2,2'-dimethyl-4,4'-methylenebis(cyclohexylamine)

Endpoint summary

Description of key information

The substance did not cause skin sensitisation in two in vivo studies.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

pre-GLP study according to original description of the GPMT; no positive control used, however, several simultaneously tested compounds were positive thus providing the sensitivityof the test system.

Principles of method if other than guideline:

Magnusson & Kligman: The identification of contact allergens by animal assay. The guinea pig maximization test. J Invest Dermatol 52: 268, 1969.

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study was conducted well before LLNA guideline was available.

Species:

guinea pig

Strain:

not specified

Sex:

not specified

Route:

intradermal

Vehicle:

other: acetone

Concentration / amount:

Induction: 0.5 % intracutaneous
Induction: 0.5 % occlusive epicutaneous
Challenge: 2 % occlusive epicutaneous

Route:

epicutaneous, occlusive

Vehicle:

other: acetone

Concentration / amount:

Induction: 0.5 % intracutaneous
Induction: 0.5 % occlusive epicutaneous
Challenge: 2 % occlusive epicutaneous

No. of animals per dose:

15

Details on study design:

Induction:
The test animals were given subcutaneous and topical applications of the test substance in acetone and/or Freund's Complete Adjuvant at a final concentration of 0.5%. Control animals received the corresponding vehicle.

Challenge:
At two weeks after the last induction, animals of both the test and control group received a topical application of the test substance in acetone at a final concentration of 2% (24-hour occluded patch). The skin was scored at 24 hours after removal of the test patch.

Criteria for selection of induction concentration was systemic toxicity reported in the literature. Criteria for selection during induction is not given. No criteria for selection of challenge concentration was given. Number of animals reacting during induction is not given.

Positive control substance(s):

yes

Remarks:

CFA

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

2%

No. with + reactions:

0

Total no. in group:

15

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

15

Key result

Reading:

1st reading

Group:

positive control

Remarks on result:

not measured/tested

No skin reactions were observed after challenge in both test (0/15) and control animals.

Interpretation of results:

GHS criteria not met

Reference 2

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

an in vitro skin sensitisation study does not need to be conducted because adequate data from an in vivo skin sensitisation study are available

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A guinea pig maximisation test was considered as key, as the study was performed comparable to OECD guideline 406 (Thorgeirsson, 1978). The pre-GLP study was conducted according to original description of the GPMT. No positive control was used; however, several simultaneously tested compounds were positive thus proving the sensitivity of the test system. The induction concentration was selected because of systemic toxicity reported in the literature. Intradermal and topical induction was performed with 0.5% test compound in acetone, dermal challenge with 2% test compound in acetone. None of the animals (0/15) showed a positive result.

The result of this study was supported by the skin painting test with guinea pigs (BASF AG, 1956). In that study, no sensitising potential (0/10) was observed (1st induction: undiluted, 2nd induction: 10%, challenge: 1%, all open epicutaneous).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Classification, Labeling, and Packaging Regulation (EC) No 1272/2008

The available test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on this information, the substance is not considered to be classified for skin sensitisation under Regulation (EC) No 1272/2008, as amended for the twelfth time in Regulation (EU) 2019/521.