A mixture of cis- and trans-cyclohexadec-8-en-1-one

Endpoint summary

Description of key information

In a key Guinea Pig Maximisation Test similar to OECD guideline 406, the test item was not sensitising under the conditions of the test.

 

In a disregarded Guinea Pig Maximisation Test according to OECD guideline 406, the test item did not induce delayed contact hypersensitivity in guinea pigs and was thus considered non-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:

1986-06-19 to 1986-09-03

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

According to draft OECD 406 and GLP

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

According to draft OECD 406 and GLP, but topical induction used 25% non irritating concentration without SLS pretreatment and challenge concentration of 5% could have been chosen higher.

Principles of method if other than guideline:

- Principle of test: Guinea pig maximisation test according to draft OECD 406
- Short description of test conditions: Test conditions were chosen according to OECD 406, but topical induction used 25% non irritating concentration without SLS pretreatment and challenge concentration of 5% could have been chosen higher.

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The test was carried out before entry into force of Regulation (EC) No 1907/2006, and meet the requirements set out in Article 13(3), first subparagraph and Article 13(4). Thus, this Guinea Pig Maximisation Test shall be considered appropriate to address this standard information requirement for skin sensitisation.

Species:

guinea pig

Strain:

other: SPF-bred, albino guinea pigs (Bor:DHPW)

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Females nulliparous and non-pregnant: Yes
- Microbiological status of animals: SPF
- Age at study initiation: Young
- Weight at study initiation: 281-329 g (males), 280-330 g (females)
- Housing: Individually under conventional conditions in suspended, stainless steel cages, fitted with wire mesh floor and front
- Diet: Ad libitum (pelleted, natural ingredient diet)
- Water: Ad libitum (unfluoridated tap water)
- Acclimation period: 5 days
- Indication of any skin lesions: No visible skin abnormalities

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 + 2
- Humidity (%): 40-70
- Air changes (per hr): At least 10
- Photoperiod (hrs dark / hrs light): 12/12
- IN-LIFE DATES: From day 0 to day 23

Route:

intradermal and epicutaneous

Vehicle:

polyethylene glycol

Concentration / amount:

Intradermal
- two injections (0.1 mL) with Freund's Complete Adjuvant (FCA)
- two injections (0.1 mL) with a 25% dilution (v/v) of the test item in PG
- two injections (0.1 mL) with a 25% dilution (v/v) of the test item in FCA and PG (1:1)
Epicutaneous
25% (w/w) mixture of the test substance with vaseline

Day(s)/duration:

7 days (from intradermal injection to topical application) + 48 hours (topical application) + 12 days from removal of topical application until challenge

Adequacy of induction:

other: Intradermal injections induced moderate to severe erythema and abscesses in all test animals. The topical applications did not induce any reactions.

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: Vaseline

Concentration / amount:

5%

Day(s)/duration:

1 day

Adequacy of challenge:

other: The challenge treatment with the 5% dilution of the test substance in vaseline did not induce skin reactions in any of the test animals or the controls, either after 24 h or after 48 h.

No. of animals per dose:

10 animals per sex were treated with a single dose of the test item or with a control treatment

Details on study design:

RANGE FINDING TESTS: The irritation response upon intradermal injection of various concentrations was examined in 3 guinea pigs. A sufficiently lange area of the scapular region was clipped free of hair with electric clippers. Subsequently 0.1 mL portions of 5, 10 and 25% (v/v) dilutions of the test substance in propylene glycol (PG), were applied to each animal by intradermal injection. Skin readings were made after 24 h. A dilution causing slight to moderate irritation is usually taken for intradermal injection of the test substance in the induction phase of the main test. The irritation response upon topical treatment was tested in 6 other guinea pigs. Both flanks of each animal were clipped free of hair with electric clippers. Subsequently several 2 x 2 cm patches of filter paper (Whatman No. 3 MM) were loaded with different concentrations of the test substance in vaseline, viz. 5, 10 or 25% (w/w). The patches were placed an the clipped skin and covered with a piece of PVC foil and hypo-allergenic paper bandage (Leukopor) which was then secured by elastic adhesive bandage (Tensoplast), 7.5 cm in width, wound around the torso of the animal. One concentration was tested in two animals. The dressing was left in place for 24 h. Then the animals were examined for signs of irritation. A concentration causing slight to moderate irritation is usually chosen for topical induction and a non-irritant concentration for topical challenge.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Two (intradermal injections and one week later, a topical application over the injection sites)
- Exposure period: 9 days (7 days after intradermal injection, a topical induction was left in place for 48 h)
- Test groups: One test group was treated with three pairs of simultaneous intradermal injections:
two injections (0.1 mL) with Freund's Complete Adjuvant (FCA)
two injections (0.1 mL) with a 25% dilution (v/v) of the test substance in PG
two injections (0.1 mL) with a 25% dilution (v/v) of the test substance in FCA and PG (1:1)
- Control group: One control group was treated with three pairs of simultaneous intradermal injections:
two injections (0.1 mL) with FCA
two injections (0.1 mL) with PG
two injections (0.1 mL) with FCA and PG (1:1)

