1-Propanaminium, N,N,N-trimethyl-3-[(2-methyl-1-oxo-2-propen-1-yl)amino]-, 4-C10-13-sec-alkylbenzenesulfonates

Endpoint summary

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:

Between 06 February 2012 and 17 March 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

Housing
The animals were housed either in groups of 2 or individually in polycarbonate containers, the flooring of which was covered with dust-free cuttings and the top fitted a stainless steel lid with a feeding device and drinking device of 500 mL.
The temperature and relative humidity of the main test were controlled to remain within target ranges of 19 to 25°C and 30 to 70%, respectively.
The rate of air exchange was approximately fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (07.00 to 19.00) and twelve hours darkness.
Food and drink
The drinking water (tap water from public distribution system) and food (SDS, FD1) were supplied freely.
Microbiological and chemical analyses of the water were carried out once every six months by IPL Santé Environnement Durables – Atlantique (Bordeaux).
Preparation of animals
Fifteen albino guinea pigs of Dunkin-Hartley strain, supplied by CHARLES RIVER (F-69592 L’ARBRESLE) weighed between 306 g and 351 g at the beginning of the test and were 4 weeks old.
Prior to the test, the animals were kept for a minimum acclimatization period of 5 days, under stabling and nutritional conditions identical to those of the test.
Before the experimentation process, they were identified individually by marking with picric acid and by means of a numbered ring on the edge of one ear.
The animals were carefully shorn before each test item application:
- On the inter-scapular zone for the induction phase,
- On the dorso-lumbar zone for the challenge phase.
At least 3 hours before the first reading (challenge phase) they were shorn a second time in this dorsolumbar zone.
The animals were weighed at the beginning and at the end of the study.
Animal welfare
The study was performed in accordance with the French Animal Protection Law under licence number C 33-122-001.
The animals were provided with suitable environmental enrichment (tunnel).
The study was designed and was conducted to cause the minimum suffering or distress to the animals.

Route:

intradermal and epicutaneous

Vehicle:

other: isotonic sodium chloride

Concentration / amount:

Intradermal induction:
GROUP 1 (Negative control):
2 ID: Freund’s Complete Adjuvant diluted at 50 % in isotonic sodium chloride.
2 ID: isotonic sodium chloride
2 ID: a mixture with equal volumes v/v: Freund’s Complete Adjuvant at 50% and isotonic sodium chloride,
ROUP 2 (Treated):
2 ID: Freund’s Complete Adjuvant diluted by 50 % in isotonic sodium chloride,
2 ID: test item at 0.5% in isotonic sodium chloride,
2 ID: a test mixture in equal volumes v/v : Freund’s Complete Adjuvant at 50% and the test item at 1% in isotonic sodium chloride.

Topical induction:
GROUP 1 (Negative control): 0.5 mL of distilled water.
GROUP 2 (treated): 0.5 mL of the test item at 10% in distilled water.

Challenge
1st Challenge: test item diluted at 1% & 0.625%
2nd Challenge: test item diluted at 2.5%

Route:

epicutaneous, semiocclusive

Vehicle:

other: isotonic sodium chloride

Concentration / amount:

Intradermal induction:
GROUP 1 (Negative control):
2 ID: Freund’s Complete Adjuvant diluted at 50 % in isotonic sodium chloride.
2 ID: isotonic sodium chloride
2 ID: a mixture with equal volumes v/v: Freund’s Complete Adjuvant at 50% and isotonic sodium chloride,
ROUP 2 (Treated):
2 ID: Freund’s Complete Adjuvant diluted by 50 % in isotonic sodium chloride,
2 ID: test item at 0.5% in isotonic sodium chloride,
2 ID: a test mixture in equal volumes v/v : Freund’s Complete Adjuvant at 50% and the test item at 1% in isotonic sodium chloride.

Topical induction:
GROUP 1 (Negative control): 0.5 mL of distilled water.
GROUP 2 (treated): 0.5 mL of the test item at 10% in distilled water.

