2,2'-methylenebis(6-nonyl-p-cresol)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study pre-dates GLP and the standard guidelines; nevertheless, data is well summarised and the experiment is conducted in accordance with generally accepted scientific principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1973

Report date:

1973

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Test conducted in accordance with FHSA principles.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

6,6'-di-tert-butyl-4,4'-thiodi-m-cresol

EC Number:

202-525-2

EC Name:

6,6'-di-tert-butyl-4,4'-thiodi-m-cresol

Cas Number:

96-69-5

IUPAC Name:

4,4'-sulfanediylbis(2-tert-butyl-5-methylphenol)

Test material form:

solid: crystalline

Test animals

Species:

rabbit

Strain:

New Zealand White

Test system

Type of coverage:

not specified

Preparation of test site:

other: intact and abraded

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

500 mg applied as a finely ground powder, moistened with water.

Duration of treatment / exposure:

24 hours

Observation period:

7 days

Number of animals:

6

Details on study design:

Local dermal irritation was assessed using the prescribed numerical system:

Erythema and eschar formation:

No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) or eschar formation (injuries in depth) preventing erythema reading 4

Edema formation:

No edema 0
Very slight edema (barely perceptible) 1
Slight edema (edges of area well-defined by definite raising) 2
Moderate edema (edges raised approximately 1 millimetre) 3
Severe edema (raised more than 1 millimetre and extending beyond the area of exposure) 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

overall irritation score

Basis:

mean

Remarks:

score for 6 animals

Time point:

other: Mean score for 24, 48 and 72 hours

Score:

0.9

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Intact and abraded skin

Results 2

Irritation parameter:

erythema score

Basis:

mean

Remarks:

score for 6 rabbits

Time point:

other: Mean of 24, 48 and 72 hours

Score:

0.94

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Intact skin

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

score for 6 rabbits

Time point:

other: Mean of 24, 48 and 72 hours

Score:

0.94

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Abraded skin

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

score for 6 rabbits

Time point:

other: Mean of 24, 48 and 72 hours

Score:

0

Max. score:

4

Remarks on result:

other: Intact skin

Results 5

Irritation parameter:

edema score

Basis:

mean

Remarks:

score for 6 animals

Time point:

other: Mean of 24, 48 and 72 hours

Score:

0

Max. score:

4

Remarks on result:

other: Abraded skin

Any other information on results incl. tables

Table 1 Summary of Results after Exposure

Animal Number

Erythema

Edema

4 hours

24 hours

48 hours

72 hours

7 days

4 hours

24 hours

48 hours

72 hours

7 days

I

A

I

A

I

A

I

A

I

A

I

A

I

A

I

A

I

A

I

A

1 2 3 4 5 6

0 0 0 0 0 0

0 0 0 0 0 0

1 1 1 1 1 1

1 1 1 1 1 1

1 1 1 1 1 1

1 1 1 1 1 1

1 1 0 1 1 1

1 1 0 1 1 1

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

I = Intact skin

A = Abraded skin

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study the test material is not classified in accordance with EU criteria.

Executive summary:

The potential of the test material to cause primary skin irritation was assessed in the New Zealand Albino rabbit.

500 mg of the test material was applied as a finely ground powder moistened with water to the intact and abraded skin of 6 test animals, with exposure lasting for 24 hours. The animals were observed for 7 days.

Slight erythema was evident for the 72 hours following exposure. However these effects were completely reversed after 7 days. No edema was seen.

As a result of this, no classification is required in accordance with EU criteria under the conditions of this study.