. In the 0.2% dose groups, there were increase in weight of appendix and histological abnormalities in a part of the kidneys. Various changes to the kidneys as seen in 0.2 to 0.07% dose groups differ in their extent and frequency of incidence, but these changes were also seen in the control group, so they were not considered changes that lead to permanent damages like collapse of renal tubule or cyst formation.

Administration of linear alkylbenzene sulfonic acid sodium salt (LAS) to Wistar SLC rats at dose levels of 0, 0.07, 0.2, 0.6 and 1.8% (equivalent to 0,40, 115, 340, 1030 mg/kg bw/day) for 26 weeks revealed an NOAEL of 0.07% (40 mg/kg bw/day), based on tissue damage in caecum, kidney and liver, hematological as well as clinical chemistry parameters changes at higher dose levels (115 mg/kg bw/day and above).

Reference 4

Endpoint:

sub-chronic toxicity: oral

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Reason / purpose for cross-reference:

read-across source

Dose descriptor:

NOAEL

Effect level:

40 mg/kg bw/day (nominal)

Based on:

act. ingr.

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, alteration in hematological 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).

Critical effects observed:

yes

Lowest effective dose / conc.:

115 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

Administration of linear alkylbenzene sulfonic acid sodium salt (LAS) to Wistar SLC rats at dose levels of 0, 0.07, 0.2, 0.6 and 1.8% (equivalent to 0, 40, 115, 340, 1030 mg/kg bw/day) for 26 weeks revealed an NOAEL of 0.07% (40 mg/kg bw/day), based on tissue damage in caecum, kidney and liver, hematological and/or clinical chemistry parameters changes at higher dose levels (115 mg/kg bw/day and above).

Executive summary:

In a one-to-one read-across approach, the substance benzenesulfonic acid, 4-C10-13-sec-alkyl derivs. (data on LAS-Na as part of category approach) is considered appropriate for direct read-across (one-to-one) to benzenesulfonic acid, 4-C10-13-sec-alkyl derivs., ammonium salts (target substance) for the endpoint repeated dose toxicity (sub-chronic). In conclusion, oral administration of linear alkylbenzene sulfonic acid sodium salt (LAS) to Wistar SLC rats at dose levels of 0, 0.07, 0.2, 0.6 and 1.8% (equivalent to 0, 40, 115, 340, 1030 mg/kg bw/day) for 26 weeks revealed an NOAEL of 0.07% (40 mg/kg bw/day), based on tissue damage in caecum, kidney and liver, hematological and/or clinical chemistry parameters changes at higher dose levels (115 mg/kg bw/day and above).  A full justification for the read-across approach is presented in IUCLID Section 13.2.

Reference 5

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Acceptable study, followed scientific principles/standards, pre-dates GLP

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study is to determine the sub chronic toxicity of LAS in Wistar JCL rats, focusing on the liver and kidneys. Male and female rats were maintained on either test diets (0, 0.6 and 1.8%) or drinking water (0, 0.07 0.2, 0.6 and 1.8%) for 9 months. 0.6 and 1.8% rats in drinking water study exhibited severe weight loss so LAS administration was stopped after 2 weeks. Mortality, clinical observations and body weights were recorded during the study. All the surviving animals were humanely euthanized at end of 9 months and gross necropsy, hematological, serum biochemical tests, enzyme tests on the liver and kidneys were performed and organs weights were measured. No histopathology was performed.

GLP compliance:

no

Remarks:

Study pre-dates GLP

Limit test:

no

Species:

rat

Strain:

other: Wistar JCL

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Male and female rats were obtained from Shizuoka Agricultural Cooperative Association for
Laboratory Animals
- Age at study initiation: 4-weeks old
- Weight at study initiation: 100 - 124 g (male rats), 82 - 100 g (female rats)
- Fasting period before study: No
- Housing: 5 animals were housed per cage.
- Diet: CE-2 food (from CLEA Japan); ad libitum
- Water: ad libitum
- Acclimation period: 1 week before the start of treatment

ENVIRONMENTAL CONDITIONS
- Temperature: 25 ± 1°C
- Humidity: 50 - 60%
- Air changes: Not reported
- Photoperiod: 12 hours dark /12 hours light

IN-LIFE DATES: Not reported

Route of administration:

other: Oral: Drinking water and feed

Details on route of administration:

LAS was administered to animals by mixing 0.6 and 1.8% in CE-2 food (CLEA Japan) and dissolving to 0.07 and 0.2% in drinking water.

