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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:
weight of evidence
Study period:
01 Feb - 03 Apr 1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The results of the reliability check were inconclusive.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report date:
1995

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Remarks:
results of reliability check were inconclusive
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
yes
Remarks:
results of reliability check were inconclusive
GLP compliance:
yes
Type of study:
Buehler test
Justification for non-LLNA method:
Test was done before LLNA as first-choice method for in-vivo testing was set into force.

Test material

Constituent 1
Chemical structure
Reference substance name:
(Z)-octadec-9-enyl (Z)-docos-13-enoate
EC Number:
241-654-9
EC Name:
(Z)-octadec-9-enyl (Z)-docos-13-enoate
Cas Number:
17673-56-2
Molecular formula:
C40H76O2
IUPAC Name:
octadec-9-en-1-yl docos-13-enoate

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Dunkin Hartley Crl:(HA)BR
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River, Kisslegg, Germany
- Age at study initiation: approximately 5 weeks
- Weight at study initiation: approximately 380 g
- Housing: in groups of 2-3 animals in Makrolon Type IV cages (EBECO) with standard softwood bedding (ARWI-Center, Essen, Germany); bedding chaged twice weekly
- Diet: pelleted Altromin Maintenance Diet 3022 (Fa. Altromin, Lage, Germany), ad libitum. Carrots optionally added.
- Water: tap water, ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 45-70
- Air changes (per hr): 100 m³
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: 7 Feb - 3 Apr 1995

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, occlusive
Vehicle:
peanut oil
Concentration / amount:
70 %
Challenge
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
peanut oil
Concentration / amount:
60%
No. of animals per dose:
10 (control group), 20 (treatment group)
Details on study design:
RANGE FINDING TESTS:
Irritation test: 0.5 mL of the test substance was applied topically to the shaved skin of 3 guinea pigs, successively. A concentration of 12.5, 25, 50 and 100% was applied to the left flank and 30, 50 and 70% concentration to the right flank. The exposure was terminated after 6 hours by removing the plaster and cleaning the skin with 20% propylene glycol. The severity of erythema and oedema was assessed 24 and 48 h after exposure. The undiluted substance caused weak, confluent erythema in 1/3 animals at the 24 and 48 hour reading time point. The 70% solution was the lowest concentration to induce minimal irritation; causing weak, confluent erythema in 1/3 animals 24 hours after exposure. This effect had cleared within 48 hours.
Challenge test: the maximum non-irritating concentration was tested one week before the challenge in the main study by applying 0.5 mL of 30, 50 and 70% solution to the right flank of 5 animals in the control group under occlusive conditions. After 6 hours, the plaster was removed and the site cleaned with 20% propylene glycol. 24 and 48 hours after the exposure ended, the skin irritating effects were assessed. None of the concentrations caused skin irritation. 60% was selected to be the challenge dose.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 h
- Test groups: test substance in peanut oil
- Control group: peanut oil
- Site: left cranial shaved flanks
- Frequency of applications: once weekly
- Duration: Day 1-14
- Concentrations: 70%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 28
- Exposure period: 6 h
- Test groups: test substance in peanut oil
- Control group: test substance in peanut oil
- Site: left and right caudal flanks
- Concentrations: 60%
- Evaluation (hr after challenge): 24, 48 and 72 h
Positive control substance(s):
no

Results and discussion

Positive control results:
A reliability check is carried out at regular intervals with alpha-hexyl cinnamic aldehyde to check the sensitivity of the test system and the reliability of the experimental methods used by the test laboratory. An independent study was performed in October-December 1994 (report No. R 9400844), according to the Buehler method. During the first challenge with 25% alpha-hexyl cinnamic aldehyde, a sensitisation reaction was induced in 25% (5/20) of the Dunkin Hartley guinea pigs, while the second challenge did not lead to conclusive sensitisation reactions. In the negative control group, the first challenge induced sensitisation in 20% (2/10) of the animals, and the second challenge did not caused any sensitisation reactions. The 50% solution in peanut oil that was used for the topical inductions, caused weak to moderate skin irritation. A 25% solution was applied in the first challenge, while a 25% solution was applied to the left flank and 15, 20 and 25% solutions were applied to the right flank during the second challenge. As 20% of the animals in the negative control group reacted, the results of the reliability check are inconclusive.

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
Induction: 70%, Challenge: 60%
No. with + reactions:
1
Total no. in group:
10
Clinical observations:
1/10 animals showed slight, patchy erythema on the right flank only
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
Induction: 70%, Challenge: 60%
No. with + reactions:
0
Total no. in group:
20
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
Induction: 50%; Challenge: 25%
No. with + reactions:
2
Total no. in group:
20
Remarks on result:
other: positive control in independent reliability check
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
Induction: 70%, Challenge: 60%
No. with + reactions:
1
Total no. in group:
10
Clinical observations:
1/10 animals showed slight, patchy erythema on the left flank only
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
Induction: 70%, Challenge: 60%
No. with + reactions:
2
Total no. in group:
20
Clinical observations:
2/20 animals showed slight, patchy erythema on the left flank only
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
Induction: 50%; Challenge: 25%
No. with + reactions:
5
Total no. in group:
20
Remarks on result:
other: positive control in independent reliability check
Key result
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
test chemical
Dose level:
Induction: 70%, Challenge: 60%
No. with + reactions:
0
Total no. in group:
20
Key result
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
negative control
Dose level:
Induction: 70%, Challenge: 60%
No. with + reactions:
0
Total no. in group:
10
Key result
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
positive control
Dose level:
Induction: 50%; Challenge: 25%
No. with + reactions:
1
Total no. in group:
20
Remarks on result:
other: positive control in independent reliability check

Any other information on results incl. tables

Skin rections, induction phases

The 3rd induction with a 70% solution caused slight skin irritation in 2/20 treatment animals.

Skin reactions, challenge phase

At the first reading, 1/10 control animals had slight, patchy erythema on the challenge site on the left flank. 1/10 in the control group had slight, patchy erythema on the right flank at the second reading, while 2/20 treatment animals had slight, patchy erythema on the left flank at the second reading. All skin irritation effects had cleared within 72 hours after exposure ended.

Table 1: Skin reactions 24, 48 and 72 hours after challenge

 

24 hours

48 hours

72 hours

group

(# of animals)

flank

control

(10)

l/r

treatment

(20)

l/r

control

(10)

l/r

treatment

(20)

l/r

control

(10)

l/r

treatment

(20)

l/r

none

10/9

20/20

9/10

18/20

10/10

20/20

slight

0/1

0/0

1/0

2/0

0/0

0/0

weak

0/0

0/0

0/0

0/0

0/0

0/0

moderate

0/0

0/0

0/0

0/0

0/0

0/0

strong

0/0

0/0

0/0

0/0

0/0

0/0

l: left flank, induction site and challenge site

r: right flank, challenge site

Mortality and body weight

There was no mortality during the study period and the animals in the treatment group showed a similar gain in body weight compared with the control group.

Applicant's summary and conclusion

Interpretation of results:
other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No 1272/2008

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