(2E)-2-ethyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)but-2-en-1-ol

Endpoint summary

Description of key information

In a Magnusson & Kligman maximisation study performed according to OECD guideline 406 and in compliance with GLP, groups of 20 female guinea pigs were induced intradermally at10% w/v and then topically with undiluted material. When challenged at 75 % v/v, no positive response was observed in induced animals.

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:

From October 22 to December 6, 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study conducted in compliance with OECD guideline 406 with minor deviations: lack of data about test substance.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

no data on purity and certificate of analysis of test substance

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The study is a guinea maximisation test conducted in 1987.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Interfauna (UK) Limited, Huntingdon, UK
- Age at study initiation: 7-10 weeks
- Weight at study initiation: 308-395 g
- Housing: Housed in groups of up to four in solid-floor polypropylene cages
- Diet (e.g. ad libitum): Guinea Pig FD1 Diet (Special Diets Services Limited, Witham, UK), ad libitum
- Water (e.g. ad libitum): Mains tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23 °C
- Humidity (%): 40-65%
- Air changes (per hour): 15/hour
- Photoperiod (hours dark / hours light): 12 hours dark / 12 hours light

Route:

intradermal and epicutaneous

Vehicle:

other: arachis oil (induction) and absolute ethanol (challenge)

Concentration / amount:

Range finding test:
- Intradermal induction exposure: 1, 5, 10 or 25% w/v in arachis oil
- Topical induction or challenge exposure: 50, 75 or 100% w/v in absolute ethanol

Main test:
- Intradermal induction exposure: 10% w/v in arachis oil
- Topical induction exposure: Undiluted
- Topical challenge exposure: 75% v/v in absolute ethanol

Route:

epicutaneous, occlusive

Vehicle:

other: arachis oil (induction) and absolute ethanol (challenge)

Concentration / amount:

Range finding test:
- Intradermal induction exposure: 1, 5, 10 or 25% w/v in arachis oil
- Topical induction or challenge exposure: 50, 75 or 100% w/v in absolute ethanol

Main test:
- Intradermal induction exposure: 10% w/v in arachis oil
- Topical induction exposure: Undiluted
- Topical challenge exposure: 75% v/v in absolute ethanol

No. of animals per dose:

- Range finding test: 1 or 2 animals/dose
- Main test: 10 and 20 animals for control and test, respectively

Details on study design:

RANGE FINDING TESTS:
- Intradermal induction exposure: Guinea pigs (1/dose) received injections (0.1 mL) of test material at concentrations of 1, 5, 10 or 25% w/v in arachis oil and observed for systemic toxicity and dermal irritation reactions at 24, 48 and 72 hours and 7 days
- Topical induction or challenge exposure: One or two guinea pigs [intradermally injected with Freund's Complete Adjuvant (FCA) 7 days earlier] applied with up to two dose levels of test material (50, 75 or 100% v/v) in absolute ethanol and observed for dermal irritation reactions at 1, 24 and 48 hours


MAIN STUDY
A. INDUCTION EXPOSURE: INTRADERMAL
- No. of exposures: One
- Test groups: Intradermally injected with 0.1 mL of FCA, 10% w/v test material in arachis oil and 10% w/v test material emulsion in 1:1 preparation of FCA plus arachis oil on Day 0
- Control group: Intradermally injected with FCA, arachis oil or FCA plus arachis oil (1:1) on Day 0
- Site: Shoulder region (40 mm x 60 mm) on each side of mid-line
- Duration: Days 0-6

B. INDUCTION EXPOSURE: TOPICAL
- No. of exposures: One
- Exposure period: 48 hours
- Test groups: Filter paper patch loaded with undiluted test material (0.2-0.3 mL) topically applied on Day 7 via occlusive patch
- Control group: Only filter paper patch topically applied on Day 7 via occlusive patch
- Site: Shoulder region on each side of mid-line
- Frequency of applications: Single application
- Duration: Days 7-21

C. CHALLENGE EXPOSURE: TOPICAL
- No. of exposures: One
- Day of challenge: Day 21
- Exposure period: 24 hours
- Test groups: Filter paper patch loaded with 0.1-0.2 mL of 75% v/v test material in absolute ethanol topically applied on Day 21 via occlusive patch
- Control group: Filter paper patch loaded with vehicle only topically applied on Day 21 via occlusive patch
- Site: 0 (vehicle) or 75% v/v test material in absolute ethanol was applied to left or right shorn flank (50-70 mm X 50 mm), respectively
- Evaluation (hour after removal of challenge patch): 24 or 48 hours

Challenge controls:

A patch loaded with the vehicle only applied to the left flank via occlusive patch

Positive control substance(s):

yes

Remarks:

Historical data: Formaldehyde (40% aqueous solution)

Positive control results:

Historical data (From March 4 to 28, 1987): Incidence of sensitisation for 40% formaldehyde was 95% (19/20) and classified as an extreme sensitiser to guinea pig skin.

