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

Repeated dose toxicity: oral

Administrative data

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.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

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

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
- Analytical purity: 99.90% (batch 792) and 99.70% (batch 458)
- Lot/batch No.: 792 and 458
- Stability under test conditions: Stability of the test substance in feed was confirmed for the study period.

Test animals

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)

Administration / exposure

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.

Doses / concentrations

Doses / concentrations 1

Remarks:

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

Doses / concentrations 2

Remarks:

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

Doses / concentrations 3

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

Examinations

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.

Results and discussion

Results of examinations

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.

Effect levels

1

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

2

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

3

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

4

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.

5

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.

6

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.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

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