Reaction mass of m-cresol and 2-chloro-m-cresol and 6-chloro-m-cresol

Endpoint summary

Description of key information

No data on repeated dose toxicity for Preventol KMX are available. However, a read-across approach to 4-chloro-3-methylphenol was judged to be scientifically reliable (for details see Discussion below).
A reliable, GLP compliant 105 week oral toxicity feeding study with doses of 400, 2000 and 10000 ppm 4-chloro-3-methylphenol in the diet was performed according to OECD Guideline 453 with minor deviations. The NOAEL was found to be the mid dose of 2000 ppm corresponding to a NOAEL of 103 mg/kg bw/day for males and 134 mg/kg bw/day for females.
In a reliable GLP compliant OECD guideline 411 study 4-chloro-3-methylphenol was applied to wistar rats dermally on 5 days/week and 6 h/day under occlusive conditions at doses of 20, 100 and 500 mg/kg bw for 13 weeks. The NOAEL was the highest dose of 500 mg/kg bw/day.
Thus, according to the dangerous substance directive 67/548/EEC according to CLP 1272/2008/EC Preventol KMX has not to be classified for repeated dose toxicity.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: oral

Remarks:

combined repeated dose and carcinogenicity

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant OECD Guideline 453 study with minor deviation: Haematological examinations were performed on 10 instead of 20 rats/sex/group.

Qualifier:

according to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

yes

Remarks:

Haematological examinations were performed on 10 instead of 20 rats/sex/group.

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Bor:WISW (SPF Cpb)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: F. Winkelmann, Borchen, Germany
- Age at study initiation: approx. 5-6 weeks
- Weight at study initiation: 102-139 g (males), 94-125 g (females)

Route of administration:

oral: feed

Vehicle:

peanut oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 100% of nominal concentrations

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

24 month and 53 weeks (interim sacrifice group)

Frequency of treatment:

daily, free daily, free access to the diet containing the test substance.

Remarks:

Doses / Concentrations:
400, 2000, 10000 ppm
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
21.0, 103.1, 558.9 mg/kg bw/day (males)
Basis:
actual ingested

Remarks:

Doses / Concentrations:
27.7, 134.3, 743.5 mg/kg bw/day (females)
Basis:
actual ingested

No. of animals per sex per dose:

50 per sex and dose level (2-year group)
10 per sex and dose level (interim sacrifice group (53 weeks)

Control animals:

yes, concurrent no treatment

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS AND MORTALITY: Yes, at least twice daily (once daily on weekends and bank holidays)

DETAILED CLINICAL OBSERVATION: Yes, once weekly. Once weekly body surfaces and orifices, posture, general behaviour, respiration and excretory products were assessed.
BODY WEIGHT: Yes, before start of treatment, then once weekly and prior to necropsy

FOOD CONSUMPTION: Yes, week 1-13: once weekly, week 14-termination: once monthly

WATER CONSUMPTION: Yes, once monthly

OPHTHALMOSCOPIC EXAMINATION: Yes, 20 animals per sex per group: prior to start. Additional 20 animals per sex of the control and highest dose group: after 53 and 104 weeks

HAEMATOLOGY: Yes, at 10 rats/sex/group in 6 month intervals
- Parameters checked: Differential blood count using smears, haematocrit, haemoglobin concentration, erythrocyte count, leukocyte count, reticulocyte count, total platelet count, MCH, MCHC, MCV

CLINICAL CHEMISTRY:Yes, at 10 rats/sex/group in weeks 26/27, 51/52, 78/79, 103/104
- Parameters checked: Sodium, potassium, chloride, calcium, phosphate, glucose, total cholesterol, triglyceride, urea, total bilirubin, creatinine, total protein, albumin, creatine phosphokinase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase

URINALYSIS: Yes, at 10 rats/sex/group in 6 month intervals urine was collected during 16 hour intervals (overnight)
- Parameters checked: Semi-quantitative: pH, protein, glucose, ketone bodies, blood, bilirubin, sediment, urobilinogen
Quantitative: density, creatinine, protein, volume