Vehicle:

other: Test substance was administered either in diet or drinking water

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

9 months

Frequency of treatment:

Continuous in diet or drinking water (ad libitum)

Dose / conc.:

0.6 other: %

Remarks:

in diet

Dose / conc.:

1.8 other: %

Remarks:

in diet

Dose / conc.:

300 mg/kg bw/day (nominal)

Remarks:

in diet (corresponding to 0.6 % dose level)

Dose / conc.:

900 mg/kg bw/day (nominal)

Remarks:

in diet (corresponding to 1.8 & dose level)

Dose / conc.:

0.07 other: %

Remarks:

in drinking water

Dose / conc.:

0.2 other: %

Remarks:

in drinking water; 0.6 and 1.8% dose group (equivalent to 857.14 and 2571.43 mg/kg bw/day) were also included, however due to severe weight loss so LAS administration was stopped after 2 weeks.

No. of animals per sex per dose:

Feeding study (mixed in diet): 8 animals/sex/dose
Drinking water study: 9 animals/sex/dose

Control animals:

yes, concurrent vehicle

yes, plain diet

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS: Yes
- Time schedule: Weekly

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption: Yes
- Compound intake: Yes
- Time schedule for examinations: Weekly

FOOD EFFICIENCY: No

WATER CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule for examinations: Weekly

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: After 9 months, blood was collected from each animal after euthanizing.
- Anesthetic used for blood collection: No
- Animals fasted: Not specified
- How many animals: Not specified
- Parameters: White blood cells (WBC), red blood cells (RBC), Hemoglobin (Hgb), Hematocrit (Hct), mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC)

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: After 9 months, blood was collected from each animal after euthanizing.
- Animals fasted: Not specified
- How many animals: Not specified
- Parameters: Glutamate oxaloacetate transaminase (GOT), glutamate pyruvic transaminase (GPT), glucose content, urea nitrogen, total cholesterol, albumin, alkaline phosphatase (ALP) and cholinesterase

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

OTHER:
- Liver enzyme tests: Glucose 6-phosphatase (G6Pase), lactase dehydrogenase (LDH) and G6P-DH activity
- Kidney enzyme tests: G6Pase, LDH, GPT, GOT, ALP, acid phosphatase (ACP), Na, K-ATPase, and malate dehydrogenase (MDH)

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (However, no details in study report in mentioned)
Gross findings were obtained after euthanizing animals and organs were removed for organ weight measurements.

ORGAN WEIGHTS: Brain, heart, lungs, liver, spleen, kidneys, adrenal gland, testes, ovary, uterus, and appendix
HISTOPATHOLOGY: No

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Both female and male rats (drinking water study) exhibited a slight redness at the tips of their facial fur, and coarse fur all over their bodies.

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

There was significant decrease in body weight gain in males and females of 1.8% dose group fed with diet and in males of 0.2% dose group consuming LAS contained water.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

effects observed, treatment-related

Description (incidence and severity):

Increased water consumption was observed in males of 1.8% dose group fed with diet and 0.2% dose group consuming LAS contained water.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

A significant reduction in WBC was observed in 0.6% (diet) male rats and in MCV and MCH was observed in 1.8% (diet) female rats compared to controls.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

There were significant alteration in cholesterol [decrease; all doses, except female rats of 0.07% dose group (drinking water)], GPT [decreased; 0.6% dose group (diet) females)], GOT [decreased; 1.8% dose group (diet) males], albumin [decreased; 1.8% (diet) males] , ALP levels [Increase;male and female rats fed with 1.8% LAS-diet] and cholinesterase levels [Increase; in male rats fed with 1.8% LAS-diet].

Urinalysis findings:

not examined

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 males of 1.8% (diet), the absolute liver and testes weight was significantly decreased and the relative testes, liver and caecum weight was significantly increased and both absolute and relative spleen weight were also significantly reduced.
In females of 1.8% (diet), absolute and relative liver and caecum weight was significantly increased.
There was also significant decrease in absolute and relative heart weight in females of 0.6% (diet) and 0.07% (drinking water) dose groups.

