Fatty acids, C12-18 (even numbered)-methyl esters, sulfonated, sodium salts

Endpoint summary

Description of key information

In the key study, the test item produced reactions in 2/19 (11 %) of test animals following the challenge phase in a Magnusson & Kligman guinea pig maximisation test (OECD TG 406; EU Method B6).

In a supporting Magnusson & Kligman guinea pig maximisation test, the test item (36 % a.i. in aqueous solution) produced reactions in 6/19 (32 %) of test animals following the initial challenge. In the rechallenge positive reactions were noted in 4/19 (21 %) of the test animals. All four of these animals had responded to the initial challenge (OECD TG 406; EU Method B6).

On the basis of these two studies it is concluded that the test item is not classified as a skin sensitiser.

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:

29th December 1993 - 30th January 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

Commission Directive 92/69/EEC

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

An appropriate guinea pig maximisation test is available which would not justify conducting an additional LLNA due to animal welfare.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: David Hall Limited, Burton-on-Trent, Staffordshire, UK
- Females (if applicable) nulliparous and non-pregnant: not specified
- Microbiological status of animals, when known: not specified
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: 319-390 g
- Housing: The animals were housed in groups of up to three in solid-floor polypropylene cages furnished with woodflakes.
- Diet: ad libitum - Guinea Pig FD1 Diet, Special Diets Services Limited, Witham, Essex, UK
- Water: ad libitum - mains tap water
- Acclimation period: minimum 5 days
- Indication of any skin lesions: none

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-22
- Humidity (%):42-64
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12
- IN-LIFE DATES: From: To:

Route:

intradermal

Vehicle:

water

Concentration / amount:

0.1 %w/v

Day(s)/duration:

Day 0

Adequacy of induction:

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

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

10 %w/w

Day(s)/duration:

Day 7 - patches removed after 48 hours

Adequacy of induction:

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

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

2 and 5%w/w

Day(s)/duration:

Day 21 - patches removed after 24 hours

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

Main study: 20 guinea pigs used in test and 10 used as controls.

Details on study design:

RANGE FINDING TESTS:
Selection of concentration for intradermal induction: Four animals were intradermally injected with preparations of test material (0.1%, 0.5%, 1%, 5% w/v in distilled water). The highest concentration that did not cause local necrosis, ulceration or systemic toxicity was selected for the intradermal induction stage of the main study.
Selection of concentration for topical induction: Two guinea pigs (intradermally injected with Freund's Complete Adjuvant eight days earlier) were treated with four preparations of the test material (75%, 50%, 25% and 10% v/v in distilled water). The highest concentration producing only mild to moderate dermal irritation after a 48-hour occlusive exposure was selected for the topical induction stage of the main study.
Selection of concentration for topical challenge: Four preparations of the test material (10%, 5%, 2% and 1% v/v in distilled water) were applied occlusively to the clipped flanks of two guinea pigs for a period of 24 hours. These guinea pigs did not form part of the main study but had been treated identically to the control animals of the main study, up to Day 14. The highest non-irritant concentration of the test material and one lower concentration were selected for the topical challenge stage of the main study.


MAIN STUDY
A. INDUCTION EXPOSURE
Shortly before treatment on Day 0 the hair was removed from an area approximately 40 mm x 60 mm on the shoulder region of each animal with veterinary clippers. A row of three injections (0.1 mL each) was made on each side of the mid-line. The injections were:
i) Freund's Complete Adjuvant plus distilled water in the ratio 1:1
ii) a 0.1 % w/v formulation of the test material in distilled water
iii) a 0.1 % w/v formulation of the test material in a 1:1 preparation of Freund's Complete Adjuvant plus distilled water
Approximately 24 and 48 hours after intradermal injection the degree of erythema at the test material injection sites (site ii) was evaluated according to the Draize scale.
One week later (Day 7), the same area on the shoulder region used previously for intradermal injections was clipped again and treated with a topical application of the test material formulation (10 %w/w in distilled water). The test material formulation (0.2-0.3 mL) was applied on filter paper (WHATMAN No. 4; approximate size 40 mm x 20 mm) which was held in place with a strip of surgical adhesive tape covered with an overlapping length of aluminium foil. The patch and foil were further secured with a strip of elastic adhesive bandage. This occlusive dressing was kept in place for 48 hours. The degree of erythema and oedema was quantified one and 24 hours following removal of the patches using the Draize scale.
Induction of the control animals: Intradermal injections were administered using an identical procedure to that used for the test animals, except that the injections were:
i) Freund's Complete Adjuvant plus distilled water in the ratio 1:!
ii) distilled water
iii) 50 % w/v formulation of distilled water in a 1:1 preparation of Freund's Complete Adjuvant plus distilled water
The topical applications followed the same procedure as for the test animals except that the vehicle alone was applied to the filter paper. Skin reactions were quantified as for the test animals.

