Reaction mass of 1H-Benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-6-methyl- and 2H-Benzotriazole-2-methanamine, N,N-bis(2-ethylhexyl)-5-methyl- and N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methylamine and 2H-Benzotriazole-2-methanamine, N,N-bis(2-ethylhexyl)-4-methyl- and N,N-bis(2-ethylhexyl)-5-methyl-1H-benzotriazole-1-methylamine

Endpoint summary

Description of key information

In the key study, 5 out of 20 guinea pigs gave positive results after challenge exposure and 7 out of 20 after rechallange exposure with the test article. Based on the evaluation criteria of Annex I of Regulation 1272/2008 (CLP), the evalutation " sensitizing" is warranted when at least 30% of the test animals exhibit positive skin reactions in an adjuvant test. Therefore, in line with the above argument, the test article is considered sensitizing after skin contact.

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:

November 7, 1990 - February 7, 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The study was conducted in 1991, when the GPMT was the internationally accepted and recommended study type in order to assess sensitizing potential of a substance.

Species:

guinea pig

Strain:

other: Pirbright White strain (Tif:DHP)

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: from Ciba Geigy Limited, Animal Production, 4332 Stein, Switzerland
- Age at study initiation: approximately 10 weeks
- Weight at study initiation: between 338 and 437 g
- Housing: housed individually in Macrolon cages (Type 3)
- Diet: standard guinea pig pellets (NAFAG no. 845, Gossau SG); ad libitum
- Water: ad libitum
- Acclimation period: 8 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3°C
- Humidity (%): 30 - 70%
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal

Vehicle:

other: sesame oil

Concentration / amount:

3 %

Day(s)/duration:

day 0

Route:

epicutaneous, occlusive

Vehicle:

other: vaseline

Concentration / amount:

10 %

Day(s)/duration:

week 2 / 48 h

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: vaseline

Concentration / amount:

3 %

Day(s)/duration:

week 5 / 24 h

No. of animals per dose:

20 (10 males and 10 females)

Details on study design:

INDUCTION:
- 2-stage operation
- First induction: 3 pairs of intradermal injections (0.1 mL per injection) made simultaneously into the shaved neck of the guinea pigs as follows:
adjuvant/saline mixture 1:1 (v/v)
test article in sesame oil (3%) (w/v)
test article in the adjuvant saline mixture (w/v)
- Second induction: in the second week, the test article was incorporated in vaseline (10%) (w/w) and applied on a filterpaper patch to the neck of the animals (patch 2 x 4 cm, approximately 0.4 g paste per patch
Occluded administration for 48 hours.
A control group (20 animals: 10 males and 10 females) was treated with adjuvant and the vehicle during the induction period.

REST PERIOD:
no treatment performed during weeks 3 and 4

CHALLENGE:
Animals were tested on the flank with the test article in vaseline (3%) (w/w) or the vehicle alone (patch 2 x 2 cm, approximately 0.2 g paste per patch)
Occluded administration for 24 hours.
During the challenge period, the control group of the induction was treated with the vehicle as well as with the test article to check the maximum subirritant concentration of the test article in adjuvant treated animals.

Challenge controls:

A control group (20 animals: 10 males and 10 females) was treated with adjuvant and the vehicle during the induction period.
During the challenge period, the group was treated with the vehicle as well as with the test article to check the maximum subirritant concentration of the test article in adjuvant treated animals.

Positive control substance(s):

yes

Remarks:

sensitivity checked every 6 months: potassium dichromate

Positive control results:

Incidence of positive animals per group after epidermal challenges 24 hours after removing of bandages:
7/10 for erythema
5/10 for edema

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

3%

No. with + reactions:

5

Total no. in group:

20

Clinical observations:

(effects only in females)

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

3%

No. with + reactions:

5

Total no. in group:

20

Clinical observations:

(effects only in females)

Key result

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

3%

No. with + reactions:

8

Total no. in group:

20

Clinical observations:

(3 males, 5 females)

Key result

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

3%

No. with + reactions:

7

Total no. in group:

20

Clinical observations:

(2 males, 5 females)

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No toxic symptoms

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No toxic symptoms

Group:

positive control

Remarks on result:

not measured/tested

Results of test group:

Males		Animal number
Challenge		1	2	3	4	5	6	7	8	9	10
24 h	Erythema	0	0	0	0	0	0	0	0	0	0
	Edema	0	0	0	0	0	0	0	0	0	0
48 h	Erythema	0	0	0	0	0	0	0	0	0	0
	Edema	0	0	0	0	0	0	0	0	0	0
Re-Challenge
24 h	Erythema	1	2	0	1	0	0	0	0	0	0
	Edema	0	1	0	0	0	0	0	0	0	0
48 h	Erythema	2	2	0	0	0	0	0	0	0	0
	Edema	1	1	0	0	0	0	0	0	0	0

 

Females		Animal number
Challenge		1	2	3	4	5	6	7	8	9	10
24 h	Erythema	0	1	1	0	1	1	1	0	0	0
	Edema	0	1	2	0	1	1	1	0	0	0
48 h	Erythema	0	1	1	0	1	1	1	0	0	0
	Edema	0	0	2	0	1	1	1	0	0	0
Re-Challenge
24 h	Erythema	0	2	2	1	0	1	2	0	0	0
	Edema	0	1	1	0	0	0	1	0	0	0
48 h	Erythema	0	2s	2s	1	0	2	2s	0	0	0
	Edema	0	1	1	0	0	1	2	0	0	0

s = scaling

In both control groups (vehicle control and test article treated control), there were 0/20 animals with positive responses at 24 and 48 hours after challenge.

Under the experimental conditions employed, 25% of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

Because the reactions were not very strong and the number of positive animals was at the threshold of significance, a second challenge was performed after a further rest period. The control group was not challenged again.

After the second challenge application, the number of positive animals was increased to 40% and the reactions intensified.

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

25 to 40% of the animals were sensitised by the test substance under the experimental conditions employed.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

In the key dermal sensitisation study with the test substance (99% pure) in sesame oil or vaseline, Pirbright White Strain (Tif: DHP) guinea pigs (10 males and 10 females) were tested using the method of the guinea pig maximisation test according to the OECD TG 406. Intradermal and epicutaneous induction (occlusive, 48 h) was performed with 3% (in sesame oil) and 10% (in vaseline) of the test substance, respectively. Epicutaneous challenge exposure (occlusive, 24 h) was performed with 3% (in vaseline) of the test substance. Evaluation of the skin reactions were performed 24 and 48 hours after challenge according to the Draize method. 5/20 animals showed erythema or edema reactions after the challenge treatment corresponding to 25% with positive results (females: 50%, males: 0%). In a rechallenge, performed one week later, 8/20 and 7/20 animals (24 h and 48 h after treatment, respectively) showed positive reactions corresponding to 40% and 35%. This is above the threshold of 30% laid down in Annex I of Regulation 1272/2008 and therefore the substance is considered a dermal sensitizer in this study. The study is suitable for assessment of sensitizing potential as it was performed according to OECD 406 and GLP standards.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

No information available on respiratory sensitisation.

Justification for classification or non-classification

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

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance is considered to be classified as skin sensitizer category 1B (H317: "May cause an allergic reaction") under Regulation (EC) No 1272/2008, as amended for the eighth time in Regulation (EU) No 2016/218.