p-phenylenediamine

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: well performed study in compliance with elementary guideline requirements

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 D. A. and SCHOLES E. W.

Year:

1992

Bibliographic source:

Food and chemical toxicology, Vol 30, 65-69

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: Basketter et al., 1991 and OECD 429

Deviations:

yes

Remarks:

method prior to OECD guideline

Principles of method if other than guideline:

CBA/Ca mice were used at the age of 8-12 wk. Animals of both sexes were used, but single experiments were limited to one sex. The test substance was assayed at three consecutive concentrations from the following range: 100, 50, 25, 10, 5, 2.5, 1.0, 0.5, 0.25, 0.1, 0.05 and 0.01%. Groups of four mice were treated by a daily topical application of 25 µl of each concentration on the dorsal surface of each ear for 3 consecutive days. Control mice were treated with the vehicle alone. 4-5 days after the first topical application, all mice were injected intravenously through the tail vein with 250 µl phosphate buffered saline (PBS) containing [3H]methyl thymidine (3HTdR; 20 µCi). After 5 h the mice were killed by carbon dioxide asphyxiation, and the draining auricular lymph nodes were excised and pooled for each experimental group. A single-cell suspension of lymph node cells (LNC) was prepared by gentle mechanical disaggregation through a stainless-steel gauze (200-mesh size), using the plunger of a syringe. Pooled LNC were pelleted at 190 g for 10 min, washed twice with 10 ml PBS and resuspended in 3 ml trichloroacetic acid (TCA; 5%) for the precipitation of macromolecules. After an overnight incubation with TCA at 4°C, the precipitate was recovered by centrifugation, resuspended in 1 ml TCA and transferred to 10 ml scintillation fluid. 3HTdR incorporation was measured by β-scintillation counting. The proliferative response of LNC was expressed as radioactive disintegrations per min per lymph node (dpm/node), and as the ratio of 3HTdR incorporation into LNC of test nodes relative to that recorded for control nodes (test/control ratio). A chemical was regarded as a sensitizer in the LLNA if at least one concentration of the chemical resulted in a three-fold or greater increase in 3HTdR incorporation compared with control values. Also, the data had to be compatible with a biological dose response although an allowance was made, especially at high doses, for either local toxicity or immunological suppression.

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

p-phenylenediamine

EC Number:

203-404-7

EC Name:

p-phenylenediamine

Cas Number:

106-50-3

Molecular formula:

C6H8N2

IUPAC Name:

benzene-1,4-diamine

Details on test material:

Several substances were tested in this study, the vast majority of these compounds were more than 98% pure.

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/Ca

Sex:

male/female

Details on test animals and environmental conditions:

CBA/Ca mice were used at the age of 8-12 wk. Animals of both sexes were used, but single experiments were limited to one sex.

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

2.5, 5, 10%

No. of animals per dose:

4

Details on study design:

Exposure period: 4 d

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

T/C ratio (ratio of test to control lymphocyte proliferation) of Cinnamic aldehyde
5%: 12.5
10%: 18.4
25%: 15.4

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: T/C ratio (ratio of test to control lymphocyte proliferation) of p-Phenylene diamine 2.5%: 12.8 5%: 16.5 10%: 23.3

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: DPM data are not presented in the publication.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

p-Phenylene diamine was considered to be a skin sensitiser under the conditions of this test.

Executive summary:

A sample of p-Phenylene diamine was assessed for its skin sensitisation potential using the mouse Local Lymph Node Assay. The test sample was applied as 2.5, 5.0, 10.0 % preparations in acetone-olive oil (4:1, v/v).

p-Phenylene diamine was shown to have the capacity to cause skin sensitisation when apllied as 2.5, 5.0, 10.0 % preparations.

In a positive control study, hexylcinnamaldehyd was shown to have the capacity to cause skin sensitisation, confirming the validity of the protocol used in this study.

In conclusion, p-Phenylene diamine was considered to be a skin sensitiser under the conditions of this test.