cyclohexadecanone

Endpoint summary

Description of key information

Skin sensitisation (OECD 406): not sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 Feb - 16 Mar 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The concentration of the test substance used for epicutanous induction was not testet at levels >25% in order to cause potential mild skin irritation.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

(1992)

Deviations:

yes

Remarks:

The concentration of the test substance used for epicutanous induction was not testet at levels >25% in order to cause potential mild skin irritation.

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

Commission Directive 96/54/EC

Deviations:

yes

Remarks:

The concentration of the test substance used for epicutanous induction was not testet at levels >25% in order to cause potential mild skin irritation.

GLP compliance:

yes (incl. QA statement)

Remarks:

MINISTERIUM FÜR RAUMORDNUNG UND UMWELT DES LANDES SACHSEN-ANHALT, Germany

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The test was done before LLNA as first-choice method for in-vivo testing was set into force.

Species:

guinea pig

Strain:

Dunkin-Hartley

Remarks:

Crl:(HA)BR

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Microbiological status of animals: SPF
- Age at study initiation: approx. 31 days
- Weight at study initiation: 271.2 ± 18.3 g
- Housing: in groups up to 5 in Makrolon Type 4 cages, granulated soft wood bedding
- Diet: ALTROMIN 1322, standard diet for guinea pigs (ALTROMIN, Lage/Lippe, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 24
- Humidity (%): 30 - 60
- Photoperiod (hrs dark / hrs light): 12 / 12

Route:

intradermal

Vehicle:

arachis oil

Concentration / amount:

5%

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Route:

epicutaneous, occlusive

Vehicle:

other: ethanol/diethylphthalate 1:1

Concentration / amount:

25%

Adequacy of induction:

other: non irritant substance at 25%, but pretreated with 10% SDS

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: ethanol/diethylphthalate 1:1

Concentration / amount:

25%

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10 (controls), 20 (in test gorups)

Details on study design:

RANGE FINDING TEST:
The aim of the range finding test was to find out the highest concentrations which cause mild-to-moderate skin irritation after intracutaneous and epicutaneous administration and the highest non-irritant concentration after epicutaneous administration. All animals used for the range finding study were pretreated intradermally with a mixture of FCA and water 1:1 (v/v) in the flank region 24 h before testing. For the intracutaneous tollerance test 4 concentrations of the test substance (1, 2, 3 and 5%(w/v)) in arachis oil were injected intradermally into the clipped/shaved skin of two animals. The highest concentration (5%) induced erythema (grade 1) and edema 24, 48 and 72 h after administration in one animal and was selected for the intradermal induction phase of the main study. For the epicutaneous tolerance test two animals were treated with 4 concentrations of the test substance (1, 5, 10 and 25%) in ethanol/diethylphthalate 1:1 (v/v). Applications were made to the clipped/shaved flanks under occlusive dressings for 24 hours. The test item did not cause any irritating effects, therefore the 25% (w/v) concentration was chosen for epicutaneous induction and challenge application of the main study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous, respectively)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: a 1:1 mixture (v/v) FCA/water
Injection 2: 5% (w/v) test substance in arachis oil
Injection 3: 5% (w/v) test substance in a 1:1 mixture (v/v) FCA/water
Epicutaneous: 25% (w/v) test substance in a 1:1 mixture (v/v) ethanol/diethylphthalate
- Control group:
Intradermal (3 pair of injections):
Injection 1: a 1:1 mixture (v/v) FCA/water
Injection 2: arachis oil
Injection 3: 50% mixture (w/v) arachis oil in a 1:1 mixture (v/v) FCA/water
Epicutaneous: 1:1 mixture (v/v) ethanol/diethylphthalate
- Site: shoulder region (intradermal + epicutaneous)
- Frequency of applications: every 7 days
- Duration: Days 0-8
- Concentrations: intradermal 5%, epicutaneous 25%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Days of challenge: 21
- Exposure period: 24 h
- Test groups: test substance and vehicle (1:1 mixture (v/v) ethanol/diethylphthalate)
- Control group: vehicle
- Site: right flank (25% test substance) and left flank (vehicle)
- Concentrations: 0%, 25%
- Evaluation: 24 and 48 h after challenge patch removal

OTHER:
Because the test substance (25%) was non-irritating after epicutaneous administration during the pilot study, a pretreatment of the skin with 10% sodium lauryl sulphate in vaseline was carried out before induction by epicutaneous administration.

Challenge controls:

The control group is actually a challenge control.

Positive control substance(s):

yes

Remarks:

Benzocain, Induction: intradermal 2% in water, epicutaneous 25% in liquid paraffin, challenge: 10% in liquid paraffin

Positive control results:

The positive control is a historical background data group from a study performed during November/December 2000 under same experimental conditions. The epicutaneous administration of the 10 % suspension of Benzocaine in liquid paraffin caused a slight to moderate erythema (grade 1-2) in all animals of the dose group on day 23. In 9 of 10 animals these irritating signs were also observed on day 24. The skin-fold thickness was statistically significantly increased in the treated animals on all days of measurement after challenge. Thus, reliability criteria for the Guinea Pig Maximisation Test is met.