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, all surviving animals at terminal sacrifice and on all animals dying spontaneously or sacrificed moribund during the study. At interim sacrifice 10 rats per sex and dose level.
ORGAN WEIGHTS: Yes, all surviving animals at interim and terminal sacrifice. The weight of following organs was assessed: Brain, heart, kidneys (in pairs), liver, ovaries (in pairs), testicles (in pairs), spleen.
HISTOPATHOLOGY: Yes, all surviving animals at terminal sacrifice and from 10 animals per sex and dose level at interim sacrifice. Histopathology was performed with following organs: Adrenals, aorta, bone, bone marrow (in femur and sternum), brain, caecum, cervix, colon, duodenum, tattooed ears, epididymides, Esophagus, eyes, eyelids, extraorbital lachrymal glands, femur with knee-joint, gross lesions, Harderian glands, head, heart, ileum, jejunum, kidneys, liver, lungs, lymph nodes (mandibular and mesenteric), mammary gland, optic nerve, ovaries, oviducts, pancreas, pituitary, prostate gland, rectum, salivary glands, sciatic nerve, seminal vesicle, muscle (thigh), skin, spinal cord, spleen, sternum, stomach, testicles, thymus, thyroid gland, tongue, trachea, ureters, urethra, urinary bladder, uterus, vagina, Zymbal glands

Statistics:

Arithmetic group means and standard deviations for body weight, food consumption, water-intake, blood and urine analysis and organ weights were determined. The values for the test collective were compared with the control collective by significance test (U-test) using the Mann-Whitney test or by Wilcoxon´s method on the significance level alpha = 5% and alpha = 1% (two-tailed).
Differences with p-values ≤ 0.01 and  0.05 were considered statistically significant.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

No treatment related death occured. Females of the mid and high dose in general poor condition.

Mortality:

mortality observed, treatment-related

Description (incidence):

No treatment related death occured. Females of the mid and high dose in general poor condition.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Delayed body weight development at high dose (males and females)

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):

Males of the high dose showed a higher water intake.

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Some parameters were affected.

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

mainly inceased kidney weights beginning in males at the mid dose.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

deformation of the kidneys in males of the high dose group.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Kidney effects in males of the high dose group.

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY: The number of animals of the main groups dying during the study period was slightly lower than that of controls in the case of males, and in the case of treated females slightly higher (after 400 and 10,000 ppm) or comparable to controls. The deaths were considered to be not treatment-related.
Females showed a dose-related increase in the frequency of poor general condition, which was statistically significant in the highest dose group. In addition from week 90 (approx.) females exhibited more frequently increased abdominal circumference. Females of the mid and high dose groups showed a significant decrease in the frequency of this finding compared to control animals.

BODY WEIGHT AND WEIGHT GAIN: Body weight development was not significantly affected up to 2000 ppm. At 10,000 ppm, both sexes showed delayed body weight gain.

FOOD CONSUMPTION: No treatment-related effects were seen.

WATER CONSUMPTION: Water intake of males at 10,000 ppm was higher than that of control animals. In all other groups and in females no effects on water consumption were seen.

OPHTHALMOSCOPIC EXAMINATION: No treatment-related effects were seen.

HAEMATOLOGY: No treatment-related effects were seen.

CLINICAL CHEMISTRY: Males and females of the highest dose group showed partly statistically significant reduced cholesterol and triglyceride concentrations at all investigation time points.
In the mid dose group males and females showed a tendency to lower potassium values.
Phosphate values of males and females at the high dose were statistically significant lower.
For the other electrolytes isolated statistically significant higher and lower values were recorded at different time points. These findings were considered to be not dose-related.

URINALYSIS: No treatment-related effects were seen.

ORGAN WEIGHTS: Interim sacrifice: No effects
Terminal sacrifice: Males of the mid and high dose group showed slightly increased kidney weights.
Females of the high dose group showed slightly increased kidney weights and increased relative ovary weights.

GROSS PATHOLOGY: Interim sacrifice: No treatment-related effects were noted.
Terminal sacrifice: 6 males of the high dose group showed a deformation of kidneys. There were no other treatment-related gross pathological findings.

HISTOPATHOLOGY: NON-NEOPLASTIC: Males of the high dose group showed a increased number of papillary necroses and cortical dilatation of the collecting tubules and cortical fibroses in the kidneys.

