Reaction Mass of (1R)-1-[(1S)-3,3-dimethylcyclohexyl]ethyl formate and (1R,2S)-2,6,6-trimethylcycloheptyl formate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Mar 1981 to 30 Apr 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The study pre-dates the adoption of the LLNA OECD 429 (2002).

Test material

Test material information

Constituent 1

Reference substance name:

α,3,3-trimethylcyclohexylmethyl acetate

EC Number:

246-737-3

EC Name:

α,3,3-trimethylcyclohexylmethyl acetate

Cas Number:

25225-10-9

Molecular formula:

C12H22O2

IUPAC Name:

1-(3,3-dimethylcyclohexyl)ethyl acetate

Test material form:

liquid

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

Animals were housed in suspended cages with wire mesh floors, with free access to tap water and Vitamin C-enriched Guiney-pig Diet Standard F.D.I. No 803189W. Hay was given once a week.
Animal room temperature was 21°C and the air exchange was maintained at 15 air changes/hour.
Lighting was controlled using a 12 hour light/dark cycle.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

paraffin oil

Concentration / amount:

10% v/v in liquid paraffin
10% v/v in a 50:50 mixture of Freund's adjuvant and liquid paraffin

Day(s)/duration:

Once

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Day(s)/duration:

4 hours

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

paraffin oil

Concentration / amount:

10% v/v in liquid paraffin
20% v/v in liquid paraffin

No. of animals per dose:

15 test animals and 15 control animals

Details on study design:

Induction
A 4x6 cm area of dorsal skin on the scapular region of the guiney-pig was clipped free of hair with electric clippers. Three pairs of intradermal injections were made simultaneously into this area. Injections were as follows: 1) Freund's complete adjuvant was diluted with an equal volume of water for injection; 2) The substance 10% v/v in liquid paraffin and; 3) The substance 10% in a 50:50 mixture of Freund's adjuvant and liquid paraffin.
Topical application was applied one week after the injections, the same 4x6 cm interscapular area was clipped and shaved free of hair. A 2x4 cm patch of Whatmen No 3 mm paper was saturated with the substance as supplied (100%). The patch was placed on the skin and covered by a length of impermeable plastic adhesive tape (5 cm width 'Blenderm'). This in turn was firmly secured by elastic adhesive bandage ('Elastoplast' of 5 cm width) wound around the torso of the animal and fixed with 'Sleek" impervious plastic adhesive tape. The dressing was left in place for 4h hours.
The control animals were treated similarly but with the exception that the substance was omitted from the intradermal injection and the topical application.

Challenge
Challenge applications were applied 2 weeks after last exposure using 20 and 10% in liquid paraffin. The challenge sites were evaluated 24, 48 and 72 hours 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

Dose level:

0.2 mL 20% v/v in liquid paraffin

No. with + reactions:

3

Total no. in group:

14

Clinical observations:

Localised dermal reaction (restricted to a small area)

Remarks on result:

other: One animal of the test group was found dead. See 'Any other information on results incl. tables'

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.2 mL 20% v/v in liquid paraffin

No. with + reactions:

3

Total no. in group:

14

Clinical observations:

Localised dermal reaction (restricted to a small area)

Remarks on result:

other: One animal of the test group was found dead. See 'Any other information on results incl. tables'

Results 3

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

0.2 mL 20% v/v in liquid paraffin

No. with + reactions:

0

Total no. in group:

14

Clinical observations:

dryness and sloughing of the epidermis

Remarks on result:

other: One animal of the test group was found dead. See 'Any other information on results incl. tables'

Results 4

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.2 mL liquid paraffin

No. with + reactions:

4

Total no. in group:

14

Clinical observations:

Localised dermal reaction (restricted to a small area)

Remarks on result:

other: One animal of the control group was killed. See 'Any other information on results incl. tables'

Results 5

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.2 mL liquid paraffin

No. with + reactions:

3

Total no. in group:

14

Clinical observations:

Localised dermal reaction (restricted to a small area)

Remarks on result:

other: One animal of the control group was killed. See 'Any other information on results incl. tables'

Results 6

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

negative control

Dose level:

0.2 mL liquid paraffin

No. with + reactions:

3

Total no. in group:

14

Clinical observations:

Localised dermal reaction (restricted to a small area) and one animal showed dryness and sloughing of the epidermis

Remarks on result:

other: One animal of the control group was killed. See 'Any other information on results incl. tables'

Results 7

Reading:

1st reading

Group:

positive control

Remarks on result:

other: no positive control was used

Any other information on results incl. tables

Mortality

One animal of the test group was found dead and one animal of the control group was killed. The mortality was not related to the substance.

Table 1. Number of animals with a skin reaction to a challenge with the substance

Animals	Skin reaction	Scores						Result
Scoring after (hours Challenge concentrations		24h 10%	24h 20%	48h 10%	48h 20%	72h 10%	72h 20%
Controls		7/14	4/14	6/14	3/14	5/14	3/14	-
Test animals	Reaction*	4/14	3/14	5/14	3/14	5/14	0/14	-

*Skin reaction mainly consisted of localised dermal reactions (restriction to small area of the challenge site)

Applicant's summary and conclusion

Interpretation of results:

other: no skin sensitiser

Remarks:

In accordance with EU CLP (EC no 1272/2008 and its amendments)

Conclusions:

The substance is not a skin sensitiser in the GPMT test (OECD TG 406).

Executive summary:

A GPMT was performed in accordance with OECD TG 406. Fifteen test and fifteen control animals were used. Dose levels for the induction phase were: intradermal 10% v/v in liquid paraffin and 10% v/v in a 50:50mixture of Freund's complete adjuvant and liquid paraffin, topical application as supplied and challenge application as 10% and 20% v/v in liquid paraffin. In the induction phase, the substance was applied to the dorsal skin on the scapular region (intradermal injection) or the interscapular area (topical application) of the guinea-pig clipped and shaved free of hair. Erythema and oedema were scored 24, 48 and 72 hours after the challenge. One animal of the test group was found dead and one animal of the control group was killed. The mortality was not related to the substance. As a consequence, 14 instead of 15 animals per group were scored. In the test animals and controls localised dermal reactions were seen, which were thought to be related to skin irritation rather than sensitisation because the number and frequency of the findings were similar in the treated groups and the test animals. In conclusion, the substance is not considered a sensitiser.