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Liver enzyme tests:
Dietary study: G6Pase activity was reduced in 1.8% dose group males and females, G6P-DH activity was reduced in 0.6 and 1.8% dose group males and females, LDH activity was reduced in 0.6, 1.8% dose group. GOT and GPT activities were clearly reduced in males, while in females GPT activity was reduced only in 1.8% dose group and GOT activity was reduced in 1.8% dose group animals.
Drinking water study: LDH activity was reduced in 0.2% dose group males. GOT and GPT activities were clearly reduced in males and GOT activity was increased in 0.07 and 0.2% dose group animals.

Renal enzyme tests:
Dietary study: A significant difference was also observed in G6Pase activity. In females, G6Pase, Na, K-ATPase, and LDH activity were significantly reduced in 1.8% dose group (diet) animals
Drinking water study: In males, Na, K-ATPase activity was significantly reduced in 0.2% dose group. A significant difference was also observed in G6Pase activity.

Details on results:

CLINICAL SIGNS: Both female and male rats consuming LAS-containing water exhibited a slight redness at the tips of their facial fur, and coarse fur all over their bodies.

BODY WEIGHT AND WEIGHT CHANGES: There was significant decrease in body weight gain in male and females of 1.8% dose group fed with diet and in males of 0.2% dose group consuming LAS contained water.

WATER CONSUMPTION AND COMPOUND INTAKE: Increased water consumption was observed in males of 1.8% dose group fed with diet and 0.2% dose group consuming LAS contained water.

HAEMATOLOGICAL FINDINGS: A significant reduction in WBC was observed in 0.6% (diet) male rats compared to controls, and a significant reduction in MCV and MCH was observed in 1.8% (diet) female rats compared to controls.

CLINICAL BIOCHEMISTRY: Except female rats of 0.07% dose group (drinking water), a significant reduction or a reduction in cholesterol was observed in male and female rats of all dose groups compared to controls. GPT was significantly reduced in 0.6% dose group (diet) females, and reduced in females of other treatment groups. GOT was significantly reduced in 1.8% dose group (diet) males, and reduced in both females and males of other treatment groups. Albumin was significantly reduced in 1.8% (diet) males and reduced in males of 0.2% dose group (drinking water) and females of 1.8% dose group (diet). There was significant increase in ALP levels in male and female rats fed with 1.8% LAS-diet and cholinesterase levels in male rats fed with 1.8% LAS-diet.

ORGAN WEIGHT: In males of 1.8% (diet), the absolute liver and testes weight was significantly decreased and the relative testes and liver weight was significantly increased and both absolute and relative spleen weight were also significantly reduced. In females of 1.8% (diet), absolute and relative liver and caecum weight was significantly increased. There was also significant decrease in absolute and relative heart weight in females of 0.6% (diet) and 0.07% (drinking water) dose groups.

LIVER ENZYME TESTS: G6Pase activity was reduced in 1.8% dose group (diet) males and females, G6P-DH activity was reduced in 0.6 and 1.8% dose group (diet) males and females, where the percentage reduction was greater in 1.8% dose group (diet) animals. LDH activity was clearly reduced in 0.6, 1.8% dose group (diet), and 0.2% dose group (drinking water) males, but reduced in only 1.8% dose group (diet) females. GOT and GPT activities were clearly reduced in males, while in females GPT activity was reduced only in 1.8% dose group (diet) animals, and GOT activity was increased in 0.07 and 0.2% dose group (drinking water) animals but reduced in 1.8% dose group (diet) animals.

RENAL ENZYME TESTS: In males, Na, K-ATPase activity was significantly reduced in 0.2% dose group (drinking water) animals, and also reduced in other male treatment groups. A significant difference was also observed in G6Pase activity, where the reduction observed was associated with an increase in amount consumed. In females, G6Pase, Na, K-ATPase, and LDH activity were significantly reduced in 1.8% dose group (diet) animals, and G6Pase and LDH activity were also reduced in other treatment groups.

Dose descriptor:

LOAEL

Effect level:

300 mg/kg bw/day (nominal)

Based on:

act. ingr.