HISTOPATHOLOGY: NEOPLASTIC: Gross pathological and histopathological investigations gave no indication of carcinogenic effects of the test compound at doses up to and including 10,000 ppm.

Dose descriptor:

LOAEL

Effect level:

10 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on decreased bw gain in both sexes and kidney effects in males

Dose descriptor:

LOAEL

Effect level:

559 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: based on decreased bw gain and kidney effects in males

Dose descriptor:

LOAEL

Effect level:

744 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: based on decreased bw gain

Dose descriptor:

NOAEL

Effect level:

2 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No treatment related adverse effects were seen in animals of this treatment group.

Dose descriptor:

NOAEL

Effect level:

103 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: No treatment related adverse effects were seen in animals of this treatment group.

Dose descriptor:

NOAEL

Effect level:

134 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No treatment related adverse effects were seen in animals of this treatment group.

Critical effects observed:

not specified

Table 1: Summary of affected parameters upon clinical chemistry, haematology and urinalysis

	Dose group (ppm)
	0		400		2000		10,000			Dose-related
sex	male	female	male	female	male	female	male	female		male	female
parameter
Cholesterol	−	−	−	↓**	−	−	↓**	↓**		−	−
Triglycerides	−	−	−	↓*	↑**	↑*	↓*	↓**		−	−
Potassium	−	−	−	−	↓*	↓**	↓**	↓**		+	+
Phosphate	−	−	−	−	−	−	↓**	↓**		+	+
* p < 0.05; ** p < 0.01

Table 2: Summary of results

	Control		400 ppm		2000 ppm		10,000 ppm		Dose-response + / –
Sex	male^#	female^#	male^#	female^#	male^#	female^#	male^#	female^#	male	female
Parameter
Mortality	8/50	13/50	5/50	17/50	5/50	11/50	6/50	16/50	–	–
Body weight gain	−	↓	−	↓*	−	↓*	↓**	↓**	−	−
Organ weights (rel.)
brain	−	−	−	−	−	−	−	↑**	−	-
kidneys	−	−	−	−	↑*	−	↑**	↑*	+	+
ovaries	−	−	−	−	−	−	−	↑*	-	+
spleen	−	−	−	↑**	−	−	−	↑*	−	-
liver	−	−	−	↓*	−	−	−	−	−	-
Gross pathology Kidney deformation	0/42	0/37	0/45	0/33	0/45	0/39	6/44	0/34	+	−
Histopathology incidence non-neoplastic changes
Kidneys, papillary necrosis
unilateral	2/50 A	0/49	0/49	1/50	0/50	0/50	8/50	1/48	+
bilateral	0/50	0/49	0/49	0/50	0/50	0/50	1/50	1/48	+
truncated papilla	0/50 B	0/49	0/49	0/50	0/50	0/50	6/50*	0/48
collecting duct dilatation
unilateral	0/50 A	0/49	0/49	0/50	0/50	0/50	3/50	1/48	+	+
bilateral	0/50	0/49	0/49	0/50	0/50	0/50	0/50	1/48	-	+
Cortical fibrosis	0/50 C	0/49	0/49	0/50	0/50	0/50	7/50*	1/48	+	-
Epididymides, reduced spermatozoa	3/50	–	3/49	–	9/50	–	11*/50	–	–	–
Testicles, degenera­tion of seminiferous tubules	2/50	–	4/49	–	7/50	–	9/50	–	–	–
No. of animals with neoplastic changes	21/42	21/37	23/45	22/33	20/45	24/39	19/44	19/34	–	–
^#number of animals affected / total number of animals Significant trend: A, p < 0.05; B, p < 0.01; C, p < 0.001 Significantly different from controls: *p < 0.05; **p < 0.01

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

103 mg/kg bw/day

Study duration:

chronic

Species:

rat

Quality of whole database:

The NOAEL was found to be 103 mg/kg bw/day for males and 134 mg/kg bw/day for females. The database for this endpoint is deemed to be acceptable and sufficient for non-classification.

