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

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 March 1957 - 27 December 1957

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1957

Report date:

1957

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: According to the method of Draize as cited in the Food-Drug-Cosmetic Law Journal, 10, 679, (1955).

Deviations:

no

GLP compliance:

no

Type of study:

Draize test

Test material

Test material information

Constituent 1

Reference substance name:

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

EC Number:

232-092-5

EC Name:

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

Cas Number:

7786-17-6

Molecular formula:

C33H52O2

IUPAC Name:

2-[(2-hydroxy-5-methyl-3-nonylphenyl)methyl]-4-methyl-6-nonylphenol

Test material form:

liquid: viscous

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Albino

Sex:

not specified

Details on test animals and environmental conditions:

- Age at study initiation: Young adult.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

other: Saline

Induction 2

Concentration / amount:

0.1 percent dilution in saline.

Challenge

Challenge 1

Route:

intradermal

Vehicle:

other: Saline

Challenge 2

Concentration / amount:

0.1 percent dilution in saline.

No. of animals per dose:

10

Details on study design:

The animals were depilated over a dorsal area of approximately 7 x 10 cm.
The test sample was prepared as a 0.1 percent dilution in saline and injected intracutaneously according to the following schedule:
- An initial does of 0.05 mL was followed by nine successive injections of 0.1 mL on alternate weekdays.
- The 10 induction doses were followed by a 14 day rest interval in which no test material was administered.
- After the interval, a single challenge dose of 0.05 mL was administered.

The various injection sites were scattered over the depilated area (which was kept free of hair by repeated clipping with an electric clipper) and records were kept of the location of each injection.

Reactions at each site were scored in terms of the diameter and height of the wheals (in mm) and the intensity of erythema (on a scale of 0 to 4 for increasing intensity).

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

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

other: Maximum induction reading

Group:

test chemical

Dose level:

0.1 mL

No. with + reactions:

10

Total no. in group:

10

Clinical observations:

The positive results seen were signs of irritation

Remarks on result:

other: Reading: other: Maximum induction reading. Group: test group. Dose level: 0.1 mL. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: The positive results seen were signs of irritation.

Results 2

Reading:

other: Maximum challenge reading

Group:

test chemical

Dose level:

0.05 mL

No. with + reactions:

9

Total no. in group:

10

Clinical observations:

The positive results seen were signs of irritation

Remarks on result:

other: Reading: other: Maximum challenge reading. Group: test group. Dose level: 0.05 mL. No with. + reactions: 9.0. Total no. in groups: 10.0. Clinical observations: The positive results seen were signs of irritation.

Any other information on results incl. tables

Table 1 Skin Reactions in Sensitisation Test

Guinea pig Number	Maximum Scores*
	Induction Sites			Challenge Dose Site
	Diameter of wheal (mm)	Height of wheal (mm)	Degree of Erythema†	Diameter of wheal (mm)	Height of wheal (mm)	Degree of Erythema†
1 2 3 4 5 6 7 8 9 10	7 7 8 8 8 8 7 7 8 5	1 1 1 1 1 1 1 1 1 1	1 1 1 1 1 1 1 1 1 1	4 4 3 3 6 5 4 4 5 0	0 0 0 0 0 1 1 1 1 0	1 1 1 1 1 1 1 1 1 0
Average	7.3	1.0	1.0	3.8	0.4	0.9

*Scored according to Draize

†Scale of 0 to 4 for increasing intensity

 

The intracutaneous injections of the test material produced moderate degrees of irritation. The first sign of irritation developed at the third or fourth injection in most cases and was then apparent in all subsequent doses.

 

However, the challenge injections produced less severe reactions than the induction doses with none of the challenge sites flaring up as a result of the challenge injections.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The skin sensitisation test conducted in the guinea pig showed the test material to be irritating under the conditions of the study but did not induce sensitisation.

Executive summary:

A skin sensitisation study was carried out to assess the potential of the test material to induce a sensitising reaction in the albino guinea pig. The study was carried out according to the method of Draize, as published in the Food-Drug-Cosmetic Law Journal, 10, 679, (1955).

The test material was administered as a 0.1 % dilution and injected intracutaneously. An initial dose of 0.05 mL was followed by nine successive injections of 0.1 mL on alternate weekdays.

Following a rest interval of two weeks, a single challenge dose of 0.05 mL was administered.

The skin reactions were scored on the height and depth of any wheals formed and the intensity of any erythema seen (on a scale of 0 to 4 for increasing intensity)

It was seen that the induction intracutaneous injections produced moderate degrees of irritation. However the challenge injections produced less severe reactions. Therefore this test showed the test material to be slightly irritating under the conditions of the study but did not induce sensitisation.