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

Induction: 0% Challenge: 0%

No. with + reactions:

0

Total no. in group:

10

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

Induction: 0% Challenge: 25%

No. with + reactions:

0

Total no. in group:

10

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Induction: 5% Challenge: 0%

No. with + reactions:

0

Total no. in group:

20

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Induction: 5% Challenge: 25%

No. with + reactions:

0

Total no. in group:

20

Reading:

2nd reading

Hours after challenge:

72

Group:

negative control

Dose level:

Induction: 0% Challenge: 0%

No. with + reactions:

0

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

72

Group:

negative control

Dose level:

Induction: 0% Challenge: 25%

No. with + reactions:

0

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

Induction: 5% Challenge: 0%

No. with + reactions:

0

Total no. in group:

20

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

Induction: 5% Challenge: 25%

No. with + reactions:

0

Total no. in group:

20

Group:

positive control

Remarks on result:

not measured/tested

The administration of the 25% (w/v) solution of the test item in vehicle to the right flank did not cause any irritation signs in the animals of the dose group just as in the animals of the control group. The administration of vehicle to the left flank did also not cause any irritation signs in all animals. The measurement of the skin-fold thickness showed no substance dependent difference between control and treated animals. The mean value of the skin-fold thickness of the animals of the dose group was on both sides approximately 0.1 mm lower compare to the animals of the control group each time observed. This difference is in the range of the sensitivity of measurement procedure and could be evaluated as accidental. No animal died or showed clinical signs during the course of investigation and the mean value for body weight and the body weight gain were not affected by the treatment.

Interpretation of results:

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

Conclusions:

Under the conditions of the guinea pig maximisation test the test substance revealed no sensitising properties.

Executive summary:

The skin sensitising potential of the test substance was investigated in a guinea pig maximisation test (GPMT test) according to OECD Guideline 406 and in compliance with GLP (2001). Based on the results of a preliminary study, a 5% (w/v) solution of the test item in arachis oil was used for intradermal induction (stage 1) at day 0 and a 25% (w/v) solution of the test item in ethanol/diethylphthalate 1:1 was used for epicutaneous induction (stage 2) on day 7. A 25% (w/v) solution of the test substance in ethanol/diethylphthalate 1:1 and the undiluted test substance were selected for the challenge on day 21. In the main study, 10 animals were used to investigate the skin sensitising potential of the test substance. In addition, 5 animals treated with arachis oil BP only served as vehicle reference. Magnusson/Kligman scale was used to evaluate the skin reactions. In the first induction stage (intradermal) on day 0, animals treated with 5% solution of the test substance showed slight erythema (grade 1-2) and oedema. Because the test item was non-irritating in the preliminary study after epicutaneous administration at a dose of 25%, a pretreatment of the skin with 10% sodium lauryl sulphate in vaseline was carried out 24 h before epicutaneous induction on day 6. In the second induction stage (epicutaneous) on day 7, a filter paper patch saturated with the 25% dilution of the test substance was applied to the clipped/shaved flanks under occlusive dressings for 48 h. The pretreatment caused a slight to moderate erythema (grade 1-2) in all animals. The epicutaneous administration of the test substance did not increase this moderate irritation. Slight erythema (grade 1) was observed in 17 of 20 animals of the dose group and in 7 of 10 control animals of the control group on day 9. This effect was reversible within the next 24 h. On day 21, the animals were challenged with the 25% (w/v) solution of the test substance in ethanol/diethylphthalate 1:1 and the vehicle only by occluded patches for 24 h to the left and right flank, respectively. No skin reactions at the challenge sites of the test or control group animals were observed 24 and 48 h after challenge patch removal. No animal died or showed clinical signs during the course of investigation and the mean values of the body weights and the body weight gain were not affected by the treatment. Based on the results of this GPMT, the test substance was not regarded as a skin sensitizer under the conditions of the test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The skin sensitising potential of the test substance was investigated in a guinea pig maximisation test (GPMT test) according to OECD Guideline 406 and in compliance with GLP (2001). Based on the results of a preliminary study, a 5% (w/v) solution of the test item in arachis oil was used for intradermal induction (stage 1) at day 0 and a 25% (w/v) solution of the test item in ethanol/diethylphthalate 1:1 was used for epicutaneous induction (stage 2) on day 7. A 25% (w/v) solution of the test substance in ethanol/diethylphthalate 1:1 and the undiluted test substance were selected for the challenge on day 21. In the main study, 10 animals were used to investigate the skin sensitising potential of the test substance. In addition, 5 animals treated with arachis oil BP only served as vehicle reference. Magnusson/Kligman scale was used to evaluate the skin reactions. In the first induction stage (intradermal) on day 0, animals treated with 5% solution of the test substance showed slight erythema (grade 1-2) and oedema. Because the test item was non-irritating in the preliminary study after epicutaneous administration at a dose of 25%, a pretreatment of the skin with 10% sodium lauryl sulphate in vaseline was carried out 24 h before epicutaneous induction on day 6. In the second induction stage (epicutaneous) on day 7, a filter paper patch saturated with the 25% dilution of the test substance was applied to the clipped/shaved flanks under occlusive dressings for 48 h. The pretreatment caused a slight to moderate erythema (grade 1-2) in all animals. The epicutaneous administration of the test substance did not increase this moderate irritation. Slight erythema (grade 1) was observed in 17 of 20 animals of the dose group and in 7 of 10 control animals of the control group on day 9. This effect was reversible within the next 24 h. On day 21, the animals were challenged with the 25% (w/v) solution of the test substance in ethanol/diethylphthalate 1:1 and the vehicle only by occluded patches for 24 h to the left and right flank, respectively. No skin reactions at the challenge sites of the test or control group animals were observed 24 and 48 h after challenge patch removal. No animal died or showed clinical signs during the course of investigation and the mean values of the body weights and the body weight gain were not affected by the treatment. Based on the results of this GPMT, the test substance was not regarded as a skin sensitizer under the conditions of the test.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on skin sensitisation of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.