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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Principles of study comparable to those of OECD TG 406, however, non-standard grading, non-GLP

Data source

Reference
Reference Type:
publication
Title:
The sensitization potential of some perfume ingredients tested using a modified Draize procedure
Author:
Sharp DW
Year:
1978
Bibliographic source:
Toxicology 9, 261-271

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
GLP compliance:
no
Type of study:
Draize test

Test material

Constituent 1
Chemical structure
Reference substance name:
4'-methylacetophenone
EC Number:
204-514-8
EC Name:
4'-methylacetophenone
Cas Number:
122-00-9
Molecular formula:
C9H10O
IUPAC Name:
1-(4-methylphenyl)ethanone
Details on test material:
No details, except that substance came from commercial batch and had passed quality control checks for odour

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: in-house colony
- Age at study initiation: no data
- Weight at study initiation: ca 350 g
- Housing: pairs of the same sex in wire mesh cages
- Diet (e.g. ad libitum): pelleted guinea pig diet, cabbage, hay
- Water (e.g. ad libitum): water ad libitum
- Acclimation period: not reported

ENVIRONMENTAL CONDITIONS
- not reported

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal
Vehicle:
no data
Concentration / amount:
Intradermal induction concentration: 0.5%
Intradermal challenge concentration: 0.2%
Epicutaneous challenge concentration: 20%
Challengeopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
no data
Concentration / amount:
Intradermal induction concentration: 0.5%
Intradermal challenge concentration: 0.2%
Epicutaneous challenge concentration: 20%
No. of animals per dose:
10 animals (either 4 females, 6 males or vice versa)
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: one intradermal injection at 4 sites
- Exposure period: 14 days
- Test groups: single test group of 10 animals
- Control group: none
- Site: 4 sites overlying the 2 auxillary and 2 inguinal lymph nodes
- Frequency of applications: one
- Duration: 14 days
- Concentrations: 0.5% in 0.1 mL aliquots

B. CHALLENGE EXPOSURE
- No. of exposures: 2
- Day(s) of challenge: 14 days after induction
- Exposure period: One challenge as intradermal injection; for topical application not known, but probably no removal
- Test groups: single test group of 10 animals
- Control group: second challenge included control group
- Site: intradermal challenge in one flank and topcal challenge in the other
- Concentrations: 0.2% in 0.1 mL aliquots intradermally; 20% in 0.1 mL aliquots topically
- Evaluation (hr after challenge): first evaluation 24 hours after challenge; 7 days later second challenge with controls
Challenge controls:
Four previously untreated animals of the same sex and similar weight to the test animals were treated intradermally and topically on opposite flanks with 0.1 mL aliquots of test substances at 0.2% and 20%, respectively.
Positive control substance(s):
no

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
0.2% intradermally
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None reported
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.2% intradermally. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None reported.
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
20% topically
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None reported
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 20% topically. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None reported.
Reading:
rechallenge
Hours after challenge:
168
Group:
test chemical
Dose level:
0.2% intradermally
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None reported
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 168.0. Group: test group. Dose level: 0.2% intradermally. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None reported.
Reading:
rechallenge
Hours after challenge:
168
Group:
test chemical
Dose level:
20% topically
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None reported
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 168.0. Group: test group. Dose level: 20% topically. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None reported.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: expert judgment
Conclusions:
The substance was found to be non-sensitising in a modified Draize sensitisation test performed in guinea pigs.
Executive summary:

The skin sensitisation potential of the test substance 4'-methylacetophenone was tested in guinea pigs in a modified Draize sensitisation test under non-GLP conditions. Groups of ten animals, about 350 g at the start of testing, were used in each test. Aliquots of test substance at 0.5% in solution were injected intradermally at 4 sites which overlie the 2 auxillary and 2 inguinal lymph nodes. Fourteen days later each animal was challenged intradermally in one flank and topically in the other with 0.1 mL aliquots of test substance at the level of 0.2% and 20%, respectively. After 24 hours, the skin reactions were scored and in case of no evident sensitisation the induction and challenge procedure was repeated. A confirmatory challenge with controls was included irrespective of any apparent sensitisation reactions at the previous challenge.

The test substance 4'-methylacetophenone was considered as non-sensitising to the skin in this modified Draize sensitisation test.