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:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP compliant OECD guideline 411 study, tested with the source substance CAS 59-50-7. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

EPA OPP 82-3 (Subchronic Dermal Toxicity 90 Days)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: SPF-bred Wistar rats, (Bor:WISW (SPF Cpb))

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann, Borchen, Germany
- Age at study initiation: 8-10 weeks
- Weight at study initiation: 196 - 213 g (males), 165 - 186 g (females)

Type of coverage:

occlusive

Vehicle:

polyethylene glycol

Remarks:

PEG 400

Details on exposure:

TEST SITE
- Area of exposure: About 5 x 5 cm² (left flank)
REMOVAL OF TEST SUBSTANCE
- Washing: Yes, wiping with polyethyleneglycol 400
TEST MATERIAL
- Amount applied: 1 mL/kg bw

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

5 days/week, 6 h/day

Remarks:

Doses / Concentrations:
20, 100, 500
Basis:
nominal per unit body weight

No. of animals per sex per dose:

10/sex/dose level

Control animals:

yes, concurrent no treatment

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS AND MORTALITY: Yes, twice daily (on weekends and holidays: once daily).

DETAILED CLINICAL OBSERVATION: Yes, once weekly the total body surface, orifices, posture, behaviour, respiration, excrements and all abnormal findings were examined.

BODY WEIGHT: Yes, before treatment, then once weekly and prior to necropsy.

FOOD CONSUMPTION: Yes, before treatment, then once weekly.

WATER CONSUMPTION: Yes, before treatment, then once weekly.

OPHTHALMOSCOPIC EXAMINATION: Yes, on all rats of the control and high dose group. Examinations were performed 3 days before start of treatment and on day 80 in week 12.

HAEMATOLOGY: Yes, all surviving animals in week 5 or 6 and at study termination.
Sampling was done after urine sampling.
Parameters: differential blood count, erythrocyte morphology, erythrocyte count, haemoglobin concentration, haematocrit, leukocyte count, MCH, MCHC, MCV, thromboplastin time, thrombocyte count, reticulocyte count

CLINICAL CHEMISTRY: Yes, all surviving animals in week 5 or 6 and at study termination.
Sampling was done after urine sampling.
Parameters: albumin, glucose, cholesterol, urea, total bilirubin, creatinine, total protein, triglycerides, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), glutamate dehydrogenase (GLDH), P, Cl, Ca,

URINALYSIS: Yes, all animals
Urines were collected in week 5 or 6 and at termination in week 13. Samples were collected over a 16-hour period (over night). No food was provided during this period.
Parameters (semi-quantitative): ketone body, pH value, blood, glucose, bilirubin, protein, urobilinogen, sediment
Parameters (quantitative): total protein, volume, density, protein, creatinine

OTHER: Thickness of skin folds were examined in all animals on treatment days 20 and 60.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, all surviving animals were sacrificed at study termination and a gross pathological examination was performed.

ORGAN WEIGHTS: Yes, from all animals sacrificed at termination.
Organs: brain, heart, testis (paired), liver, lung, spleen, kidneys (paired), adrenals (paired).

HISTOPATHOLOGY: Yes, from all animals of the control and highest dose group.
Organs: adrenals, aorta, femur with bone marrow, brain, colon, caecum, duodenum, ileum, jejunum, rectum, duodenum, epididymis, , eyes with nervi optici, femoral muscle heart, kidneys, liver, lungs, lymph nodes, mamma with skin, oesophagus, ovaries, pancreas, pituitary, prostate, salivary glands, seminal vesicles, nervus ischiadicus, skin of back (treated and normal skin), spleen, spinal cord, stomach, sternum with bone marrow, testicles, thymus, thyroid gland, trachea, urinary bladder, uterus, vagina, and all tissues with grossly apparent lesions.
In addition, liver, lungs and kidneys of all animals of the low and mid dose groups.

Statistics:

Arithmetic group means and standard deviations for bw, food consumption, water-intake, blood and urine analysis and organ weights were determined. The values for the test collective were compared with the control collective by significance test (U-test) using H.B. Mann and D.R. Whitney´s method, or by Wilcoxon´s method on the significance level alpha = 5% and alpha = 1% (two-tailed).
Differences with p-values ≤ 0.01 and ≤ 0.05 were considered statistically significant.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

all dose groups: females showed an unsettled behaviour the first 13 days of treatment. No mortalities occured in any dose group.

Dermal irritation:

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

all dose groups: females showed an unsettled behaviour the first 13 days of treatment. No mortalities occured in any dose group.