Challenge
1st Challenge: test item diluted at 1% & 0.625%
2nd Challenge: test item diluted at 2.5%

No. of animals per dose:

10 test
5 control

Details on study design:

Preliminary studies
Determination by intradermal injection of the Maximal Non Necrotizing Concentration (MNNC)
This test was conducted for the purpose of defining a MNNC of the test item which, on intradermic injection during the induction phase, does not risk causing too great a lesion (non-necrotizing concentration), should be well-tolerated systemically and should be the highest to cause mild-tomoderate skin irritation.
One animal received on both sides of the spine, a volume of 0.1 mL of the test item, at 4 concentrations: diluted at 50%, 25%, 10% and 5% in isotonic sodium chloride in view to determine the MNNC.
A macroscopic evaluation of the cutaneous reactions was conducted immediately after injection.
Due to the necrosis observed, a new animal received on both side of the spine a volume of 0.1 mL of the test item at 3 additional concentrations: diluted at 2%, 1% and 0.1% in isotonic sodium chloride.
A macroscopical evaluation of the cutaneous reactions was conducted 24 hours after injections.
Due to the absence of necrosis observed with the concentration of 0.1%, a new animal received on both side of the spine a volume of 0.1 mL of the test item at 3 additional concentrations: diluted at 0.5%, 0.1% and 0.05% in isotonic sodium chloride.
A macroscopical evaluation of the cutaneous reactions was conducted 24 hours after injections.

Determination by topical application of the Pre-Maximal Non Irritant Concentration (Pre-MNIC)
This test, which allowed to evaluate the irritant potential of the test item, defined whether an application of sodium lauryl sulfate would be needed during topical induction phase.
The test item was applied on the dorso-lumbar zone of two guinea pigs shorn beforehand, with occlusive dressing for 24 hours, at 4 different concentrations: 100% diluted at 50%, 25% and 12.5% in distilled water.
A macroscopic evaluation of the cutaneous reactions was conducted 24 hours after removal of the dressing.
Due to the severity of the skin reactions observed with the 4 concentrations, a new animal received in the same experimental conditions, the test item at 4 additional concentrations: diluted at 10%, 5%, 2% and 1% in isotonic sodium chloride.
A macroscopic evaluation of the cutaneous reactions was conducted 24 hours after removal of the dressing.

Determination by topical application of the Maximal Non Irritant Concentration (MNIC)
This test was carried out for the purpose of determining the MNIC of the test item without risk of an irritant effect during the challenge phase.
Three guinea pigs were treated according to the same treatment as animals from GROUP 1 (negative control) for the induction phase (i.e. isotonic sodium chloride and distilled water).
During the challenge phase, the animals were treated with the test item placed onto the selected treatment sites and covered with an occlusive dressing for a period of 24 hours at 4 different concentrations: diluted at 5%, 2.5%, 1.25% and 0.625% in distilled water.
A macroscopic evaluation of the cutaneous reactions was conducted 24 and 48 hours after removal of the occlusive dressing.

Main study
GROUP 1 (negative control) : 5 male guinea pigs identified n° C7148 to C7152
GROUP 2 (treated) : 10 male guinea pigs identified n° C7153 to C7162
Note: The results of the 3 last positive groups (Reference substance: alpha-Hexylcinnamaldehyde Tests 21-23) carried out as method sensibility, are presented in appendix 2 (attachment 2).

