Amides, C16-C18 (even) , N,N'-ethylenebis

Endpoint summary

Description of key information

skin sensitisation in vivo (OECD 429, LLNA): not sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 - 29 April 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

adopted April 2002

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Janvier, Le Genest-Saint-Isle, France
- Age at study initiation: young adult, approx. 9 weeks old
- Weight at study initiation: variation was within +/- 20% of the sex mean (range 21 to 25 g)
- Housing: Individual housing in labeled Macrolon cages (MI type; height 12.5 cm) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France). Paper (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom) was supplied as cage-enrichment. The paper was removed on Day 1 prior to dosing and was supplied again after scoring of the ears on Day 3.
- Diet: free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: free access to tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 (actual range: 18.9 – 23.2)
- Humidity (%): 40-70 (actual range: 37 – 84)
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 14 To: 29 April 2010

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

10, 25 or 50% w/w

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
Concentrations of 25% and 50% were tested in order to determine the highest test substance concentration to be used in the study, which should be well tolerated systemically and may give moderate irritation.
- Irritation: slight irritation (erythema and edema score of 1 of max. 4) was noted with 50% test substance

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay (LLNA)
- Criteria used to consider a positive response: If the results indicate a SI ≥ 3, the test substance may be regarded as a skin sensitiser, based on the test guideline and recommendations done by ICCVAM. The results were evaluated according to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations (2007) and the Regulation (EC) No. 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labeling and packaging of substances and mixtures. Consideration was given to the EC3 value (the estimated test substance concentration that will give a SI =3).

TREATMENT PREPARATION AND ADMINISTRATION:
In the main study, three experimental groups of five female CBA/J mice were treated with test substance concentrations of 10, 25 or 50% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone (Acetone/Olive oil (4:1 v/v)). Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after 5 h the draining (auricular) lymph nodes were excised and pooled for each animal. After precipitating the DNA of the lymph node cells, radioactivity measurements were performed.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Positive control results:

The SI values calculated for the positive control substance concentrations 5, 10 and 25% were 1.7, 2.7 and 8.8 respectively. Based on the results, it was concluded that the Local Lymph Node Assay in the mouse as supplied by Janvier performed at NOTOX is an appropriate model for testing for contact hypersensitivity.

Key result

Parameter:

SI

Value:

1.2

Test group / Remarks:

10%

Key result

Parameter:

SI

Value:

1.3

Test group / Remarks:

25%

Key result

Parameter:

SI

Value:

0.9

Test group / Remarks:

50%

Key result

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 210, 235 and 163 DPM, respectively. The mean DPM/animal value for the vehicle control group was 176 DPM.

Table 1: Individual animal scores

Group	concentration [% w/w]	animal	DPM	SI
1	0	1	256	1.45620023
		2	300	1.70648464
		3	137	0.77929465
		4	65	0.36973834
		5	121	0.68828214
		mean	175.8	1
		SEM	44	0.4
2	10	1	245	1.39362912
		2	262	1.49032992
		3	215	1.22298066
		4	54	0.30716724
		5	273	1.55290102
		mean	209.8	1.19340159
		SEM	40	0.4
3	25	1	211	1.20022753
		2	132	0.75085324
		3	137	0.77929465
		4	413	2.34926052
		5	280	1.592719
		mean	234.6	1.33447099
		SEM	52	0.4
4	50	1	147	0.83617747
		2	219	1.24573379
		3	118	0.67121729
		4	178	1.01251422
		5	153	0.87030717
		mean	163	0.92718999
		SEM	17	0.3

DPM: Disintegrations Per Minute

SI: Stimulation Index

SEM: Standard Error of Mean

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No. 1272/2008.

Executive summary:

Based on these results, the test substance does not need to be regarded as skin sensitiser according to the criteria of Regulation (EC) No. 1272/2008.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There is data on skin sensitisation available from a Local Lymph Node Assay performed with test substance concentrations of 10, 25 and 50% according to OECD guideline 429 (NOTOX, 2010). The animals of the respective groups were treated on 3 consecutive days, and skin reactions were assessed on day 3. The slight irritation of the ears was considered not to have a toxicologically significant effect on the activity of the lymph nodes, only slight erythema of the ears was observed in the animals of the group treated with 50% of test substance. The auricular lymph nodes were excised on day 6, and the relative size of the nodes and the incorporated radioactivity of the lymph node cells were assessed.

The stimulation indices for the substance concentrations 10, 25 and 50% were 1.2, 1.3 and 0.9, respectively. Since there were no SI values greater than 3 when tested up to 50%, the test substance was considered not to be a skin sensitiser. The established EC3 value exceeds a concentration of 50%.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on skin sensitisation of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.