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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
The study was conducted in 1978.
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report date:
1978

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Induction: Days 0 – 20.
On Day 0, 0.1 mL of the test material undiluted and at progressively diluted solutions were applied to an area measuring 8 cm2 on the clipped flank skin of four guinea pigs per concentration group.
The applications were repeated daily for three weeks, or done five times weekly during four weeks, always using the same skin site. The application site was left uncovered.

Challenge: Days 21 – 35.
To determine whether or not contact sensitisation was induced, all the groups of guinea pigs previously treated for 21 days with the vehicle pre-treated as above, as well as six to eight untreated or only with vehicle pre-treated controls were tested on days 21 and 35 on the contralateral flank with the test material at the minimal irritating and some lower concentrations. The minimal irritating concentration was used in order to confirm biological activity determined before starting the induction (Day -1) and to exclude dales results based on instability of test materials. These tests were performed by applying with a pipette 0.025 mL of each concentration to skin areas measuring 2 cm2, the reactions being read after 24, 48 and / or 72 hours. This procedure enables the determination of the minimal sensitising concentration necessary for inducing allergic contact hyper-sensitivity and the minimal eliciting concentration necessary to cause a positive reaction.
The test material is considered allergenic at a concentration when at least one of the eight animals of the concentration group concerned shows positive reactions with non-irritant concentrations used for challenge, i.d. its threshold concentration causing skin reactions is shifted into the lower part of the concentration range used to challenge.
GLP compliance:
no
Remarks:
Study pre-dates GLP.
Type of study:
open epicutaneous test
Justification for non-LLNA method:
The study pre-dates the LLNA method.

Test material

Constituent 1
Chemical structure
Reference substance name:
1,2,3,4,4a,7,8,8a-octahydro-2,4a,5,8a-tetramethyl-1-naphthyl formate
EC Number:
265-742-1
EC Name:
1,2,3,4,4a,7,8,8a-octahydro-2,4a,5,8a-tetramethyl-1-naphthyl formate
Cas Number:
65405-72-3
Molecular formula:
C15H24O2
IUPAC Name:
1,2,3,4,4a,7,8,8a-octahydro-2,4a,5,8a-tetramethyl-1-naphthyl formate
Test material form:
liquid

In vivo test system

Test animals

Species:
guinea pig
Strain:
not specified
Sex:
not specified
Details on test animals and environmental conditions:
No data

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, open
Vehicle:
other: Acetone
Concentration / amount:
3, 10, 30 and 100 %
Challengeopen allclose all
Route:
epicutaneous, open
Vehicle:
other: Acetone
Concentration / amount:
3, 10, 30 and 100 %
No. of animals per dose:
4 animals / dose
Details on study design:
Induction: Days 0 – 20.
On Day 0.1 mL of the test material undiluted and at progressively diluted solutions were applied to an area measuring 8 cm2 on the clipped flank skin of four guinea pigs per concentration group.
The applications were repeated daily for three weeks, or done five times weekly during four weeks, always using the same skin site. The application site was left uncovered.

Challenge: Days 21 – 35.
To determine whether or not contact sensitisation was induced, all the groups of guinea pigs previously treated for 21 days with the vehicle pre-treated as above, as well as six to eight untreated or only with vehicle pre-treated controls were tested on days 21 and 35 on the contralateral flank with the test material at the minimal irritating and some lower concentrations. The minimal irritating concentration was used in order to confirm biological activity determined before starting the induction (Day -1) and to exclude dales results based on instability of test materials. These tests were performed by applying with a pipette 0.025 mL of each concentration to skin areas measuring 2 cm2, the reactions being read after 24, 48 and / or 72 hours. This procedure enables the determination of the minimal sensitising concentration necessary for inducing allergic contact hyper-sensitivity and the minimal eliciting concentration necessary to cause a positive reaction.
The test material is considered allergenic at a concentration when at least one of the eight animals of the concentration group concerned shows positive reactions with non-irritant concentrations used for challenge, i.d. its threshold concentration causing skin reactions is shifted into the lower part of the concentration range used to challenge.

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
4
Remarks on result:
other: 1st reading. The challenge time was 24 Hours after the 3 week (504 hours) induction phase.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
100%
No. with + reactions:
0
Total no. in group:
6
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0%
No. with + reactions:
0
Total no. in group:
0
Clinical observations:
NA

Any other information on results incl. tables

Capacity to cause allergic sensitisation

After daily applications over three weeks

Concentration %

Sensitisation rate

Number of animals positive / total

Day 21

Day 35

100

0 / 4

0 / 4

30

0 / 4

0 / 4

10

0 / 4

0 / 4

3

0 / 4

0 / 4

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The preparation does not sensitise the guinea pig in the OET.
Executive summary:

The test substance was assessed for skin sensitisation potential using an open epicutaneous test on guinea pigs. The test substance was not sensitising under the conditions of the test.

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