Benzene, C20-24 (even numbered) sec-alkyl derivs.

Skin sensitisation

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:

weight of evidence

Study period:

Oct. 4, 1983-Nov. 6, 1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well-documented study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1992

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The guinea pig maximization test was performed prior to publication of the OECD guideline 429.

Test material

Test material information

Constituent 1

Reference substance name:

Benzene C10-13 alkyl derivs.

IUPAC Name:

Benzene C10-13 alkyl derivs.

Constituent 2

Reference substance name:

Benzene, C10-13-alkyl derivs.

EC Number:

267-051-0

EC Name:

Benzene, C10-13-alkyl derivs.

Cas Number:

67774-74-7

Molecular formula:

C6 H5 Cn H2n+1; n= 10 to 13

IUPAC Name:

Benzene, C10-C13 Alkyl derivs.

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: albino

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: F. Winkelmann
- Weight at study initiation: 319 g
- Housing: 1-5 animals in Makrolon type IV cages, idenitified by marking fur with dye
- Diet (e.g. ad libitum): G4 Alleindiat fur Meerschweinchen, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 4-8 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/-1 degree C
- Humidity (%): 60 +/- 5%
- Air changes (per hr): 15 per hr
- Photoperiod (hrs dark / hrs light): 12 hrs light/12 hrs dark


IN-LIFE DATES: From: Oct. 4, 1983 To: Nov. 6, 1983

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

paraffin oil

Induction 2

Concentration / amount:

0.1 ml 20% and 40%

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

paraffin oil

Challenge 2

Concentration / amount:

0.1 ml 20% and 40%

No. of animals per dose:

20 animals total

Details on study design:

In the induction phase, test guinea pigs received three pairs of intradermal injections simultaneously. The paired injections were, (1) 0.1 ml Freunds complete adjuvant (FCA), (2) 0.1 ml 20% test substance in paraffin oil, (3) 0.1 ml 40% test substance in FCA. One week later, 2 X 4 cm filter papers soaked with 50% test substance in paraffin oil were applied to the same area of the shoulders and then held in place with occlusive dressing for 48 hours. This application was followed by topical challenge about 14 days later in which the left flanks of test animals were exposed to 2 X 4 cm filter papers soaked with 20% substance in paraffin oil, held in place with occlusive wrapping. A second topical challenge was also performed about one week later, in which the right flanks of the test animals were exposed to 2 X 2 cm filter paper strips soaked with 5% and 10% test substance in paraffin oil, held in place for 24 hours with an occlusive wrapping. Observations of skin reactions indicative of irritation or sensitization at each challenge were conducted at 24, 48 and 72 hours following the removal of occlusive wrappings.

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5, 10, and 20% test substance

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 5, 10, and 20% test substance. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. No with. + reactions: 0.0. Total no. in groups: 20.0.

Any other information on results incl. tables

Skin sensitization results at 48 hrs

Animal	20% Left flank	20% Left flank	5% Right flank back	10% Right flank front	5% Right flank front	10% Right flank back
1	0	0	0	0	0	0
2	1*	1*	0*	0 (F)	0	0
3	1	0	0*	0* (O)	0	0
4	0	0	0	0	0	0
5	1*	0	0	0	0	0
6	0	0	0	0	0	0*
7	1	0	0	0*	0	0
8	0*	1*	0*	0*	0*	0*
9	0	0*	0	0	0	0
10	0	1*	0	0	0	0
11	0	0	0	0	0 (C)	0 (C)
12	1	1*	0	0	0*	0*
13	1	1	0	0	0*	0*
14	1*	1*	0	0*	0*	0*
15	0	0	0	0	0	0
16	1	1*	0	0	0	0
17	1*	1*	0*	0	0	0
18	1	1	0	0	0	0
19	1*	1*	0	0	0	0
20	0	0	0	0	0	0*

* - Dryness

C - Scratches

F - Redness

O – Hardening

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test substance is not sensitizing to skin.

Executive summary:

This study examined the potential of the test substance to cause sensitization to skin. Groups of 20 female guinea pigs were exposed by injection to 20 and 40% test substance. One week later, they were exposed dermally to a solution of 50% test substance. The first challenge was 14 days later, and the animals were exposed to 20% test substance dermally. One week later, a second challenge was done, in which the animals were exposed to 5 and 10% test substance dermally. Animals were scored for skin irritation at 24, 48, and 72 hrs after the last challenge. The 48 hr reading was used to determine sensitization. No signs of dermal irritation were seen at this reading. The test substance in not sensitizing to skin.