Reaction mass of 1,3-diisopropylbenzene and 1,4-diisopropylbenzene

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

no

Type of study:

Buehler test

Justification for non-LLNA method:

study performed in 1984, before the validation of the LLNA method

Test material

Test material information

Constituent 1

Reference substance name:

1,4-diisopropylbenzene

EC Number:

202-826-9

EC Name:

1,4-diisopropylbenzene

Cas Number:

100-18-5

Molecular formula:

C12H18

IUPAC Name:

1,4-diisopropylbenzene

Test material form:

liquid: viscous

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

not specified

Study design: in vivo (non-LLNA)

Induction

Route:

epicutaneous, occlusive

Vehicle:

other: acetone/dioxane/guinea pig fat (7:2:1)

Concentration / amount:

10% w/v in FCA

Challenge

Route:

intradermal

Vehicle:

other: acetone/dioxane/guinea pig fat (7:2:1)

Concentration / amount:

10% w/v in FCA

Details on study design:

The Kodak methods employed both a) topical application of the test material in a unique solvent designed to enhance penetration and dermal absorption and b) subcutaneous injection of the material into the foot pad of the test guinea pigs. The solvent that was used was prepared in the laboratory and consisted of 70% acetone, 20% dioxane, and 10% guinea pig fat. The skin was also depilated prior to application to enhance contact and absorption. To stimulate the immune system, Freund’s Complete Adjuvant was injected into the guinea pig footpad.

Positive control substance(s):

not specified

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Remarks on result:

not measured/tested

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Remarks on result:

not measured/tested

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based upon the results of this study, p-diisopropylbenzene is not a dermal sensitizer in guinea pigs

Executive summary:

In a Kodak standard dermal sensitization assay that is similar to the Buehler method, both topical and subcutaneous injections of test materials suspended or dissolved in agents known to stimulate the immune system. The Kodak method utilized ten guinea pigs that were treated by both a) topical application of the test material in a unique solvent designed to enhance penetration and dermal absorption and b) subcutaneous injection of the material into the foot pad of the test guinea pigs. The solvent that was used was prepared in the laboratory and consisted of 70% acetone, 20% dioxane, and 10% guinea pig fat. The skin was also depilated prior to application to enhance contact and absorption. To stimulate the immune system upon challenge, the test material was incorporated into Freund's Complete Adjuvant and was injected into the footpad of test animals. Following induction, animals were subjected to challenge with the test material that was evaluated 24 hours after exposure, wherein none of the test animals displayed evidence of dermal sensititization.