4'-hydroxyacetophenone

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation, other

Remarks:

in vivo test already available

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: well-documented GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4100 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Remarks:

testing lab.

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

4'-hydroxyacetophenone

EC Number:

202-802-8

EC Name:

4'-hydroxyacetophenone

Cas Number:

99-93-4

Molecular formula:

C8H8O2

IUPAC Name:

1-(4-hydroxyphenyl)ethan-1-one

Details on test material:

Name of the test substance used in the study report: C-01650 (4-HAP)

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals and environmental conditions:

Weight at study initiation: 300-500 grams, at time of dosing
Acclimation period: at least 7 days
Animal identification: Each animal was assigned an unique and individual number. This number was permanently indicated on the animal with a tar tag.
They were housed individually in stainless steel, wire mesh bottom cages (temperature: 64 - 79°F, humidity: 40 - 70%, light/dark rhythm: 12/12).
Fresh guinea Pig feed was provided ad libitium throughout both the acclimation and study periods; water was provided ad libitum.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

other: propylene glycol

Induction 2

Concentration / amount:

Intradermal range finding phase: 5, 4, 2 and 1% of the test article
Topical range finding phase: 75, 50, 25 and 10% of the test article
Challenge: 0.5 g of a 75% mixture

Challenge

Challenge 1

Route:

intradermal

Vehicle:

other: propylene glycol

Challenge 2

Concentration / amount:

Intradermal range finding phase: 5, 4, 2 and 1% of the test article
Topical range finding phase: 75, 50, 25 and 10% of the test article
Challenge: 0.5 g of a 75% mixture

No. of animals per dose:

total: 50

Details on study design:

Intradermal injection (as a 5% solution in propylene glycol with and without Freund's adjuvant) and then by topical application (5% in propylene glycol) eight days later.
Two weeks after the second induction, animals were challenged with 0.5 g of test material as a 75% preparation in petrolatum using a 24-h dermal exposure.
Intradermal Range Finding Study: Four w/v dilutions of the test artiele were prepared in propylene glycol and administered to each of five guines pigs. The dilutions used were 5%, 4%, 2%, and 1 %. Each dilution was intradermally injected at a volume of 0.1 ml. Two injections on each side of the dorsal midline were made above the scapular region.
Approximately 24 and 48 hours after dosing, all sites were scored for erythema and edema according to the Draize scoring.
Topical Range Finding Study: Four w/w dilutions of the test article were prepared in petrolatum and administered to each of five guinea pigs. The concentrations used were: 75%, 50%, 25%, and 10%. A dose of 0.5 gram of each concentration of the test article was applied to a one square inch gauze patch which was then placed on the skin of the flank region. Two patches wert placed on each side of the dorsal midline. The patches were taped in place and the trunk of the animal was wrapped with a non-reactive, occlusive wrapping.
Approximately 24 hours following patch application, all wrappings were removed and the skin wiped to remove any remaining lest article.
Approximately 24 and 48 hours after patch removal, all sites were scored for erythema and edema according to the Draize scoring method. From these readings, the highest non-irritating dose level was selected for the challenge phase of the study.

Positive control substance(s):

yes

Results and discussion

In vivo (non-LLNA)

Results

Reading:

other: challenge

Hours after challenge:

24

Group:

test chemical

Dose level:

75% of a mixture

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: other: challenge. . Hours after challenge: 24.0. Group: test group. Dose level: 75% of a mixture. No with. + reactions: 0.0. Total no. in groups: 20.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Under the conditions of this test, 4-HAP, CAS# 99-93-4) is considered to be a non-sensitizer (0% sensitized) and the positive control, DNCB, is considered to be an extreme sensitizer (100% sensitized).