Induction phase
1st Intradermal Induction:
Day 0
After shearing the scapular zone, three (3) pairs of intradermal injections (ID) of 0.1 mL were performed on the scapular zone in such a way as an injection on each pair is placed to either side of the spine as follows:
GROUP 1 (Negative control):
2 ID: Freund’s Complete Adjuvant diluted at 50 % in isotonic sodium chloride.
2 ID: isotonic sodium chloride
2 ID: a mixture with equal volumes v/v : Freund’s Complete Adjuvant at 50% and isotonic sodium chloride
GROUP 2 (Treated):
2 ID: Freund’s Complete Adjuvant diluted by 50 % in isotonic sodium chloride,
2 ID: test item at 0.5% in isotonic sodium chloride,
2 ID: a test mixture in equal volumes v/v : Freund’s Complete Adjuvant at 50% and the test item at 1% in isotonic sodium chloride.
2nd Topical Induction:
Day 6: The scapular zone of all the animals in each group was shorn beforehand.
Day 7: A topical application under occlusive dressing for 48 hours was performed on the injection sites of each animal.
GROUP 1 (Negative control): 0.5 mL of distilled water.
GROUP 2 (treated): 0.5 mL of the test item at 10% in distilled water.
Day 9: Occlusive dressing removal
Rest phase
The animals of both groups were left for 10 days.

Challenge phase
Day 20: The experimental procedure of this phase was identical for both groups GROUP 1 (Negative control) and GROUP 2 (Treated) submitted to this experimentation: on the previously shorn dorso-lumbar zone, an application on either side of the spine, under occlusive dressing, was performed during 24 hours: 1 sample cup containing the test item diluted at 1% and 1 sample cup containing the test item at 0.625% (MNIC).
Day 21: Occlusive dressing removal.
Day 28: The experimental procedure of this phase was identical for both groups GROUP 1 (Negative control) and GROUP 2 (Treated) submitted to this experimentation: on the previously shorn dorso-lumbar zone, an application on either side of the spine, under occlusive dressing, was performed during 24 hours: 1 sample cup containing the test item diluted at 2.5% (MNIC).
Day 29: Occlusive dressing removal.

Positive control substance(s):

yes

Remarks:

alpha-Hexylcinnamaldehyde

Positive control results:

See appendix 2 - attachment 2

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

1%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 1%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.625%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.625%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.625%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.625%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

1%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 1%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

1%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 1%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.625%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0.625%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.625%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0.625%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

2.5%

No. with + reactions:

4

Total no. in group:

10

Clinical observations:

1 animal with slight or patchy erythema, 3 animals with moderate confluent erythema and slight oedema

Remarks on result:

other: see Remark

Remarks:

Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 2.5%. No with. + reactions: 4.0. Total no. in groups: 10.0. Clinical observations: 1 animal with slight or patchy erythema, 3 animals with moderate confluent erythema and slight oedema.

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

2.5%

No. with + reactions:

3

Total no. in group:

10

Clinical observations:

1 animal with slight or patchy erythema and slight oedema, 2 animals with moderate confluent erythema and slight oedema

Remarks on result:

other: see Remark

Remarks:

Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 2.5%. No with. + reactions: 3.0. Total no. in groups: 10.0. Clinical observations: 1 animal with slight or patchy erythema and slight oedema, 2 animals with moderate confluent erythema and slight oedema.

Reading:

rechallenge

Hours after challenge:

72

Group:

test chemical

Dose level:

2.5%

No. with + reactions:

3

Total no. in group:

10

Clinical observations:

3 animals with slight or patchy erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 72.0. Group: test group. Dose level: 2.5%. No with. + reactions: 3.0. Total no. in groups: 10.0. Clinical observations: 3 animals with slight or patchy erythema.

Reading:

rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

2.5%

No. with + reactions:

4

Total no. in group:

5

Clinical observations:

3 animal with slight or patchy erythema, 1 animal with moderate confluent erythema

Remarks on result:

other: see Remark

Remarks:

Reading: rechallenge. . Hours after challenge: 24.0. Group: negative control. Dose level: 2.5%. No with. + reactions: 4.0. Total no. in groups: 5.0. Clinical observations: 3 animal with slight or patchy erythema, 1 animal with moderate confluent erythema.

Reading:

rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

2.5%

No. with + reactions:

3

Total no. in group:

5

Clinical observations:

3 animals with slight or patchy erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 2.5%. No with. + reactions: 3.0. Total no. in groups: 5.0. Clinical observations: 3 animals with slight or patchy erythema.

