Formaldehyde, reaction products with diethanolamine and 6(or 7)-methyl-1H-benzotriazole

Endpoint summary

Description of key information

In the key study, 5 out of 20 guinea pigs gave positive results after challenge exposures and 9 out of 20 after rechallenge exposure with the test article. Based on the evaluation criteria of Annex I of Regulation 1272/2008 (CLP), the evaluation "sensitising" is warranted when at least 30% of the test animals exhibit positive skin reactions in an adjuvant test. Therefore, the test article is considered sensitising 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:

August 9; 1990 - November 9, 1990

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

Remarks:

CIBA-GEIGY Limited, Toxicology Services, Dermatotoxicology, 4002 Basel / Switzerland

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A valid maximization study with guinea pigs is available, no further animal studies are necessary

Species:

guinea pig

Strain:

other: Pirbright White (Tif: DHP)

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Ciba Geigy Ltd., Tierfarm, Stein, Switzerland
- Age at study initiation: approx. 10 weeks
- Weight at study initiation: 363 g to 461 g
- Housing: individually in Macrolon cages (type 3)
- Diet: standard guinea pig pellets, NAFAG No. 845, Gossau SG; ad libitum
- Water: ad libitum
- Acclimation period: no data

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

Route:

intradermal

Vehicle:

physiological saline

Concentration / amount:

1%

Day(s)/duration:

1 week

Route:

epicutaneous, occlusive

Vehicle:

other: vaseline

Concentration / amount:

30%

Day(s)/duration:

48h

Route:

epicutaneous, occlusive

Vehicle:

other: vaseline

Concentration / amount:

10%

Day(s)/duration:

24h

No. of animals per dose:

20 (10 males, 10 females)

Details on study design:

RANGE FINDING TESTS:
1, 3 and 5% suspensions of the test substance in saline was tested intradermally in separate animals. Because necrosis were induced with the 3 and 5% concentrations, the 1% concentration was used for the intradermal induction injections.
30, 10 and 3% of the test substance in vaseline have been examined on separate animals for the evaluation of the primary irritant potential and the maximum subirritant concentration. The tested concentrations did not induce erythema reactions. 30% was therefore selected for the epidermal induction application. 10% was used as subirritant concentration for the challenge application because a higher concentration may lead to nonspecific reactions in adjuvant treated animals.

MAIN STUDY
A1. INDUCTION EXPOSURE (intradermal, first week)
- No. of exposures: 3 pairs of injections (0.1 mL per injection) were made simultaneously
- Test groups: a) adjuvant/saline mixture 1:1 (v/v); b) test article in physiological saline (w/v); c) test article in the adjuvant saline mixture (w/v)
- Control group: as test group, but without test article
- Site: shaved neck
- Concentrations: 1% in physiological saline

A2. INDUCTION EXPOSURE (epidermal, second week)
- No. of exposures: one week after intradermal induction, 1 epidermal induction with test substance (patch: 2 x 4 cm, occlusive)
- Exposure period: 48 h
- Test groups: 0.4 g test substance in vaseline
- Control group: vehicle only
- Site: same site as intradermal induction (neck)
- Concentrations: 30% in vaseline
- Preparation: The application sites were pretreated the day before with 10% sodium lauryl sulfate.

B. CHALLENGE EXPOSURE (week 5)
- No. of exposures: 2 epidermal challenges (challenge and rechallenge) with test substance in vaseline and the vehicle alone (patch: 2 x 2 cm, occlusive)
- Exposure period: 24 h
- Test groups: vehicle alone and test article
- Control group: vehicle alone and test article
- Site: flank
- Concentrations: 10% in vaseline
- Evaluation (hr after challenge): 24 and 48 h after removal of the dressing
A second challenge (same procedure) was performed one week after the first challenge to confirm the results.

OTHER: body weight was recorded at the start and end of the test.

Positive control substance(s):

yes

Remarks:

Phenylendiame (strain is checked every 6 months)

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

20

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

20

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Reading:

rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Reading:

rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0%

No. with + reactions:

0

Total no. in group:

20

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0%

No. with + reactions:

0

Total no. in group:

20

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

0%

No. with + reactions:

0

Total no. in group:

20

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

0%

No. with + reactions:

0

Total no. in group:

20

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

5

Total no. in group:

20

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

10%

No. with + reactions:

5

Total no. in group:

20

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

9

Total no. in group:

20

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

10%

No. with + reactions:

9

Total no. in group:

20

Group:

positive control

Remarks on result:

not measured/tested

Results of test group after challenge and rechallenge treated with 10% of the test article

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

 

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

s = scaling

Body weight gain was in the normal range in all groups.

After challenge 25% of the animals showed positive results. After the rechallenge 45% of the animals showed positive results, indicating that the test substance has a sentitising potential.

Interpretation of results:

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

Conclusions:

25 % of the animals were sensitised after the standard challenge application. After a second challenge the sensitising potential of the test substance was confirmed; the incidence of positive animals increased to 45 %. As a result, the test article requires classification for skin sensitization according to CLP and DSD.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

In the key dermal sensitisation study with the test substance (no data on purity) in physiological saline 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 1% (in physiol. saline) and 30% (in vaseline) of the test substance, respectively. Epicutaneous challenge exposure (occlusive, 24 h) was performed with 10% (in vaseline) of the test substance. Phenylendiamine was used as positive control 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. In a rechallenge, performed one week later, 9/20 animals showed positive reactions corresponding to 45%. This is above the threshold of 30% laid down in Annex I of Regulation 1272/2008 and therefore the substance is considered a dermal sensitiser in this study (Ciba Geigy Ltd. 1990). 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, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for the purpose of classification under Regulation 1272/2008. Based on the criteria laid down in Regulation (EC) No. 1272/2008, classification as a skin sensitiser (category 1B) is warranted.