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Toxicological information

Skin sensitisation

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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:
key study
Study period:
No data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
This study was conducted according to OECD guideline 406 and under GLP conditions. Due to the read-across purpose it was given a Klimisch 2 rating, in accordance with the ECHA Practical guide #6 on the reporting of read-across in IUCLID. The justification for read across is provided in the attached background material of this endpoint study record.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): Cyclobutanate
- Molecular formula (if other than submission substance): C14H20O2
- Molecular weight (if other than submission substance): 220.31
- Smiles notation (if other than submission substance): C12C(CC(C\3C1C\C=C3)C2)OC(=O)CCC
- InChl (if other than submission substance): 1/C14H20O2/c1-2-4-14(15)16-13-8-9-7-12(13)11-6-3-5-10(9)11/h3,5,9-13H,2,4,6-8H2,1H3
- Structural formula attached as image file (if other than submission substance): See file Cyclobutanate_Structure.jpg in section attached background information
- Stability under test conditions: Stable

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: David Hall Limited, Burton-on-Trent, Staffordshire, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 300-450
- Housing: Singly or in pairs, standard laboratory conditions
- Diet (e.g. ad libitum): Ad libitum (certified guinea pig diet)
- Water (e.g. ad libitum): Ad libitum (tap water)
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
arachis oil
Concentration / amount:
Intradermal induction: 5%
Epicutaneous induction: 100%
Epicutaneous challenge: 100% and 75%
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
arachis oil
Concentration / amount:
Intradermal induction: 5%
Epicutaneous induction: 100%
Epicutaneous challenge: 100% and 75%
No. of animals per dose:
Test group: 20 males
Control group: 10 males
Details on study design:
RANGE FINDING TESTS:
Intradermal: two guinea pigs injected with 1% and 5% test substance in arachis oil BP. Highest concentration at which only mild to moderate skin irritation was observed and which was well tolerated systemically is selected for the main study: 5%.
Epicutaneous induction: two guinea pigs treated with 100%, 75%, 50% and 25% test material in arachis oil BP (48 hours). Highest concentration at which only mild to moderate skin irritation was observed is selected for the main study: 100%.
Epicutaneous challenge: two guinea pigs treated with 100%, 75%, 50% and 25% test material in arachis oil BP (24 hours). Highest non-irritating concentration and one lower were selected for the main study: 100% and 75%.

MAIN STUDY
A. INDUCTION EXPOSURE
According to guideline:
- No. of exposures: 2 (intradermal and epicutaneous)
- Exposure period: 48 hours (epicutaneous)
- Test group: induction with Cyclobutanate
- Control group: test material omitted (intradermal and epicutaneous)
- Site: Shoulder
- Concentrations:
Intradermal: 5% in arachis oil BP (one of three injections)
Epicutaneous: 100%

B. CHALLENGE EXPOSURE
According to guideline:
- No. of exposures: 1
- Day of challenge: 21
- Exposure period: 24 hours
- Site: Flank
- Concentrations: 100% on right flank, 75% on left flank
- Evaluation (hr after challenge): 24 and 48 hours
Challenge controls:
Not induced (only vehicle), challenged as test group
Positive control substance(s):
yes
Remarks:
historical (2-Mercaptobenzothiazole and alpha-Hexylcinnamaldehyde)

Study design: in vivo (LLNA)

Concentration:
Not relevant
No. of animals per dose:
Not relevant
Details on study design:
Not relevant
Statistics:
Not relevant

Results and discussion

Positive control results:
Historically:
- 2-Mercaptobenzothiazole: sensitisation rate 100% in all 3 studies
- alpha-Hexylcinnamaldehyde: sensitisation rate of 20%, 40% and 50%

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100%
No. with + reactions:
8
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 100%. No with. + reactions: 8.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
100%
No. with + reactions:
1
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 100%. No with. + reactions: 1.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100%
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: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
75% in arachis oil BP
No. with + reactions:
6
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 75% in arachis oil BP. No with. + reactions: 6.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
75% in arachis oil BP
No. with + reactions:
2
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 75% in arachis oil BP. No with. + reactions: 2.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
75% in arachis oil BP
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: 75% in arachis oil BP. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
75% in arachis oil BP
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 75% in arachis oil BP. No with. + reactions: 0.0. Total no. in groups: 10.0.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: Not relevant
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Not relevant

Any other information on results incl. tables

Effects noted after induction:

- Discrete or patchy moderate and confluent erythema was noted at the intradermal induction sites of test and control group animals

- Discrete or patchy erythema noted at topical induction sites of test group animals. Bleeding from intradermal injection sites was noted in 9 test group animals after 1 hour. Control animals: discrete or patchy erythema at topical induction site

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Under the conditions of this study, a positive skin reaction was seen in 8 out of 20 guinea pigs 24 hours after challenge. These reactions were not considered sensitising, as they were not apparent after 48 hours (sensitisation rate: 0%). Based on these results, Cyclobutanate does not need to be classified as sensitising according to the criteria outlined in Annex I of 1272/2008/EC and Annex VI of 67/548/EEC.
Executive summary:

This Guinea Pig Maximisation Test (GPMT) was performed according to OECD guideline 406. The sensitising potential of Cyclobutanate was determined. Intradermal induction was performed with 5% Cyclobutanate in arachis oil BP, epicutaneous induction with 100% test material and epicutaneous challenge with 100 and 75% concentrations.

After induction injection discrete/patchy moderate and confluent erythema was noted at the intradermal induction sites of test and control group animals. Discrete or patchy erythema was also noted after topical induction of test group animals on the induction sites. Bleeding from intradermal injection sites was noted in 9 test group animals after 1 hour. The control animals showed discrete or patchy erythema at topical induction site.

At challenge, 8 and 0 out of 20 test group animals (100% Cyclobutanate) showed a positive skin reaction at the 24 and 48 hour reading. For the control group, this was 1 and 0 out of 10. In the 75% Cyclobutanate group, 6 and 0 out of 20 animals responded positive. In the control group 2 and 0 positive skin reactions were observed.

Under the conditions of this study, a positive skin reaction was seen in 8 out of 20 guinea pigs 24 hours after challenge. These reactions were not considered sensitising, as they were not apparent after 48 hours (sensitisation rate: 0%). Based on these results, Cyclobutanate does not need to be classified as sensitising according to the criteria outlined in Annex I of 1272/2008/EC and Annex VI of 67/548/EEC.