B. CHALLENGE EXPOSURE
Shortly before treatment on Day 21, an area of approximately 50 mm x 70 mm on both flanks of each animal was clipped free of hair with veterinary clippers. A quantity of 0.1-0.2 mL of the test material formulation (5 %w/w in distilled water) was applied to the shorn right flank of each animal on a square of filter paper (WHATMAN No. 4; approximate size 20 mm x 20 mm) whcih was held in place with a strip of surgical adhesive tape. To ensure that the maximum non-irritant concentration was used at challenge, the test material at a concentration of 2 % v/v in distilled water was similarly applied to a skin site on the left shorn flank. The patches were occluded with an overlapping length of aluminium foil and secured with a strip of elastic adhesive bandage. After 24 hours the dressing was carefully cut using blunt-tipped scissors, removed and discarded. The challenge sites were swabbed with cotton wool soaked in distilled water to remove residual material. Prior to the 24-hour observation the flanks were clipped using veterinary clippers to remove regrown hair. Approximately 24 and 48 hours after challenge dressing removal, the degree of erythema and oedema were quantified using the Draize scale.

Challenge controls:

See above for details of the challenge controls.

Positive control substance(s):

yes

Remarks:

Positive control data from the period January 1993 - November 1993 reported

Positive control results:

Refer to attachment for summary of positive control studies.

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

5 %w/w

No. with + reactions:

2

Total no. in group:

19

Clinical observations:

Very slight erythema (grade 1) at the challenge site of two animals

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

2 %w/w

No. with + reactions:

0

Total no. in group:

19

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

2 or 5 %w/w

No. with + reactions:

0

Total no. in group:

19

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

2 or 5 %w/w

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: vehicle control group

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

2 or 5 %w/w

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: vehicle control group

Reading:

other: postive controls covering study period

Group:

positive control

Remarks on result:

other: See attached document

Results of intradermal sighting test, topical sighting test for induction and topical sighting test for challenge application are attached. Based on the results of these studies, the following concentrations were selected for the main test: Intradermal Induction - 0.1 %w/v in distilled water; Topical Induction - 10 %w/w in distilled water; Topical Challenge - 5 % and 2 %w/w in distilled water.

Main study:

Skin reactions observed after intradermal induction: Very slight to well-defined erythema was noted at the intradermal induction sites of all test group animals at he 24 and 48 -hour observations. Very slight erythema was noted at the intradermal induction sites of five control group animals at the 24 -hour observation. No skin reactions were noted at the intradermal induction sites of control group animals at the 48 -hour observation. Results tables are attached.

Skin reactions observed after topical induction: One test group animal was found dead on day 10. The cause of death was not determined bu the adsence of this animal was considered not to affect the purpose or integrity of the study. Very slight to well-defined erythema with or without very slight oedema was noted at the induction sites of all test group animals at the one hour observation and in seventeen test group animals at the 24 -hour observation. Other skin reactions noted were small superficial scattered scabs and hardened, dark brown/black coloured scabs. Skin reactions prevented accurate evaluation of erythema at the induction sites of two test group animals at the 24 -hour observation. No skin reactions were noted at the treatment sites of control group animals at the one and 24 -hour observations. Results tables are attached.

