2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)-3H-pyrazol-3-one

Endpoint summary

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:

2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to guideline and GLP regulation

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Species:

guinea pig

Strain:

Himalayan

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Strain: Ibm: GOHI; SPF-quality guinea pigs (synonym: Himalayan spotted)
- Source: RCC Ltd, Biotechnology & Animal Breeding Division, Wölferstrasse 4, CH-4414 Füllinsdorf, Switzerland
- Age at study initiation: 4-6 weeks
- Weight at study initiation: 292 - 415 g
- Housing: Makrolon type-4 cages with standard softwood bedding
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22.5
- Humidity (%): 43-70
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Route:

epicutaneous, occlusive

Vehicle:

polyethylene glycol

Concentration / amount:

Induction: 25 %
Challenge: 25 %

Route:

epicutaneous, occlusive

Vehicle:

polyethylene glycol

Concentration / amount:

Induction: 25 %
Challenge: 25 %

No. of animals per dose:

Control: 10 females
test: 20 females

Details on study design:

RANGE FINDING TESTS:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Test groups: 1
- Control group: 1
- Site: dorsal skin
- Frequency of applications: 1/ week
- Duration: 3 weeks
- Concentrations: 25 %

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: no data
- Exposure period: no data
- Test groups: 1
- Control group: 1
- Site: dorsal skin (different site)
- Concentrations: 25 %
- Evaluation (hr after challenge): 24 & 48 h

Positive control substance(s):

yes

Remarks:

Mercaptobenzthiazole

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on a non-adjuvant sensitization test in guinea pigs and in accordance to Commission Directive 96/54/EEC, the test item, applied at a
concentration of 25 % in PEG 300, has not to be classified and labelled as a skin sensitizer.

Executive summary:

The purpose of this skin sensitizing study was to assess the possible allergenic potential of the test item when administered topically to albino guinea pigs. For this purpose the "Buhler Test" modified by Ritz, H.L. and Buhler, E.V. (1980) was used.

Twenty female animals of the test group were treated topically with the test item at 25 % in PEG 300 once a week for a 3 week induction phase.

Two weeks after the final induction application the animals were challenged with the same test item concentration of 25 % in PEG 300 as used for induction.

The ten animals of the control group were not treated during the induction. They were treated once at challenge with the test item at 25% in PEG 300.

Results

None of the control and test animals showed skin reactions after the challenge treatment with the tested concentration of the test item at 25% in PEG 300.

Based on this non-adjuvant sensitization test in guinea pigs and in accordance to Commission Directive 96/54/EEC, the test item, applied at a concentration of 25 % in PEG 300, has not to be classified and labelled as a skin sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In a Bühler Assay not skin sensitisation potential was detected

Migrated from Short description of key information:
In a Bühler Assay not skin sensitisation potential was detected

Justification for selection of skin sensitisation endpoint:
Only available study

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

In a Bühler Assay not skin sensitisation potential was detected

Justification for classification or non-classification

not classified

In a Bühler Assay not skin sensitisation potential was detected.