2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol]

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 22 - August 10, 1993.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed in accordance with OECD & EU test guidelines in compliance with GLP and reported with a GLP certificate.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol]

EC Number:

201-044-5

EC Name:

2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol]

Cas Number:

77-62-3

Molecular formula:

C29H40O2

IUPAC Name:

2-{[2-hydroxy-5-methyl-3-(1-methylcyclohexyl)phenyl]methyl}-4-methyl-6-(1-methylcyclohexyl)phenol

Test material form:

other: soild

Details on test material:

Name: Mutterlaugenrückstand
Batch No.: Fil-1248
Chemical name: not specified by the sponsor
Physical state: solid
Density: 1.04 g/ml
Identification: labelled, where appropriate, with name of test article, batch no., name of sponsor, project no., date of receipt, storage conditions, handling precautions and expiry date
Storage: ambient, 20 ± 2°C

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Species: rat
Strain: Bor: WISW (SPF Cpb)
Source: Fa. Harlan Winkelmann, Versuchstierzucht GmbH & Co. KG, Garenstr. 27, 33178 Borchen
Date of receipt: July 14, 1993 (range finding); July 21, 1993 (main test, male); July 14, 1993 (main test, female)
Acclimatization period: at least 5 days
Animal selection: random
Animal identification: with colored markings; cage labelled with dosage, sex, date of study initiation, project no.
Weight range at study initiation: m: 188 - 198 g, f: 177 - 205 g

Husbandry
Housing: individual housing in cages (Makrolon® type II)
Illumination: artificial lighting (120 lux) from 7.00 a.m. - 7.00 p.m.
Temperature: 22 ± 3°C
Relative humidity: 30 - 70 %
Measurement: with thermohygrometer twice daily

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

Pre-experimental procedure
Prior to study initiation, the animals were acclimatized to laboratory conditions for at least 5 days. Only healthy animals were used in the test.
24 h before treatment, the fur was removed with electric clippers from an area of roughly 5 x 10 cm on the back of each animal. The skin was subsequently examined for abrasions and animals with healthy, intact skin were then colored for individual identification.

Preparation and application of the test article
A single dermal application of the test article was performed. The substance was held in contact with the skin with a porous gauze dressing and Elastoplast® (Beiersdort).
The exposure period was 24 h. Prior to application and during the application procedure the test substance was liquified by heating up to approx. 50°C and stirring.
The test article was applied in a volume of 1.92 ml/kg.

Duration of exposure:

24 hours

Doses:

Single dose of 2000 mg/kg bw

No. of animals per sex per dose:

2 females for the dose range finding study
5 males & 5 females in the main study

Control animals:

not specified

Details on study design:

Range finding
A preliminary range finding test with a dose of 2000 mg/kg body weight was conducted on two female rats.

Main study
Clinical observations
In each animal a number of clinical-toxicological signs were evaluated according to a modified Irwin-Screening procedure (Screening Methods in Pharmacology, R. A. Turner, 1965, p. 26). The animals were examined at the following post-treatment intervals: 10 min, 1 h, 2 h, 6 h, 24 h, and thereafter once daily up to day 14.
Skin reactions
After patch removal, dermal irritation was evaluated once daily for 14 days according to a scheme based on Draize.
Body weights
Body weights were recorded immediately before treatment (day 0) and on days 7 and
14 p.a. (termination).
Necropsy
The animals were sacrificed by CO2 asphyxiation after 14 days and gross pathological examinations were subsequently performed.

Statistics:

None spceified in the study report.

Results and discussion

Preliminary study:

There were no deaths in the preliminary study.

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No animals died during the course of the main study.

Clinical signs:

No abnormal clinical signs were observed.

Body weight:

Weight gains were normal in all aiumals.

Gross pathology:

Gross pathological examinations at 14 days p. a. (terminal necropsy) revealed no test article-dependent findings. Those macroscopic changes observed were attibutable to minor variations which can occur spontaneously in rats of this strain and age.

Other findings:

Very slight erytema was observed in 3 different animals at the day 3, 4 or 7 p.a. At day 6 p.a. a redness of the marginal areas was seen in 7 animals. A formation of scab was observed in some animals between the days 7 and 13 p.a.

Any other information on results incl. tables

INDIVIDUAL DOSES AND PRE-TREATMENT DEATHS – RANGE FINDING

Test article: Mutterlaugenrückstand               Project No.: 10-04-0064/00-93

Species: Rat                                           Animal No.: 6, 7

Sex: f

Animal No.	Sex	Dose (mg/kg)	Volume (mL)	Pre-terminal deaths
				24h	48h	Days p.a.
						3	4	5	6	7	8	9	10	11	12	13	14
6	F	2000	0.34
7	F	2000	0.35

Open boxes: no pre-terminal deaths

 