Skin reactions observed after topical challenge:

5 %w/w in distilled water: Positive sensitisation responses, very slight erythema (grade 1) were noted at the challenge sites of two test group animals at the 24 -hour observation. no skin reactions were noted at the challenge sites of test group animals at the 48 -hour observation. No skin reactions were ntoed at teh challenge sites of control group animals at the 24 and 48 -hour observations.

2 %w/w in distilled water: No skin reactions were noted at the challenge sites of test and control group animals at the the 24 and 48 -hour observations.

Vehicle control: No skin reactions were noted at the vehicle control sites of test and control group animals at the 24 and 48 -hour observations.

Results tables for the challenge phase are attached.

Bodyweight: Bodyweight gains of guinea pigs in the test group, between Day 0 and Day 24, were comparable to those observed in the control group animals over the same period.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item produced reactions in2/19 (11 %) of test animals following the initial challenge. On this basis it is concluded that the test item is no classified as a sensitiser.

Executive summary:

The skin sensitisation potential of the test item in the guinea pig was investigated in a study performed according to OECD TG 406 and Method B6 of Commission Directive 92/69/EEC (Magnusson & Kligman Maximisation Test). Twenty test and ten control animals were used for the main study. Based on the results of sighting tests, the concentrations of test item for the induction and challenge phases were selected as follows: Intradermal Induction - 0.1 %w/v in distilled water; Topical Induction - 10 %w/w in distilled water; Topical Challenge - 5 % and 2 %w/w in distilled water. Following the initial challenge, the test item produced reactions in 2/19 (11 %) of the test animals. It can therefore be concluded that the test item is not classified as a sensitiser.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In the key study, the skin sensitisation potential of the test item in the guinea pig was investigated in a study performed according to OECD TG 406 and Method B6 of Commission Directive 92/69/EEC (Magnusson & Kligman Maximisation Test). Twenty test and ten control animals were used for the main study. Based on the results of sighting tests, the concentrations of test item for the induction and challenge phases were selected as follows: Intradermal Induction - 0.1 %w/v in distilled water; Topical Induction - 10 %w/w in distilled water; Topical Challenge - 5 % and 2 %w/w in distilled water. Following the challenge phase, the test item produced reactions in 2/19 (11 %) of the test animals. It can therefore be concluded that the test item is not classified as a sensitiser.

In a supporting study, the skin sensitisation potential of the test item (36 % a.i. aqueous solution) in the guinea pig was investigated in a study performed according to OECD TG 406 and Method B6 of Commission Directive 92/69/EEC (Magnusson & Kligman Maximisation Test). Twenty test and ten control animals were used for the main study. An additional ten control animals were used for the rechallenge. Based on the results of sighting tests, the concentrations of test item for the induction and challenge phases were selected as follows: Intradermal Induction - 0.1 %w/v in distilled water; Topical Induction - 10 %v/v in distilled water; Topical Challenge - 5 % and 2 %v/v in distilled water. A topical rechallenge was performed at concentrations of 5 % and 2 %v/v in distilled water. Following the initial challenge, the test item produced reactions in 6/19 (32 %) of the test animals. A rechallenge was performed in order to verify these results. Positive reactions were noted in 4/19 (21 %) of the test animals. All four of these animals had responded to the initial challenge, It can therefore be concluded that the test item is not classified as a sensitiser.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In the key study, the test item produced reactions in 2/19 (11 %) of test animals following the challenge phase in a Magnusson & Kligman guinea pig maximisation test (OECD TG 406; EU Method B6).

In a supporting Magnusson & Kligman guinea pig maximisation test, the test item (36 % a.i. aqueous solution) produced reactions in 6/19 (32 %) of test animals following the initial challenge. In the rechallenge positive reactions were noted in 4/19 (21 %) of the test animals. All four of these animals had responded to the initial challenge (OECD TG 406; EU Method B6).

On the basis of these two studies it is concluded that the test item is not classified as a skin sensitiser, as the level of positive reactions was below 30 % in each study, either after the initial challenge or after the rechallenge.