Remarks:

(dietary study)

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

clinical signs

haematology

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

Dose descriptor:

NOAEL

Effect level:

85 mg/kg bw/day (nominal)

Based on:

act. ingr.

Remarks:

drinking water study

Sex:

male/female

Basis for effect level:

clinical biochemistry

other: Liver and kidney enzyme levels

Remarks on result:

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

Critical effects observed:

yes

Lowest effective dose / conc.:

145 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Critical effects observed:

yes

Lowest effective dose / conc.:

145 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

Administration of LAS to Wistar JCL rats by test diets at dose levels of 0, 0.6 and 1.8% for 9 months (focusing on the liver and kidneys) revealed an LOAEL of 0.6% (300 mg/kg bw/day in diet), based on adverse effects at all dose levels.
Administration of LAS to Wistar JCL rats in drinking water at dose levels of 0, 0.07 and 0.2% for 9 months (focusing on the liver and kidneys) revealed an NOAEL of 0.07% (85 mg/kg bw/day in drinking water), based on significant decreases in the activities of glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na,K-ATPase in males and females at 145 mg/kg bw/day (0.2% drinking water).

Executive summary:

The 9 months sub-chronic oral toxicity study of LAS was performed in Wistar JCL rats, focusing on the liver and kidneys. 4 weeks old male and femaleWistar JCL rats(obtained from Shizuoka Agricultural Cooperative Association for Laboratory Animals) with body weight range100 - 124 g (males), 82 - 100 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-2diet (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, 0.6 and 1.8% (equivalent to 0, 300 and 900 mg/kg bw/day); 8 animals/sex/dose

- Dissolved in drinking water: 0, 0.07 and 0.2 % (equivalent to 0,85 and 145mg/kg bw/day); 9 animals/sex/dose

Rats in 0.6 and 1.8% dose group of 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 observed 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 histopathology was performed. No mortality was observed throughout the study. Both female and male rats consuming LAS-containing water exhibited a slight redness at the tips of their facial fur, and coarse fur over their bodies. There was significant decrease in body weight gain in male and females of 1.8% dose group fed with diet and in males of 0.2% dose group consuming LAS contained water.Increased water consumption was observed in males of 1.8% dose group fed with diet and 0.2% dose group consuming LAS contained water.

A significant reduction in WBC was observed in 0.6% (diet) male rats compared to controls, and a significant reduction in MCV and MCH was observed in 1.8% (diet) female rats compared to controls. A marked reduction in cholesterol was observed in male and female rats of all dose groups [except female rats of 0.07% dose group (drinking water)] compared to controls. This indicate hepatocyte damage. GPT was significantly reduced in 0.6% dose group (diet) females, and reduced in females of other treatment groups. GOT was significantly reduced in 1.8% dose group (diet) males, and reduced in both females and males of other treatment groups. Albumin was significantly reduced in 1.8% (diet) males and reduced in males of 0.2% dose group (drinking water) and females of 1.8% dose group (diet). There was significant increase in ALP levels in male and female rats fed with 1.8% LAS-diet and cholinesterase levels in male rats fed with 1.8% LAS-diet.

In males of 1.8% (diet), the absolute liver and testes weight was significantly decreased and the relative testes and liver weight was significantly increased and both absolute and relative spleen weight were also significantly reduced. In females of 1.8% (diet), absolute and relative liver and caecum weight was significantly increased. There was also significant decrease in absolute and relative heart weight in females of 0.6% (diet) and 0.07% (drinking water) dose groups.

Liver enzymes were markedly reduced in 1.8% fed rats, due to impaired liver function, indicates reduced enzyme synthesis and direct enzyme inhibition by LAS or its metabolites. Renal G6Pase and Na, K-ATPase activity decreased, indicating kidney impairment.

Administration of LAS to Wistar JCL rats bytest diets at dose levels of 0, 0.6 and 1.8% for 9 months (focusing on the liver and kidneys) revealed an LOAEL of 0.6% (300 mg/kg bw/day in diet), based on adverse effects at all dose levels.