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

40% v/v formaldehyde

No. with + reactions:

20

Total no. in group:

20

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

75% v/v in ethanol

No. with + reactions:

0

Total no. in group:

20

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

75% v/v in absolute ethanol

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

None

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 75% v/v in absolute ethanol. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: None.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

75% v/v in absolute ethanol

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

None

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 75% v/v in absolute ethanol. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: None.

Table 1: Intradermal sighting test - summary of results

 

Animal identification	Time of observation	Concentration of test material in arachis oil (% w/v)	Evidence of necrosis	Evidence of systemic toxicity
A	24 hours	1	None	None
	48 hours		None	None
	72 hours		None	None
	7 days		None	None
B	24 hours	5	None	None
	48 hours		None	None
	72 hours		None	None
	7 days		None	None
C	24 hours	10	None	None
	48 hours		None	None
	72 hours		None	None
	7 days		None	None
D	24 hours	25	Necrosis	None
	48 hours		Necrosis	None
	72 hours		Eschar	None
	7 days		Eschar	None

Conclusion: The concentration of the test material selected for the intradermal induction stage of the main study was 10% w/v in arachis oil BP

 

Table 2: Topical sighting test: Evaluation of reactions

 

Animal identification	Concentration of test material in absolute alcohol (% v/v)	Evaluation of application sites (hours after removal of patches)
		1	24	48
E	100	2	0	0
	50	2	0	0
F	100	2	0	0
	50	1	0	0
G	100	2	1	0
	75	1	0	0
H	100	2	1	0
	75	2	0	0

Conclusion: The undiluted test material and 75% (v/v) in absolute ethanol were selected for the main study topical induction and challenger, respectively.

 

Table 3: Main test: Topical induction - evaluation of reactions in test animals

No. of animals	Skin reaction (immediately after removal of dressings)
Test material: HR 87/600001
5	0
12	1
3	2
Control: Blank patch only
10	0

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

The test item is not classified according to Directive 67/548/EEC and CLP Regulation (EC) n° 1272/2008.

Executive summary:

In a Magnusson & Kligman maximisation study (GPMT) performed according to OECD guideline 406 and in compliance with GLP, groups of 20 female albino Dunkin-Hartley guinea pigs were intradermally induced with three injections of 0.1 mL of FCA, 10% w/v of test item in arachis oil and 10% w/v of test item emulsion in FCA on Day 0 on shoulder region on each side of mid-line. Control group of 10 animals was induced with FCA, arachis oil and 50% w/v arachis oil in FCA intradermal injections. After one week the same area was topically induced with 0.2-0.3 mL of undiluted test material via occluded filter paper patch for 48 hours for the treated group. Control group was patched with nothing applied to the filter paper. After 2 weeks of rest period, a challenge patch of 0 or 75% v/v test material in absolute ethanol was applied to left or right shorn flank of all animals, respectively. The test concentrations for the main study were determined from a sighting study using one or two animals.

 

Intradermal and topical induction indicated evidence of dermal irritation. No skin reactions were noted at the challenge sites of the test or control group animals at the 24 or 48-hour observations. The test item produced a 0% (0/20) sensitisation rate and was considered to be a nonsensitiser to guinea pig skin. Historical data on positive control (40% formaldehyde) exhibited evidence of sensitisation.

 

Therefore, the test item is not classified according to Directive 67/548/EEC and CLP Regulation (EC) n° 1272/2008.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In a Magnusson & Kligman maximisation study performed according to OECD guideline 406 and in compliance with GLP, groups of 20 female guinea pigs were induced intradermally at 10% w/v and then topically with undiluted material. When challenged at 75 % v/v, no positive response was observed in induced animals.

In a Magnusson & Kligman maximisation study performed similarly to OECD Guideline 406, 6 females and 4 males were induced intradermally at 2% v/v and then topically with undiluted material. When challenged at 25 % v/v, 2/9 animals had a positive response.

Migrated from Short description of key information:
The test substance was found negative in two Magnusson & Kligman maximisation studies.

Justification for selection of skin sensitisation endpoint:
GLP study conducted in compliance with OECD guideline 406 with only minor deviations

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

As the substance was found negative in two Magnusson & Kligman maximisation studies, it is not classified according to Directive 67/548/EEC and CLP Regulation (EC) n° 1272/2008.