Reading:

rechallenge

Hours after challenge:

72

Group:

negative control

Dose level:

2.5%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 72.0. Group: negative control. Dose level: 2.5%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Interpretation of results An answer over at least 30% of animals is regarded as positive. In accordance with the E.E.C. Directives 93/21 (O.J.E.C.L110 A, May 4th, 1993), 91/325 dated March 5th, 1991 (O.J.E.C. L 180 dated July 8th, 1991) and 67/548, the results obtained for items can be classified according to European regulations concerning the classification, packaging and labelling of dangerous substances: The substances or preparations will be classified as sensitising and characterised by the symbol “Xi” and the danger label “Irritant” with the risk sentence R43 in accordance with the criteria below: R43 : may cause sensitisation by skin contact In accordance with the Regulation (EC) No 1272/2008, the test item will be classified in category 1. The signal word “Warning” and hazard statement H317 “May cause an allergic skin reaction” are required. In accordance with the Regulation (EC) No. 286/2011, the positive test item will be classified in sub-category 1A or 1B in accordance with the following table

	Criteria
Sub-category 1A	≥ 30 % responding at ≤ 0.1 % intradermal induction dose or ≥ 60 % responding at > 0.1 % to ≤ 1 % intradermal induction dose
Sub-category 1B	≥ 30 % to < 60 % responding at > 0.1 % to ≤ 1 % intradermal induction dose or ≥ 30 % responding at > 1 % intradermal induction dose

RESULTS

Concentrations selected

Preliminary studies:

MNNC determination:

No necrosis has been observed, since the concentration of 0.5%. The first induction of the Group 2 has been carried out by intradermal injection at the same concentration of 0.5% (Table 1 - attachment 4).

Pre MNIC determination: 24 hours after the removal of the occlusive dressings, severe erythema associated with moderate oedema was recorded on the treated areas at 100%, 50%, 25% and 12.5% (table 2 - attachment 5).

24 hours after the removal of the occlusive dressings, well defined erythema was recorded on the treated areas at 10% (table 2 - attachment 5).

In view of these results, the concentration selected was 10% for the 2nd induction of the Group 2 and the MNIC determination began at the concentration of 5%.

MNIC determination:

24 and 48 hours after the removal of the occlusive dressings, slight to well defined erythema was recorded on the treated area at 5% (table 3 - attachment 5). This reaction was associated with a slight oedema in one animal on the trated area at 5%. 24 hours after the removal of the occlusive dressings, slight erythema was recorded on the treated area at 2.5% and 1.25%.

In view of this result, the concentrations selected were 1% and 0.625% (MNIC) for the challenge phase.

Main study:

Induction phase Group 2:

The induction phase was performed by intradermal injection on D0 with the test item at 0.5% in isotonic sodium chloride and by topical application on D7 with the test item at 10% in distilled water. No cutaneous reaction was recorded after the 1st induction. During the second induction, dryness was noted in 6 animals (6/10) and scab was noted in 4 animals (4/10), 24 hours after the removal of the occlusive dressing.

Induction phase Group 1:

The induction phase was performed by intradermal injection on D0 with isotonic sodium chloride and by topical application on D7 with distilled water.

No cutaneous reaction was recorded after the induction phase.

1st Challenge phase Groups 1 & 2:

The test item has been used diluted at 1% and 0.625% in distilled water.

2nd Challenge phase Groups 1 & 2:

The test item has been used diluted at 2.5% in distilled water.

Sensitising potential assessment

Overall results of the 1st challenge phase with the test item (readings at 24 and 48 hours) are given in table 4 (attachment 6).

Individual scores of macroscopic evaluations performed during 1st challenge phase with the test item are given in table 5 (attachment 7).

No cutaneous reaction attributable to allergy was recorded in animals from the treated group after the challenge phase, on the treated area with the test item at 1% and 0.625%.

No cutaneous intolerance reaction was recorded in animals from the negative control group after the challenge phase, on the treated area with the test item at 1% and 0.625%.

