Butanoic acid, 4-amino-4-oxosulfo-, N-coco alkyl derivs., monosodium salts, compds. with triethanolamine

Endpoint summary

Description of key information

An OECD 406 (Buehler test) skin irritation study was performed and showed no skin sensitisation potential.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

Buehler test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Justification for non-LLNA method:

According to OECD TG 429 the LLNA has several limitations. False positive findings for certain skin irritants may require the use of TG 406.
The test material was tested positive for an irritation potential under guideline OECD 439, 431 and may therefore cause a false positive finding in the LLNA.
Therefore, the Buehler test was chosen as a robust alternative for skin irritating substances compared to the LLNA.

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No. of test material: 0015567151
- Expiration date of the lot/batch: 11 March 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: The stability under storage conditions over the study period was guaranteed by the sponsor.
- Solubility of the test substance in the solvent/vehicle: During initial solubility tests, the suitability of water as vehicle has been displayed by production of a whitish, turbid, foamy formulation appearing visually homogenous at a maximum concentration of 30 % (w/w) after warming (approx. 40 °C) and stirring (magnetic stirrer)

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: test material was diluted in distilled water, warmed up to 40°C while stirring (magnetic stirrer)

FORM AS APPLIED IN THE TEST: Suspension

Species:

guinea pig

Strain:

Dunkin-Hartley

Remarks:

Envigo, NL-5800 AN Venray

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Envigo, NL-5800 AN Venray
- Females nulliparous and non-pregnant: not specified
- Microbiological status of animals: SPF
- Weight at study initiation: 290-330g
- Housing: macrolone cages (approx. 2280 cm²), 2-3 animals/cage, cages and bedding cleaned 3/week, specified enrichment material, filtered air
- Bedding: "Lignocel-Granulat” (Altromin, D-32791 Lage, Lippe), analysis were performed regularly
- Diet: ad libitum
- Water: ad libitum, enriched with vitamin C and acidified with hydrochloric acid to pH 2.5 in order to prevent microbial growth
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20+/-3°C
- Humidity (%): 30%-70%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12h/12h
- IN-LIFE DATES: From: 16 October 2017 To: 12 December 2017

Route:

epicutaneous, occlusive

Vehicle:

water

Remarks:

distilled

Concentration / amount:

30% (w/w)

Day(s)/duration:

6 hour exposure (on day 0, 7, 14)

Adequacy of induction:

highest technically applicable concentration used

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

water

Remarks:

distilled

Concentration / amount:

30% (w/w)

Day(s)/duration:

6 hour exposure

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

control group: 10
test group: 20

Details on study design:

DERMAL PRE-TEST:
- No. of exposures: 4/animal
- Test groups: 3 animals were tested at 4 sites
- Site: left cranial flank, left caudal flank, right cranial flank, right caudal flank
- Duration: 6 hours
- Concentrations: 7.5%, 15%, 22.5%, 30% (w/w)

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Test groups: 1
- Control group: 1
- Site: skin of the left flank
- Frequency of applications: every 7 days

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Test groups: 1
- Control group: 1
- Site: cranial part of the right flank
- Evaluation (hr after challenge): 24

Positive control substance(s):

yes

Remarks:

The last positive control (PC) study with the reference material α-Hexylcinnamaldehyde, technical grade, 85 %, was conducted from September 2017 to October 2017.

Positive control results:

In the positive control test group, 13 of 20 guinea pigs (65 %) reacted with positive skin reactions (erythema grade 1 to 2). One animal of the control group (1/10; 10 %) displayed also an erythema of grade 1 on the skin treated with the PC, but 5 of 20 animals (25 %) of the test group had more intense erythema of grade 2. Therefore, the sensitization potential of the positive reference material was sufficiently proved.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

30% (w/w)

No. with + reactions:

1

Total no. in group:

20

Clinical observations:

In the test group, 1 (animal-No. 20) of 20 animals (5 %) displayed a discrete or patchy erythema 48 hours after the challenge treatment with the 30 % (w/w) test item.

