N-methyldidecylamine

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The objective of the study of Gerbeix (2010c) was to evaluate the potential of the test item to induce delayed contact hypersensitivity in guinea pigs according to the maximization method of Magnusson and Kligman and to OECD(No. 406, 17th July 1992) and CommissionRegulation (EC) (No. 440/2008, B.6, 30 May 2008)guidelines.The study was conducted in compliance with the principles of Good Laboratory Practice Regulations.

 

 Thirty guinea-pigs were allocated to 2 groups: a control group of 5 males and 5 females and a treated group of 10 males and 10 females.

 On day 1, three pairs of intradermal injections were performed in the interscapular region of all animals:

.            Freund's complete adjuvant (FCA) diluted to 50% (v/v) with 0.9% NaCl (both groups),

.            test item at the concentration of 5% in corn oil (treated group) or vehicle alone (control group),

.            test item at the concentration of 5% in a mixture FCA/0.9% NaCl (50/50, w/w) (treated group) or vehicle at the concentration of 50% (w/v)

in a mixture FCA/0.9% NaCl (50/50, v/v) (control group).

 

On day 8, the treated group animals received a topical application of the test item at the concentration of 50% (w/w) in acetone to the same test site, which was then covered by an occlusive dressing for 48 hours. The control group animals received an application of the vehicle under the same experimental conditions.

 

On day 29, all animals of both groups were challenged by a cutaneous application of the test item at the concentration of 0.1% (w/w) in acetone to the right flank. The test item was maintained under an occlusive dressing for 24 hours. The vehicle was applied to the left flank under the same experimental conditions.

Cutaneous reactions were evaluated in each animal 24, 48 and 72 hours after removal of the dressing.

 

Each animal was observed at least once a day for mortality and clinical signs during the treatment and observation periods. Body weight was recordedon the day of allocation into the groups, on day 1 and day 25.

On completion of the observation period, the animals were sacrificed then discarded without macroscopicpost-mortemexamination. Skin samples were takeneach flank (challenge application sites) of all animals.No histological examination was performed.

 

No unscheduled mortality and no clinical signs were recorded in any animals.After the challenge application of the test item, a moderate erythema was noted on the right flank (test item application) of 1/10 animals at the72-hour reading. A discrete erythema was observed on the right flank of 6/10, 5/10 and 0/10 animals of the control group at the 24, 48 and 72-hour readings, respectively. Dryness of the skin was also recorded in 6/10 animals. No cutaneous reactions were noted on the left flank (vehicle application) of the control animals during the whole challenge phase.

In the treated group, a moderate erythema was recorded on the right flank (test item application) of 4/20 and 1/20 animals at the 48 and 72-hour reading. A discrete erythema was noted on the right flank of 13/20, 11/20 and 3/20 animals at the 24, 48 and 72-hour readings, respectively. Dryness of the skin was recorded in 5/20 and 15/20 animals at the 48 and 72-hour readings, respectively. A severe dryness of the skin masked the evaluation of cutaneous reactions in 5/20 animals at the 72-hour reading. No cutaneous reactions were noted on the left flank (vehicle application) of the treated animals.

 

A higher incidence and severity in local reactions was noted on 20% of the animalsof the treated group at the 48-hour reading. However, as the cutaneous reactions observed at the 24 and 72-hour readings in the animals of the treated group were of similar incidence and severity when compared to those recorded in the animals of the control group, they were attributed to the irritant properties of the test item but not to delayed contact hypersensitivity.

 

Therefore, under the experimental conditions of this study,the test itemdid not induce delayed contact hypersensitivity in guinea pigs.

 

Migrated from Short description of key information:
The potential of the substance to induce delayed contact hypersensitivity was investigated using the Maximization method of Magnusson and Kligman(OECD 406, GLP) . The test item was found to be non-sensitising.

Respiratory sensitisation

Endpoint conclusion

Additional information:

Migrated from Short description of key information:
There is no reported case of respiratory sensitisation in humans.

Justification for classification or non-classification

Skin sensitisation:

According to the results of the guinea-pig maximization test and the criteria laid down in EU regulation (EC) n°1272/2008 (CLP) and EU Directive 67/548/EEC, the substance is not classified for skin sensitisation.