At the request of the sponsor, a rechallenge phase was carried out with the test item diluted at 2.5% in distilled water after a rest phase of 7 days.

Overall results of the 2nd challenge phase with the test item (readings at 24, 48 and 72 hours) are given in table 6 (attachment 8).

Individual scores of macroscopic evaluations performed during 2nd challenge phase with the test item are given in table 7 (attachment 9).

In the treatment group (treatment dose of 2.5%), it was recorded a slight to well defined erythema in 40% (4/10), 30% (3/10) and 30% (3/10) of the animals from the treated group, 24, 48 and 72 hours respectively after the challenge phase, on the treated area. These reactions were associated with a slight oedema in 30% (3/10) of the animals at the reading time 24 and 48 hours.

In the control group (associated with the treatment dose of 2.5%), It was recorded a slight to well defined erythema in 80% (4/5) and 60% (3/5) of the animals from the control group 24 and 48 hours respectively after the challenge phase, on the area challenged with the test item at 2.5%.

The severity of the reaction was similar in the treated group versus the control group (1.0, 0.8 and 0.3 at the reading times 24, 48 and 72 hours in the treated group respectively versus 1.0 and 0.6 at the reading times 24 and 48 hours in the control group)

As irritation was observed in the control group in almost all animals (3/5), this indicates that the concentration of 2.5% was a minimally irritating concentration rather than non-irritating like 1%.

So, the results of the 1st challenge at the non irritating concentrations (i.e. 1% and 0.625%) were taken for the evaluation of the skin sensitizing properties of the test item.

Weight evolution

The weight growth of negative control animals (Group 1) and treated animals (Group 2) is respectively presented in tables 8 and 9 (attachment 10).

Not any abnormality was recorded in the body weight gain of both groups.

Mortality

No mortality was registered during the main test.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

In view of these results, under these experimental conditions, the test item 1-Propanaminium, N,N,N-trimethyl-3-[(2-methyl-1-oxo-2-propen-1-yl)amino]-,4-C10-13-sec-alkylbenzenesulfonates must not be classified, according to the criteria for classification, packaging and labelling of dangerous substances and preparations in compliance with the E.E.C. Directives 67/548, 2001/59 and 99/45. No symbol or risk phrase is required.
In accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures, the test item must not be classified. No hazard statement or signal word is required.

Executive summary:

Introduction

The aim of the study was to evaluate the possible allergenic activity of the test item after intradermal and topical administration in guinea pigs.

Method

After induction (intradermic injection at 0.5% and topical application at 10%) of 10 Guinea Pigs of treated group with the test item 1-Propanaminium, N,N,N-trimethyl-3-[(2-methyl-1-oxo-2-propen- 1-yl)amino]-, 4-C10-13-sec-alkylbenzenesulfonates and a 10-day rest phase, the challenge phase, under occlusive dressing for 24 hours, consisted to a single topical application of the test item diluted at 1% and 0.625% in distilled water. The experimental protocol was established according the OECD guideline No. 406 dated July 17th, 1992 and the test method B.6 of the council regulation No. 440/2008.

Results

No cutaneous reaction attributable to allergy was recorded in animals from the treated group after the challenge phase, on the treated area with the test item at 1% and 0.625%.

No cutaneous intolerance reaction was recorded in animals from the negative control group after the challenge phase, on the treated area with the test item at 1% and 0.625%.

At the request of the sponsor, a rechallenge phase was carried out with the test item diluted at 2.5% in distilled water after a rest phase of 7 days

In the treatment group (treatment dose of 2.5%), it was recorded a slight to well defined erythema in 40% (4/10), 30% (3/10) and 30% (3/10) of the animals from the treated group, 24, 48 and 72 hours respectively after the challenge phase, on the treated area. These reactions were associated with a slight oedema in 30% (3/10) of the animals at the reading time 24 and 48 hours.

