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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non GLP; non guideline; minor restrictions in design but adequate for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report date:
1979

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
not specified
GLP compliance:
no
Type of study:
guinea pig maximisation test

Test material

Constituent 1
Reference substance name:
2-ethylhexanoic acid
EC Number:
205-743-6
EC Name:
2-ethylhexanoic acid
Cas Number:
149-57-5
IUPAC Name:
2-ethylhexanoic acid

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
water
Challenge
Route:
epicutaneous, occlusive
Vehicle:
water
No. of animals per dose:
treated group: 10
control group: 5
Details on study design:
RANGE FINDING TESTS: 2 guinea pigs which were pre-treated with adjuvant only at the induction phase, test substance was applied at concentrations of 10, 5, 2 and 1%. A concentration of 2% was selected as the level to be used at the challenge stage.

MAIN STUDY
A. INDUCTION EXPOSURE
treated group: 3 injections: a) 0.1 ml Freund's adjuvant alone; b) 0.1 ml 2-ethylhexoic acid (1% w/w) alone; c) 0.05 ml 2-ethylhexoic acid (1% w/w) emulsified with 0.05 ml Freund's adjuvant; 6 days after the injection phase: treatment with sodium lauryl sulphate solution (10 % w/w), after 24 h: patch of Whatman No. 3 MM filter paper saturated with 2-ethylhexoic acid (5% w/w) covered by an overlapping patch of impermeable plastlc adhesive tape for48 h
control group: injection with Freund's adjuvant alone

B. CHALLENGE EXPOSURE
treated and control group: two weeks after the topical induction: 2-ethylhexoic acid (2% w/w) was applied on a 2 x 2 cm piece of filter paper to the test site of the guinea pig. The patch was held in place for the topical induction and removed 24 h Iater.

The degree of response was determined by trained assessors 24 h after removal of the challenge patch. Positive response are rated
according to the percentage of animals sensitised (Kligman).
Positive control substance(s):
no

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
48
Group:
test chemical
Dose level:
2% w/w
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no data
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2% w/w. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no data.
Reading:
1st reading
Hours after challenge:
48
Group:
negative control
Dose level:
2% w/w
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no data
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 2% w/w. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no data.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Under the conditions tested, the test substance is a non-sensitiser in guinea pigs.