Remarks on result:

no indication of skin sensitisation

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

30% (w/w)

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

All animals of the test group displayed a normal development of body weight with weight increase over the study period and no signs of disturbed general condition.

Remarks on result:

no indication of skin sensitisation

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

All animals of the control group displayed a normal development of body weight with weight increase over the study period and no signs of disturbed general condition.

Remarks on result:

no indication of skin sensitisation

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

All animals of the control group displayed a normal development of body weight with weight increase over the study period and no signs of disturbed general condition.

Remarks on result:

not determinable

Table 1: Observed skin reactions in the control group after the challenge treatment during the main test as well as data of body weight. Challenge treatment: right cranial test field = test item (30 % w/w) in the vehicle distilled water.

	Animal No.	Skin reactions on the right cranial test field after		Body weight in g
		24 hours	48 hours	Day 0	Day 34
Control group	1	0	0	286	504
	2	0	0	293	544
	3	0	0	310	565
	4	0	0	307	534
	5	0	0	288	510
	6	0	0	320	578
	7	0	0	290	520
	8	0	0	326	564
	9	0	0	298	554
	10	0	0	313	570

Table 2: Observed skin reactions in the test group after the challenge treatment during the main test as well as data of body weight. Challenge treatment: right cranial test field = test item (30 % w/w) in the vehicle distilled water.

	Animal No.	Skin reactions on the right cranial test field after		Body weight in g
		24 hours	48 hours	Day 0	Day 34
Test group	11	0	0	308	498
	12	0	0	322	505
	13	0	0	292	530
	14	0	0	304	490
	15	0	0	318	540
	16	0	0	300	502
	17	0	0	301	565
	18	0	0	304	552
	19	0	0	291	540
	20	0	1	321	516
	21	0	0	290	469
	22	0	0	309	548
	23	0	0	302	520
	24	0	0	302	480
	25	0	0	302	513
	26	0	0	306	540
	27	0	0	320	468
	28	0	0	320	512
	29	0	0	308	484
	30	0	0	294	420

Interpretation of results:

GHS criteria not met

Conclusions:

The low incidence of positive skin reactions (5 %) in the test group compared to the reaction-free control group did not supply sufficient evidences for delayed contact sensitization in the guinea pig.
Based on the results of this Buehler test, the test material, was not sensitizing to the skin.

Executive summary:

The dermal sensitizing potential of the test material was investigated by means of the Buehler test.

The main study was performed on 30 guinea pigs in total. A control group of 10 animals and a test group of 20 animals were applied.

The test concentration for the main study was the highest technically achievable homogenous formulation; it was found not cause excessive irritation.

The main study started with an induction phase including an occlusive patch topical application for 6 hours once a week for three consecutive weeks. The animals of the test group were induced with the 30 % (w/w) test material, whereas the animals of the control group were induced with the vehicle distilled water. During the induction phase all animals of both the test group and the control group were free of any reactions.

The low incidence of positive skin reactions (5 %) during challenge of the test group compared to the reaction-free control group did not supply sufficient evidences for delayed contact sensitization in the guinea pig.

Based on the results of this Buehler test, the test material, was not sensitizing to the skin.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The dermal sensitizing potential of the test material was investigated by means of the Buehler test.

The main study was performed on 30 guinea pigs in total. A control group of 10 animals and a test group of 20 animals were applied.

The test concentration for the main study was the highest technically achievable homogenous formulation; it was found not to cause excessive irritation.

The main study started with an induction phase including an occlusive patch topical application for 6 hours once a week for three consecutive weeks. The animals of the test group were induced with the 30 % (w/w) test material, whereas the animals of the control group were induced with the vehicle distilled water.During the induction phase all animals of both the test group and the control group were free of any reactions.

The low incidence of positive skin reactions (5 %) during challenge of the test group compared to the reaction-free control group did not supply sufficient evidences for delayed contact sensitization in the guinea pig.

Based on the results of this Buehler test, the test material, was not sensitizing to the skin.

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 1272/2008. As a result the substance is not considered to be classified for skin sensitization under Regulation (EC) No. 1272/2008.