In the control group (associated with the treatment dose of 2.5%), It was recorded a slight to well defined erythema in 80% (4/5) and 60% (3/5) of the animals from the control group 24 and 48 hours respectively after the challenge phase, on the area challenged with the test item at 2.5%.

The severity of the reaction was similar in the treated group versus the control group (1.0, 0.8 and 0.3 at the reading times 24, 48 and 72 hours in the treated group respectively versus 1.0 and 0.6 at the reading times 24 and 48 hours in the control group)

As irritation was observed in the control group in almost all animals (4/5), this indicates that the concentration of 2.5% was a minimally irritating concentration rather than non-irritating like 1%.

So, the results of the 1st challenge at the non irritating concentrations (i.e. 1% and 0.625%) were taken for the evaluation of the skin sensitizing properties of the test item.

Conclusion

In conclusion, in view of these results, under these experimental conditions, the test item 1-Propanaminium, N,N,N-trimethyl-3-[(2-methyl-1-oxo-2-propen-1-yl)amino]-, 4-C10-13-secalkylbenzenesulfonates must not be classified, according to the criteria for classification, packaging and labelling of dangerous substances and preparations in compliance with the E.E.C. Directives 67/548, 2001/59 and 99/45. No symbol or risk phrase is required. In accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures, the test item must not be classified. No hazard statement or signal word is required.

In accordance with the Regulation EC No. 1272/2008 on classification, labelling and packaging of substances and mixtures, the test item must not be classified. No hazard statement or signal word is required.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The methacrylate structures MAPTA and MAPDA are suspect for sensitisation via protein conjugation via Michael addition on conjugated systems with electron withdrawing groups. Also there is a positive result reported on skin sensitization on MAPDA.

Alkyl benzenesulphonates are irritating surface active substances, a group for which the LLNA is known to result to false positive results. Testing on the saltof C10-13-alkylbenzene sulfonate with 3-(methacrylamidopropyl) trimethylammonium (MAPTA-ABS salt) was therefore done according to the GPMT (OECD 406).

 

The study was performed according to OECD 406 guidelines involving 10 test and 5 control Guinea pigs. Studies with positive control α-Hexylcinnamaldehyde confirm the adequate performance of the assay. The test substance was formulated in isotone NaCl for intra-dermal application, and in distilled water for the topical applications. Pre-testing was performed in order to select appropriate concentrations. Maximum non-necrotising concentration to be used for the intradermal injections was determined to be 0.5%, as concentrations of1% resulted to necrosis. Exposure for 24 hour under occlusion a concentration of 10% resulted to sufficient irritation characterised by well defined erythema grade 2 and was selected for topical induction. As maximal non-irritating concentration for challenge 1% was chosen as 24 hours after the removal of the occlusive dressings, as slight erythema was recorded on the treated area at 2.5% and 1.25% in one of three animals. Due to dubious character of this response, an additional challenge concentration of 2.5% was also included.

Challenge with 1% and 0.625% did not result to reaction in any of the test or control animals. Subsequent an rechallenge with 2.5% was applied. This resulted to reactions in 40% of the animals in the test group and in 80% of the control group, indicating that 2.5% concentration was a minimally irritating concentration.

Consequently, as the sensitisation rate was a clear 0% further testing on additional animals was not considered necessary.

Migrated from Short description of key information:
A GPMT assay (OECD 406) resulted to 0% sensitised animals and thus the substance is considered not sensitising to skin.

Justification for selection of skin sensitisation endpoint:
Only study available.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

The likelihood for exposure via inhalation and thus becoming sensitised to this substance, is very low, based on the high boiling point (> 300 °C) and very low vapour pressure (< 0.00000084 Pa at 20°C).

As chemical respiratory sensitisers also elicit positive results in predictive tests for contact sensitisation, the negative outcome for dermal sensitisation is also predictive for non respiratory sensitisation of the substance.

Justification for classification or non-classification

In view of the clear results from the GPMT showing a 0% sensitisation rate, the substance must not be classified for dermal sensitisation.