One week after the intradermal injections, the induction by topical application was made in the same region. A patch of filter paper was loaded with a 25% (w/w) mixture of the test substance with vaseline. The patch was placed over the sites of the intradermal injections and was secured. The dressing was left in place for 48 hours. The control animals were similarly treated with patches loaded with vaseline only. Skin readings were made directly after removal of the patches.
- Site: Scapular region
- Duration: 21 days (7 days from intradermal injection until topical application, 48 hours topical application and 12 days between removal of topical application until challenge)
- Concentrations: 25% (w/w) (intradermal and topical)

B. CHALLENGE EXPOSURE
- No. of exposures: One topical challenge
- Day of challenge: On day 21
- Exposure period: 24 hours
- Test groups: The test group was treated with 5% (w/w) mixture of the test substance with vaseline
- Control group: The control group was treated with 5% (w/w) mixture of the test substance with vaseline
- Site: Right flank of each animal
- Concentrations: 5% (w/w) mixture of the test substance with vaseline
- Evaluation (hr after challenge): 24 and 48

Challenge controls:

Vaseline

Positive control substance(s):

no

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

Not tested

Remarks on result:

not measured/tested

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

Not tested

Remarks on result:

not measured/tested

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

vehicle control during induction, 5% substance during challenge

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

All animals remained in good health during the experimental period.

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

vehicle control during induction, 5% substance during challenge

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

All animals remained-in good health during the experimental period.

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25% during induction, 5% substance during challenge

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

All animals remained-in good health during the experimental period.

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25% during induction, 5% substance during challenge

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

All animals remained-in good health during the experimental period.

Remarks on result:

no indication of skin sensitisation

Interpretation of results:

GHS criteria not met

Conclusions:

In a Guinea Pig Maximisation Test similar to OECD guideline 406, the test item was not sensitising under the conditions of the test.

Executive summary:

The test substance was examined for possible sensitizing properties by a maximization test in guinea pigs using 20 test animals and 20 controls. The test was conducted according to the draft OECD 406 guideline and GLP.

 

The test comprised:

1) induction treatment by intradermal injection of 25% test substance in propylene glycol, followed one week later by topical treatment with 25% in vaseline

2) challenge treatment, 14 days after the last induction, by topical application of 5% in vaseline

 

The challenge treatment with the 5% dilution did not induce signs of sensitization in any of the guinea pigs under the conditions of the test. Therefore, it was concluded that the test substance is a non-sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Key, Skin sensitisation in vivo, RL2

The test substance was examined for possible sensitizing properties by a maximization test in guinea pigs using 20 test animals and 20 controls. The test was conducted according to the draft OECD 406 guideline and GLP.

 

The test comprised:

1) induction treatment by intradermal injection of 25% test substance in propylene glycol, followed one week later by topical treatment with 25% in vaseline

2) challenge treatment, 14 days after the last induction, by topical application of 5% in vaseline

 

The challenge treatment with the 5% dilution did not induce signs of sensitisation in any of the guinea pigs under the conditions of the test. Therefore, it was concluded that the test substance is a non-sensitizer.

 

Disregarded, Skin sensitisation in vivo, RL3

The experimental design was performed according to the method of B. Magnusson and A. M. Kligman (OECD guideline 406) under GLP-like conditions. To test the sensitizing properties of the test compound, 20 test and 20 control animals were treated. Animals were first treated with three pairs of simultaneous intradermal injections bilateral of the spine:

Test group

two injections (0.05 mL) with Freund's Complete Adjuvant (FCA), diluted 1:1 in aqua dest.

two injections (0.05 mL) with a 1% dilution of the test item in 80% ethanol

two injections (0.05 mL) with a 1% dilution of the test item in FCA previously diluted 1:1 with Oleum arachidis

 Control group

two injections (0.05 mL) with FCA

two injections (0.05 mL) with 80% ethanol

two injections (0.05 mL) with 1% of 80% ethanol in FCA previously diluted 1:1 with Oleum arachidis

 

7 days after intradermal injections, the induction by topical application was made in the same region. 0.5 mL of 1% (w/w) test substance in 80% ethanol (treatment group) or 0.5 mL of 80% ethanol (control group) was applied directly to the treated areas. After the application, the treated areas were covered with a gauze pad and fixed to the animals trunk. The dressing was left in place for 48 hours. Afterwards, the test and control group was treated with 1% test substance in 80% ethanol on the left and right flank. Any reaction, especially erythema and edema was recorded 24 and 48 hours after the challenge. No irritation reactions were observed after intradermal and topical application. Thus, the substance concentration of 1% is not chosen high enough according to OECD guideline 406. No signs of sensitisation were oberserved 24 and 48 hours after challenge. According to the method used, the test compound is considered to cause no delayed contact hypersensitivity in guinea pigs at a test item concentration of 1%.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on available data on skin sensitisation, the test item is not classified and labelled according to Regulation (EC) No 1272/2008 (CLP), as amended for the eighteenth time in Regulation (EU) 2022/692.