Dimethyl isophthalate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation

Remarks:

in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Reliable scientific study from a reputable laboratory.

Data source

Reference

Reference Type:

publication

Title:

Comparison of the local lymph node assay with the guinea-pig maximization test for the detection of a range of contact allergens

Author:

Basketter DA and Scholes EW

Year:

1992

Bibliographic source:

Food Chem. Toxic. 30(1): 65-69

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Principles of method if other than guideline:

GPMT and LLNA validation study

GLP compliance:

no

Type of study:

other: Guinea Pig Maximization test and murine local lymph node assay

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl isophthalate

EC Number:

215-951-9

EC Name:

Dimethyl isophthalate

Cas Number:

1459-93-4

Molecular formula:

C10H10O4

IUPAC Name:

1,3-dimethyl benzene-1,3-dicarboxylate

Test material form:

not specified

Details on test material:

source: BP (Guildford, surrey, UK), at least 98% pure.

In vivo test system

Test animals

Species:

other: guinea pig and mouse

Strain:

other: Albino dunkin-Hartley guinea pig and CBA/Ca mice

Sex:

male/female

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: A/P (acetone: polyethylene glycol 400 (70:30, v/v)).

Challenge

Route:

epicutaneous, occlusive

Vehicle:

other: A/P (acetone: polyethylene glycol 400 (70:30, v/v)).

No. of animals per dose:

4

Details on study design:

The Magnusson and Kligman guinea-pig maximization test. The test method carried out is based on and similar to that described by Magnusson and Kligman (1970). Albino Dunkin—Hartley guinea-pigs weighed approximately 350 g at the start of the study. Preliminary irritation tests were carried out to determine the concentrations of the test substances suitable for induction of sensitization and for sensitization challenge. Guinea-pigs were then treated by a series of six intradermal injections in the shoulder region to induce sensitization. After 6-8 days, sensitization was boosted by a 48-hr occluded patch placed over the injection site. 12-14 days later, the animals were challenged on one flank by a 24-hr occluded patch at the maximum non-irritant concentration. Challenge sites were scored for erythema (scale 0-3) and oedema 24 and 48 hr after removal of the patches.

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

No. with + reactions:

0

Clinical observations:

evaluated as negative in the GPMT

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. No with. + reactions: 0.0. Clinical observations: evaluated as negative in the GPMT.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

No. with + reactions:

0

Clinical observations:

evaluated as negative in the GPMT

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. No with. + reactions: 0.0. Clinical observations: evaluated as negative in the GPMT.

Any other information on results incl. tables

In the GMPT assay, DMIP had a 0% response and was classified as a non-sensitizer.

In the LLNA assay, DMIP had a "test to control lymphocyte proliferation index" (dpm/node) of 1.0, and was classified as a non-sensitizer.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Dimethyl isophthalate (DMIP) was part of a series of chemicals tested to validate the murine local lymph node assay (LLNA), by testing in both the guinea pig maximization test (GPMT) and the LLNA. In both studies, DMIP was inactive, and was evaluated as non-sensitizing. The substance is not classified as a dermal sensitizer according to Regulation EC No. 1272/2008.