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

Repeated dose toxicity: dermal

Administrative data

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.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chlorocresol

EC Number:

200-431-6

EC Name:

Chlorocresol

Cas Number:

59-50-7

Molecular formula:

C7H7ClO

IUPAC Name:

4-chloro-3-methylphenol

Details on test material:

- Name of test material (as cited in study report): Preventol CMK
- Physical state: Colourless powder
- Purity: 99.96%
- Stability under test conditions: Stability of pure substance and substance in vehicle was confirmed for the study period.

Test animals

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)

Administration / exposure

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

Doses / concentrations

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

Examinations

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.

Results and discussion

Results of examinations

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.

Effect levels

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.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

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