Administration of LAS to Wistar JCL rats in drinking water at dose levels of 0, 0.07 and 0.2% for 9 months (focusing on the liver and kidneys) revealed an NOAEL of 0.07% (85 mg/kg bw/day in drinking water), based onsignificant decreases in the activities of glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na,K-ATPase in males and females at 145 mg/kg bw/day (0.2% drinking water).

Reference 6

Endpoint:

sub-chronic toxicity: oral

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Reason / purpose for cross-reference:

read-across source

Dose descriptor:

LOAEL

Effect level:

300 mg/kg bw/day (nominal)

Based on:

act. ingr.

Remarks:

dietary study

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

clinical signs

haematology

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

Dose descriptor:

NOAEL

Effect level:

85 mg/kg bw/day (nominal)

Based on:

act. ingr.

Remarks:

drinking water study

Sex:

male/female

Basis for effect level:

clinical biochemistry

other: Liver and kidney enzyme levels

Remarks on result:

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

Critical effects observed:

yes

Lowest effective dose / conc.:

145 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Critical effects observed:

yes

Lowest effective dose / conc.:

145 mg/kg bw/day (nominal)

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

Administration of LAS to Wistar JCL rats by test diets at dose levels of 0, 0.6 and 1.8% for 9 months (focusing on the liver and kidneys) revealed an LOAEL of 0.6% (300 mg/kg bw/day in diet), based on adverse effects at all dose levels.
Administration of LAS to Wistar JCL rats in drinking water at dose levels of 0, 0.07 and 0.2% for 9 months (focusing on the liver and kidneys) revealed an NOAEL of 0.07% (85 mg/kg bw/day in drinking water), based on significant decreases in the activities of glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na,K-ATPase in males and females at 145 mg/kg bw/day (0.2% drinking water).

Executive summary:

In a one-to-one read-across approach, the substance benzenesulfonic acid, 4-C10-13-sec-alkyl derivs. is considered appropriate for direct read-across (one-to-one) to benzenesulfonic acid, 4-C10-13-sec-alkyl derivs., ammonium salts (target substance) for the endpoint repeated dose toxicity (sub-chronic). In conclusion, administration of LAS to Wistar JCL rats in drinking water at dose levels of 0, 0.07 and 0.2% for 9 months (focusing on the liver and kidneys) revealed an NOAEL of 0.07% (85 mg/kg bw/day in drinking water), based on significant decreases in the activities of glutamate-oxalate transaminase and lactate dehydrogenase in males and significant decrease in renal Na,K-ATPase in males and females at 145 mg/kg bw/day (0.2% drinking water).  A full justification for the read-across approach is presented in IUCLID Section 13.2.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

85 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The database consists of a number of high quality studies that exceed the standard data requirements for the registered tonnage band. All studies (key and supporting) are of high quality.

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

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In the key study (Yoneyama et al. 1976), male and female rats were exposed to LAS in drinking water daily for 9 months. Test doses were 85, 145 and 430 mg/kg bw/d plus the control. Eight to nine animals of each sex were exposed per group. Body weight was suppressed in the highest dose group only. Significant decreases in transaminase activity and renal Na,K-ATPase were seen in the 145 mg/kg bw/d group. No significant haematological or organ weight changes were noted. Based on enzyme activity, the resultant LOAEL and NOAEL values were 145 and 85 mg/kg bw/day, respectively.

In a supporting study (Yoneyama et al. 1972), male and female rats were exposed to LAS in the diet daily for 6 months. The doses were 40, 115, 340 and 1030 mg/kg bw/d plus the control group. Significant diarrhea, suppressed growth, increased cecal 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 bw/d, which showed no adverse effects related to exposure to LAS. The resultant LOAEL and NOAEL values were 115 and 40 mg/kg bw/day, respectively.

In another supporting study (Ito et al. 1978), male and female rats were exposed to LAS via gavage daily for 28 days at three dose levels plus the control (0, 125, 250 and 500 mg/kg bw/d). 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) in either the male or female high dose groups. No mortalities or histopathological abnormalities were observed. The resultant LOAEL and NOAEL values were 250 and 125 mg/kg bw/day, respectively, based on serum-biochemical differences from the controls.

Justification for classification or non-classification

The substance does not meet the classification criteria in accordance with Regulation (EC) No 1272/2008 (CLP).