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

high dose group: Two males and one female had a pale kidney. However, without histopathological correlates.

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY: During the first 10 treatment days, all females of all dose groups showed an unsettled behaviour (increased motility with bounding, throwing down, jumping off, running around, biting into cage cover and occlusion). These symptoms decreased from day 11 to 13. From day 14 onwards females behaved like the males. No other signs were noted. No mortalities occurred.

BODY WEIGHT AND WEIGHT GAIN: Body weight gain of all males and females treated with the test substance was comparable to the body weight gain of control animals. The reduced mean body weights of all females of all dose and control groups in week 10 were considered to be not treatment-related.

CLINICAL CHEMISTRY: Males, high dose group: In week 6 the triglyceride values were significant lower compared to control animals. Since the differences were small, only present in one sex and in week 6, this effect was considered to be of no toxicological relevance. In week 13 the protein concentration was significant lower compared to control animals. Since the mean value was within the range of historical controls and only slightly different from control animals, this effect was considered to be of no toxicological relevance.
Males and females of the mid and high dose group:
In week 6, Ca-values of the females, in week 13, Ca-values of males and females were significant lower compared to control animals. This was considered to be not toxicological relevant.
No other effects were found.

GROSS PATHOLOGY: Control group: Two males had smaller testis. This was considered to be of no toxicological relevance.
low dose group: Epididymis of one male showed several yellow areas, which were considered to be of no toxicological relevance.
High dose group: 2 males and one female had a pale kidney.

OTHER FINDINGS: Examination of the skin thickness revealed no significant differences between the control and test substance groups.

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No treatment related adverse effects were seen in any dose group.

Critical effects observed:

not specified

Table 1. Results of clinical chemistry, haematology and urinalysis
Parameter changed	Unit	Weeks after treatment	Controls	20 mg/kg bw	100 mg/kg bw	500 mg/kg bw	Dose-response +/–
Males
Triglycerides	mmol/L	6	1.04	0.90	1.09	0.76**	–
		13	1.00	0.96	0.96	0.88	–
Total protein	g/L	6	61.8	61.3	62.5	60.9	–
		13	64.7	63.2	62.1	61.7*	+
Calcium	mM	6	2.65	2.67	2.46**	2.46**	+
		13	2.55	2.56	2.53	2.50	–
Females
Calcium	mM	6	2.61	2.62	2.46**	2.42**	+
		13	2.55	2.55	2.46**	2.49*	–
*p ≤ 0.05; **p ≤ 0.01

Table 2: Results of clinical signs and gross pathology
Parameter	Control		20 mg/kg bw		100 mg/kg bw		500 mg/kg bw		Dose-response +/–
	Males ^a	Females^a	Males ^a	Females ^a	Males ^a	Females ^a	Males ^a	Females ^a	males	females
Number of animals examined	10	10	10	10	10	10	10	10
Clinical signs									–	–
restlessness	0/10	10/10	0/10	10/10	0/10	10/10	0/10	10/10		–
Gross pathology
smaller testis	2/10	–	0/10	–	0/10	–	0/10	–	–	–
yellow areas in epididymis	0/10	–	1/10	–	0/10	–	0/10	–	–	–
pale kidney	0/10	0/10	0/10	0/10	0/10	0/10	2/10	1/10	–	–

^anumber of animals affected/total number of animals

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

500 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The NOAEL was found to be the highest dose of 500 mg/kg bw/day for males and females. The database for this endpoint is deemed to be acceptable and sufficient for non-classification.

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The relevant data on repeated dose toxicity for Preventol KMX and the read across substance 4-chloro-3-methylphenol are summarized in the table below. The read across justification and additional data for m-cresol are attached to the Chemical Safety Report in Annex I. In comparison to the chlorocresols, m-cresol is only a minor component of Preventol KMX. Therefore these data are not considered for the assessment of the repeated dose toxicity of Preventol KMX.

