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

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 18 - April 2, 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

Report date:

1993

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

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:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Name: Lowinox PSW
Batch No.: not specified by the sponsor
Chemical name: 2,2’-Dihydroxy- 3,3’-di (α-methylcyclohexyl)-5 ,5’-dimethyl-diphenylmethane (as specified by the sponsor)
Active component: 100% (as specified by the sponsor)
Purity: 98 (as specified by the sponsor)
Physical state: white powder
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
Stability: not specified by sponsor

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Species: rabbit
Strain: White New Zealand
Source: Harald Schriever; Kaninchenfarm, D-2740 Bremervörde, Neuendamm 88
Animal selection: random
Animal identification: with individual ear tags; cage labelled with ear tag no., sex, date of study initiation, project no.

Husbandry
Housing: individual housing (50 x 45 x 40 cm, L x B x H) in a battery of cages, each equipped with a paper roll disposal system
Illumination: artificial lighting (120 lux) from 7.00 a.m. - 7.00 p.m.
Temperature: 20 ± 3° C
Relative humidity: 30 - 70 %
Measurement: with thermohygrometer twice daily

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.5g

Duration of treatment / exposure:

4 hour

Observation period:

72 hours

Number of animals:

3 animals

Details on study design:

Preparation if the animals
24 h before treatment, fur was removed with electric clippers from an area of roughly 8 x 15 cm on the back of each animal. The skin was examined for abrasions and only animals with healthy, intact skin were used in the test.

Preparation of the test article
The test article was moistened sufficiently with Aqua ad iniectabilia to ensure a good contact with the skin.

Exposure
In each animal, 0.5 g of the test article were applied to the test site (ca. 6 cm2 in size), an adjacent area of untreated skin serving as a control. Each test area was covered with a semi-occlusive dressing consisting of Ypsiplast® (Holthaus Medical, Remscheid-Lüttringhausen), which was held in place by non-irritating tape Elastoplast® (Beiersdorf AG, Hamburg), and Stülpa® (P. Harmann AG, Heidenheim-Brenz), which enveloped the whole of the animal's trunk. At the end of the 4-h exposure period, the dressing was removed and any residual sample was carefully washed off with water or an appropriate solvent.

Observations
Animals were examined for signs of skin reactions at 30-60 min, 24, 48 and 72 h after patch removal. The skin was evaluated according to the scheme presented in table form (see Any other information).

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 0, 24, 48 & 72h

Score:

0

Max. score:

4

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 0, 24, 48 & 72h

Score:

0

Max. score:

4

Irritant / corrosive response data:

No test artcle-dependent findings were observed.

Other effects:

No toxic effects were observed.

Any other information on results incl. tables

Individual values of skin reactions

Animal number	Time after patch removal
	30-60 min		24h		48h		72h
	Ery	Oed	Ery	Oed	Ery	Oed	Ery	Oed
	T C	T C	T C	T C	T C	T C	T C	T C
1	0 0	0 0	0 0	0 0	0 0	0 0	0 0	0 0
2	0 0	0 0	0 0	0 0	0 0	0 0	0 0	0 0
3	0 0	0 0	0 0	0 0	0 0	0 0	0 0	0 0

T = test site

C = control site

Ery = erythema

Oed = oedema

 

Mean values of skin reactions of 24, 48 and 72h after patch removal

Animal number	Erythema (test site)	Oedema (test site)
1	0.0	0.0
2	0.0	0.0
3	0.0	0.0

 

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The mean grades of skin reactions at 24, 48 and 72 h after patch removal were lower than the value classified as irritant by the EEC directive 91/325/EEC of March 1, 1991. When applied to the skin, the test article "Lowinox PSW" may therefore be considered to be non-irritant.

Executive summary:

The aim of the test was to assess the irritant and/or corrosive effect(s) of "Lowinox PSW" on the skin. Information derived from this test serves to indicate the existence of possible hazards likely to arise from exposure of the skin to the test article.

The test was conducted according to the OECD guideline for the testing of chemicals no. 404 (May 12, 1981) and the EEC directive 84/449/EEC (September 19, 1984). The study was carried out as described in the corresponding protocol approved by the testing facility and the study sponsor on February 12 and 24, 1993, respectively. The principles of Good Laboratory Practice for the testing of chemicals as specified by national (BGB1. I, no. 13, § 19a, March 22, 1990) and international (OECD, Paris, 1982) legislation were followed during the performance of the study.

 

SUMMARY

The potential toxicity of "Lowinox PSW" was assessed in an acute dermal irritation/corrosion test on 3 albino rabbits. The skin was exposed to the test article for 4 h. Animals were examined for signs of erythema and oedema at 30-60 min, 24, 48 and 72 h after patch removal.

 

Results

No test article-dependent findings were observed.

 

The mean grades of skin reactions at 24, 48 and 72 h after patch removal were lower than the value classified as irritant by the EEC directive 91/325/EEC of March 1, 1991. When applied to the skin, the test article "Lowinox PSW" may therefore be considered to be non-irritant.