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

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

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.

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

Species:

guinea pig

Strain:

other: Albino

Sex:

not specified

Details on test animals and environmental conditions:

- Age at study initiation: Young adult.

Route:

intradermal

Vehicle:

other: Saline

Concentration / amount:

0.1 percent dilution in saline.

Route:

intradermal

Vehicle:

other: Saline

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

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.

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.

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.

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In the key study, the potential of the test material to induce a sensitising reaction in the albino guinea pig was assessed in accordance with the method of Draize, as published in the Food-Drug-Cosmetic Law Journal,10, 679, (1955). The study was performed to a good standard with a sufficient level of reporting to assess the quality of the submitted data, accordingly the study was assigned a reliability score of 2 in line with Klimisch (1997).

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.

The irritation observed in this study is in agreement with the findings presented for dermal irritation, where slight reactions were observed below the limits of classification.

Migrated from Short description of key information:
Non-sensitising, study conducted according to Draize 1955.

Justification for selection of skin sensitisation endpoint:
Study conducted in accordance with sound scientific principles, with a sufficient level of reporting to assess the quality of the data submitted. The study was assigned a reliability score of 2 in line with the principles set forth by Klimisch (1997).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

According to the criteria outlined in Regulation (EC) No. 1272/2008 and Directive 67/548/EEC, this substance does not meet the criteria for classification as a skin sensitizer.