Table 1: Comparison of relevant data on repeated dose toxicity of Preventol KMX and 4-chloro-3-methylphenol

Endpoint	Preventol KMX	4-chloro-3-methylphenol
Sub-chronic toxicity	Read across to 4-chloro-3-methylphenol	NOAEL dermal rat 90d: 500 mg/kg bw/day (male), 134 mg/kg bw/day (female)
Chronic toxicity	Read across to 4-chloro-3-methylphenol	NOAEL oral rat 105 weeks: 103 mg/kg bw/day (male / female)

 

No data on repeated dose toxicity for Preventol KMX (reaction mass of 6-chloro-m-cresol, 2-chloro-m-cresol and m-cresol) are available. The possibility of a read-across to Preventol CMK (4-chloro-3-methylphenol) in accordance with Regulation (EC) No 1907/2006 Annex XI 1.5. Grouping of substances and read-across approach was assessed. There it is given that a read-across approach is possible for substances, whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity. Preventol KMX contains of approximately 58% 6-chloro-m-cresol, 30% 2-chloro-m-cresol, 9% m-cresol and smaller amounts of p-cresol (approx. 2.5%), 4-chloro-3-methylphenol (approx. 0.5%) and other impurities (approx. 0.5%). A literature search and QSAR predictions were performed for 2-chloro-m-cresol, 6-chloro-m-cresol using m-cresol and 4-chloro-3-methylphenol as reference substances. Next to physico-chemical properties, environmental fate, ecotoxicity, toxicity, and metabolism of chlorocresols and chlorophenols in various databases, special emphasis was set on determining the effects of different positions of chlorine on aromatic ring structures as this is the determinant difference between the 3 chlorocresol constituents, which may influence outcome in physicochemical and toxicological behaviour. The aim was to evaluate the read-across from 4-chloro-3-methylphenol to Preventol KMX and to ensure a safe and legally valid analogue approach.

 

The chlorocresols are found to be similar in structure and the available data shows that the substances are similar in physico-chemical properties, environmental fate, metabolism and predicted affected pathways. Literature revealed no evidence of relevant influence of the position of chlorination on ring structures on the toxicological properties of a substance. Thus, the position of the chlorination is not regarded to significantly modulate the toxic effects of the chlorocresols. Since the discussed chlorocresols differ only in the position of the chlorination, the toxicological properties of the substances can be expected to be similar. This assumption is also supported by the fact that results of available studies are in the same range for Preventol KMX compared to results of 4-chloro-3-methylphenol. For instance the acute LD50_{oral, rat}for Preventol KMX was found to be > 300 but below 2000 mg/kg bw and for 4-chloro-3-methylphenol the acute LD50_{oral, rat}was found to be < 2000 mg/kg, resulting in a classification as “Harmful if swallowed” for both test materials. Hence, 4-chloro-3-methylphenol is determined as a suitable read-across substance to predict toxicity endpoints in the chemical risk assessment of reaction mass of 6-chloro-m-cresol, 2-chloro-m-cresol and m-cresol (Preventol KMX). A detailed justification for the read-across is provided in the technical dossier (see IUCLID Section 13), as well as in the Chemical Safety Report (see Part B).

 

Available studies of interest for 4-chloro-3-methylphenol:

Repeated dose oral toxicity:

A reliable, GLP compliant 105 week oral toxicity feeding study with doses of 400, 2000 and 10000 ppm 4-chloro-3-methylphenol in the diet was performed according to OECD Guideline 453 with minor deviations (Haematological examinations were performed on 10 instead of 20 rats/sex/group) (Leser, 1993).

Fifty rats per sex and dose level were fed daily with the test substance in a peanut oil solution via food for 105 weeks. Satellite groups, for interim sacrifice, of 10 rats per sex and dose-level received the same doses for 52 weeks. These animals were sacrificed after 52 weeks. The other animals were necropsied after 105 weeks of treatment.

Detailed pre-exposure ophthalmoscopic examinations were performed on 20 animals per sex per dose group. Additional 20 rats per sex of the control and highest dose group were examined ophthalmoscopically after 53 and 104 weeks.