INDIVIDUAL DOSES AND PRE-TREATMENT DEATHS – MAIN STUDY

Test article: Mutterlaugenrückstand               Project No.: 10-04-0064/00-93

Species: Rat                                           Animal No.: 1 - 10

Sex: m + f                                              Dose: 2000 mg/kg

Animal No.	Sex	Dose (mg/kg)	Volume (mL)	Pre-terminal deaths
				24h	48h	Days p.a.
						3	4	5	6	7	8	9	10	11	12	13	14
1	M	2000	0.36
2	M	2000	0.38
3	M	2000	0.36
4	M	2000	0.36
5	M	2000	0.37
6	F	2000	0.34
7	F	2000	0.35
8	F	2000	0.39
9	F	2000	0.37
10	F	2000	0.35

Open boxes: no pre-terminal deaths

 

CLINICAL OBSERVATIONS

Test article: Mutterlaugenrückstand               Project No.: 10-04-0064/00-93

Species: Rat                                           Sex: m, f

Dose mg/kg	Observation period p.a.	Findings
2000	10 min – day 14 (10/10)	No abnormal clinical signs

Figures in parenthesis indicate number of surviving animals

 

BODY WEIGHTS – INDIVIDUAL VALUES (g)

Dose: 2000 mg/kg

Anim. No.	Sex	Day 0	Day 7 p.a.	Day 14 p.a.
1	M	188	212	240
2	M	198	224	265
3	M	190	210	245
4	M	188	199	222
5	M	194	224	250
6	F	177	192	194
7	F	182	198	201
8	F	205	206	210
9	F	191	200	202
10	F	182	179	185

 

BODY WEIGHTS – MEAN VALUES (g)

Sex	N	Day 0	Day 7 p.a.	Day 14 p.a.
Males	5	191.6 ± 4.3	213.8 ± 10.5	244.4 ± 15.6
Females	5	187.4 ± 11.1	195.0 ± 10.2	198.4 ± 9.4

 

INDIVIDUAL VALUES OF SKIN REACTION

Test article: Mutterlaugenrückstand               Project No.: 10-04-0064/00-93

Species: Rat                                           Dose: 2000 mg/kg

Sex: m, f

Animal No.	Sex	Days p.a.
		1		2		3		4		5		6		7
		Ery	Oed	Ery	Oed	Ery	Oed	Ery	Oed	Ery	Oed	Ery	Oed	Ery	Oed
1	M	0	0	0	0	0	0	0	0	0	0	0+	0	0*	0
2	M	0	0	0	0	1	0	0	0	0	0	0+	0	0*	0
3	M	0	0	0	0	0	0	0	0	0	0	0+	0	0*	0
4	M	0	0	0	0	0	0	0	0	0	0	0+	0	0*	0
5	M	0	0	0	0	0	0	0	0	0	0	0	0	0	0
6	F	0	0	0	0	0	0	1	0	0	0	0	0	0	0
7	F	0	0	0	0	0	0	0	0	0	0	0	0	0	0
8	F	0	0	0	0	0	0	0	0	0	0	0+	0	0*	0
9	F	0	0	0	0	0	0	0	0	0	0	0+	0	0*	0
10	F	0	0	0	0	0	0	0	0	0	0	0+	0	1*	0

Ery = Erythema

Oed = Oedema

+ = redness of the marginal area

* = formation of scab

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

According to the requirements of the limit test, the LD50 values after 24 hand 14 days were as follows:
male and female > 2000 mg/kg

Executive summary:

The aim of the test was to determine the acute median lethal dose of "Mutterlaugenrückstand". Information derived from this test serves to indicate the existence of possible hazards likely to arise from short-term exposure to the test article by the dermal route.

The test was conducted according to the OECD guideline for the testing of chemicals OECD 402 (February 24, 1987) and to the EEC directive 92/69 EEC (December 29, 1992). The study was cairried out as described in the corresponding protocol approved by the testing facility and the study sponsor on June 28 and July 1, 1993, respectively.

The principles of Good Laboratory Practice for the testing of chemicals as specified by national (BGBI. I, no 13, § 19 a, March 22, 1990) and international (OECD, Paris, 1982) legislation were followed during the performance of the study.

 

SUMMARY

The acute dermal toxicity of "Mutterlaugenrückstand" was investigated in 5 male and 5 female Wistar rats.

On the basis of the range finding results, each animal was given a single dermal administration of "Mutterlaugenrückstand" at a dose of 2000 mg/kg body weight.

The skin was exposed to the test article for 24 h and signs of erythema and oedema were subsequently evaluated once daily for 14 days.

Clinical observations were conducted at regular intervals during the 14-day observation period. Body weights were measured at days 0, 7 and 14 p.a. Gross pathological examinations were performed on animals at termination.

 

The following results were obtained:

1. No abnormal clinical signs were observed.

2. Very slight erythema was observed in 3 different animals at the day 3, 4 or 7 p.a. Redness of the marginal areas (at day 6 p.a.) and formation of scab were seen in some animals.

3. Weight gains were normal in all animals.

4. Gross pathological examinations at 14 days p.a. (terminal necropsy) revealed no test article-dependent findings.

5. According to the requirements of the limit test, the LD50 values after 24 h and 14 days were as follows:

male and female > 2000 mg/kg

6. The above value is higher than the limit specified as harmful by the EEC directive 91/325/EEC When applied to the skin, the test article "Mutterlaugellrückstand" may therefore be classified as "non-toxic".