Bis(2-ethylhexyl) phthalate

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:

other: Comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

lack of data on materials (purity), no positive control

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

old test (1981) LLNA methodology not available that times

Test material

Test material information

Constituent 1

Reference substance name:

Bis(2-ethylhexyl) phthalate

EC Number:

204-211-0

EC Name:

Bis(2-ethylhexyl) phthalate

Cas Number:

117-81-7

Molecular formula:

C24H38O4

IUPAC Name:

1,2-bis(2-ethylhexyl) benzene-1,2-dicarboxylate

Details on test material:

DEHP
Name: Vestinol AH as supplied by the sponsor
Purity: not indicated
Physical state: clear colourless liquid
Storage: in its original container under ambient conditions

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Porcellus Animal Limited
- Age at study initiation: no data
- Weight at study initiation: 300-400g
- Housing: 5/cage
- Diet (e.g. ad libitum): ad libitum BP Nutrition FD1 Diet (a supplement of hay was given)
- Water (e.g. ad libitum): ad libitum water
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 (17-22.5)
- Humidity (%): 52 (38-64)
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

paraffin oil

Induction 2

Concentration / amount:

intradermal induction: 10%
cutaneous induction: 50%
challenge phase: 50%

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

paraffin oil

Challenge 2

Concentration / amount:

intradermal induction: 10%
cutaneous induction: 50%
challenge phase: 50%

No. of animals per dose:

total of 32 female guinea pigs (20 in the test group and 10 in the control group, 2 were used for the preliminary test)

Details on study design:

RANGE FINDING TESTS:
Before challenging the test animals a maximum non-irritant concentration of the test material was determined in preliminary experiments on 2 of the 12 guinea pigs, which were pre-treated with 2 injections of Freund's adjuvant at the injection phase.
The test material was applied in a series of concentrations in paraffin oil to the shaved flanks of the guinea pigs, under the same occlusive patch system used for the topical induction. It was tested in this way at concentrations of 50%, 20%, 10% and 5% (v/v).

There were no positive responses and a concentration of 50% was selected as the challenge concentration.

MAIN TEST
The induction procedure consisted of an intradermal injection of the test material into the skin of the shoulder region followed by a topical application 7 days later.
The intradermal injection (actually 3 injections) consisted of 0.1 ml Freund’s adjuvant alone, 0.1 ml 10% DEHP in paraffin oil, and 0.05 ml 10% DEHP in paraffin oil emulsified with 0.05 ml Freund’s adjuvant.
The control group received 2 injections of Freund’s adjuvant only.

For the topical application, a 2x2 cm patch of filter paper was wetted with 50% DEHP in paraffin oil and applied for 48 hours to the pre-treated area. The control group was not subjected to topical application.

The challenge procedure, which consisted of a topical application, was carried out 14 days after the completion of the induction period. In preliminary experiments, a solution of 50% DEHP was determined to be non-irritant; higher concentrations were not tested. A 2x2 cm patch wetted with 50% DEHP was applied to a challenge site (on the right flank) of all animals for 24 hours. The degree of response was assessed 24 hours after removal of the challenge patch and rated.

Any animal showing erythema at the challenge site was considered to have shown a positive response.

Challenge controls:

No

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:

50%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Any other information on results incl. tables

DEHP was unequivocally not sensitising in the guinea pig maximization test; there were no positive responses.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Executive summary:

One Magnusson-Kligman guinea pig maximization test has been performed, in which female albino Dunkin-Hartley guinea pigs were used. The maximisation test comprised two procedures. The induction procedure consisted of an intradermal injection of the test material into the skin of the shoulder region followed by a topical application 7 days later. The intradermal injection (actually 3 injections) consisted of 0.1 ml Freund’s adjuvant alone, 0.1 ml 10% DEHP in paraffin oil, and 0.05 ml 10% DEHP in paraffin oil emulsified with 0.05 ml Freund’s adjuvant. The control group received 2 injections of Freund’s adjuvant only. For the topical application, a 2 . 2 cm patch of filter paper was wetted with 50% DEHP in paraffin oil and applied for 48 hours to the pre-treated area. The control group was not subjected to topical application. The challenge procedure which consisted of a topical application was carried out 14 days after the completion of the induction period. In preliminary experiments, a solution of 50% DEHP was determined to be non-irritant; higher concentrations were not tested. A 2 . 2 cm patch wetted with 50% DEHP was applied to a challenge site (on the right flank) of all animals for 24 hours. The degree of response was assessed 24 hours after removal of the challenge patch and rated. Any animal showing erythema at the challenge site was considered to have shown a positive response. DEHP was unequivocally not sensitising in the guinea pig maximization test; there were no positive responses.