Observations for clinical signs and mortality were made twice daily (once daily on weekends and holidays). Individual body weights were determined before start of treatment, weekly thereafter and prior to necropsy. Food consumption and water intake were performed once per week during week 1 to 13 and monthly thereafter. Water uptake was recorded once per month. A detailed physical examination of all animals was performed before treatment and then weekly thereafter. Blood samples for haematology and clinical chemistry examination were taken after 6, 12, 18, and 24 months. Urine specimens were collected in 16-hour intervals in week 26, 51, 78 and 103. Gross pathological examinations were performed on all surviving animals at termination as well as on all animals dying or sacrificed moribund during the study. Gross pathology was also performed on 10 rats per sex and group sacrificed after 52 weeks of treatment. Organ weights of brain, heart, kidneys (in pairs), liver, ovaries (in pairs), testicles (in pairs) and spleen were determined for all surviving animals at interim and terminal sacrifice. Histopathological examinations were performed with the tissues of all surviving animals at termination and on 10 rats per sex and group sacrificed after 52 weeks of treatment.

The average food consumption over 105 weeks was determined to be 21.0, 103.1 and 558.9 mg/kg bw/day for males and 27.7, 134.3 and 743.5 mg/kg bw/day for females.

Cage side observations revealed that the number of females of the high dose group with poor general condition was higher than in the control group. No treatment-related deaths occurred. Ophthalmological and histopathological investigations showed no toxicological effects on the eyes. At the high dose the body weight gain was delayed in both sexes while not such effect was seen at the mid dose. Feed intake was comparable in all dose groups. Water intake was comparable for all treated females and for males up to and including 2000 ppm. At the high dose, water intake of males was higher than that of controls. No signs of treatment-related damages on haematological parameters or haematopoietic organs were seen (haematology, histopathology). Urine analyses, organ weights, gross pathological and histopathological investigations revealed no treatment-related effects in females up to and including 10,000 ppm and in males up to and including 2000 ppm. In males of the mid dose group kidney weights were slightly increased. Males of the high dose group exhibited papillary necroses, cortical dilatations and fibroses of the kidneys, which were regarded as test substance induced. Clinical chemistry, gross pathological and histopathological examinations as well as organ weight determinations showed no indication of test substance related damage to any other organ or metabolic function.

Gross pathological and histopathological investigations gave no indication of carcinogenic effects of the test compound at doses up to and including 10,000 ppm.

Therefore the NOAEL was found to be the mid dose, corresponding to a NOAEL of 103 mg/kg bw/day for males and 134 mg/kg bw/day for females.

Repeated dose dermal toxicity:

In a reliable GLP compliant OECD guideline 411 study 4-chloro-3-methylphenol was applied to wistar rats dermally on 5 days/week and 6 h/day under occlusive conditions at doses of 20, 100 and 500 mg/kg bw for 13 weeks (Leser, 1991). The test substance was removed by wiping with Polyethylenglycol 400 (also used as vehicle).

Cage side observations were performed at least daily. Detailed clinical observations were performed once weekly. Further observations comprised of the assessment of body weights, food- and water consumption as well as the investigation of blood samples (haematology and clinical chemistry) and urine. In addition ophthalmoscopic examination was performed. The thickness of skin folds were examined in all animals on treatment days 20 and 60. All animals which died during the conduct of the study and all animals sacrificed upon study termination were subjected to gross pathology. Organ weights were assessed and histopathology was performed on all animals of the control and the highest dose group and on liver, lungs and kidneys of all animals of the low and mid dose groups.

No mortalities occurred. All females of all dose groups showed an unsettled behavior (increased motility with bounding, throwing down, jumping off, running around, biting into cage cover and occlusion) during the first 10 treatment days. These symptoms decreased from day 11 to 13 and were not observed from day 14 onwards. Body weight gain, food-consumption and water-intake of the treated animals were comparable to those of the control group. Haematological and clinical chemistry examinations as well as urine analyses revealed no treatment-related effects. Upon gross pathology two males and one female of the high dose group had a pale kidney, however without histopathological correlates. Therefore, this effect was not considered to evidence organ damage. Examination of the skin thickness revealed no significant differences between the control and test substance groups. No treatment related effects were noticed during the histopathological examination and of the absolute and relative organ weights. Thus, the NOAEL was the highest dose of 500 mg/kg bw/day.

 

Repeated dose inhalation toxicity:

No data regarding the acute toxicity via the inhalation route are available.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
Reliable, GLP compliant OECD Guideline 453 study

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:
Reliable, GLP compliant OECD guideline 411 study

Justification for classification or non-classification

Preventol KMX has not to be classified according to Dangerous substance directive 67/548/EEC and according to CLP (1272/2008/EC).