Cyclopentanone

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The test substance purity was known. The screening protocol was well described even if GLP were not validated.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

only 5 animals were used in the treatment group

Principles of method if other than guideline:

Method: other: screening protocol similar to OECD guide-line 406 "skin sensitisation"

GLP compliance:

no

Remarks:

screening test

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

In vivo test was made in 1999 before the in vitro test strategies.

Test material

Test material information

Constituent 1

Reference substance name:

Cyclopentanone

EC Number:

204-435-9

EC Name:

Cyclopentanone

Cas Number:

120-92-3

Molecular formula:

C5H8O

IUPAC Name:

cyclopentanone

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

not specified

Details on test animals and environmental conditions:

- Source: Harlan Nossan S.r.l., Italy
No more data

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

polyethylene glycol

Induction 2

Concentration / amount:

Induction: 5% in PEG 200 (injection) and 100% (topical)
Challenge: 100 % (first challenge), 20 % in PEG 200 (second challenge)

Challenge

Challenge 1

Route:

epicutaneous, open

Vehicle:

polyethylene glycol

Challenge 2

Concentration / amount:

Induction: 5% in PEG 200 (injection) and 100% (topical)
Challenge: 100 % (first challenge), 20 % in PEG 200 (second challenge)

No. of animals per dose:

5

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- type of epicutaneous induction: data not available
- SLS application: yes (concentration unknown)
- Exposure period: day 1 (intradermal) and day 8 (epicutaneous)
- Test groups: In an attempt to induce sensitisation, test animals were intradermally injected with an emulsion of Freund's complete adjuvant and the test substance in both the selected vehicle and an emulsion of Freund's complete adjuvant. One week later this was boosted by topical application of the test substance over the injection sites which had been pre-treated with sodium lauryl sulphate to promote an irritant reaction.
- Control group: animals were treated in the same manner but the selected vehicle was used in place of the test substance.
- Site: data not available
- Frequency of applications: on days 1 and 8
- Duration: 8 days
- Concentrations: 5% in PEG 200 (injection) and 100% (topical)

- Rest period: 2 weeks (after the second stage of induction)

B. CHALLENGE EXPOSURE
- No. of exposures: 2
- Day(s) of challenge: 2 and 3 weeks after the second stage of induction
- Exposure period: data not available
- Test groups: both the vehicle and the test substance
- Control group: both the vehicle and the test substance
- Site: data not available
- Concentrations: 100 % (first challenge), 20 % in PEG 200 (second challenge)
- Evaluation: 24 and 48 h after challenge

Challenge controls:

no data

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Group:

test chemical

Remarks on result:

other: The test substance did not elicite a sensitisation response in the Guinea  pig, there was no evidence of reaction at challenge following a period of   induction exposure to cyclopentanone.

Results 2

Group:

positive control

Remarks on result:

not measured/tested

Results 3

Group:

negative control

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

Table 1: Results

1st CHALLENGE			2nd CHALLENGE
Control Group			Control Group
Animal	Reaction at challenge		Animal	Reaction at challenge
Number	24 Hours	48 Hours	Number	24 Hours	48 Hours
423	0	0	423	0	0
425	0	0	425	0	0
427	1	0c	427	0	0
Test Group			Test Group
Animal	Reaction at challenge		Animal	Reaction at challenge
Number	24 Hours	48 Hours	Number	24 Hours	48 Hours
429	0	0	429	0	0
431	1	1	431	0	0
433	0	0	433	0	0
435	1	0c	435	0	0
437	1	1	437	0	0
c = Yellow colouration of skin

The test substance did not elicite a sensitisation response in the Guinea  pig, there was no evidence of reaction at challenge following a period of  

induction exposure to cyclopentanone.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance did not elicite a sensitisation response in the Guinea  pig, there was no evidence of reaction at challenge following a period of  
induction exposure to cyclopentanone.

Executive summary:

In a dermal sensitization study (Nunziata A, 1999) with cyclopentanone (99.8% purity) in PEG 200, Dunkin-Hartley guinea pigs (5 in the test group, 3 in the control group) were tested using the method of maximization.
In an attempt to induce sensitisation, test animals were intradermally injected with an emulsion of Freund's complete adjuvant and the test substance in both the selected vehicle and an emulsion of  Freund's complete adjuvant. One week later this was boosted by topical application of the test substance over the injection sites which had been pre-treated with sodium lauryl sulphate to promote an irritant reaction. Control group animals were treated in the same manner but the selected vehicle was used in place of the test substance. Two weeks after the second induction stage, all animals were challenged by topical application of both the vehicle and the test substance. Irritation to the test substance was noted and challenge was repeated 1 week later using the test substance at a lower concentration.
The results indicate that the test substance does not elicit a sensitisation response in the guinea pig, there being no evidence of reaction at challenge following a period of induction exposure to the substance.