1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-(C16-18(even numbered) and C18 unsaturated acyl) derivs., hydroxides, inner salts

Endpoint summary

Description of key information

There is 1 study available on the read across substance source 1 which was assessed in the read across justification document attached in section 13.2 of the IUCLID dossier.

This study indicates that the source 1 substance is not skin 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:

weight of evidence

Study period:

From 12th August to 12th December 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study without restrictions

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)

Remarks:

n° 2012/96, 10h January 2013

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

An existing Beuhler study already existed and it was considered un-ethical to re-run the study to a different test guideline taking into account animal welfare.

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories France, L’Arbresle, France
- Age at study initiation: 1 to 2 months old
- Weight at study initiation: males: 307 g (range: 272 g to 330 g) / females: 303 g (range: 284 g to 332 g)
- Housing: in polycarbonate cages with stainless steel lids (Tecniplast 2000P High, 2065 cm²) containing autoclaved sawdust (SICSA, Alfortville, France). Hut was given as enrichment. The animals were group housed in twos, from the same sex and group during the preliminary study, and the animals of the main test were group housed in twos or threes, from the same sex and group.
- Diet (e.g. ad libitum): free access to R14C pelleted maintenance diet, batch No. 13072, (SAFE, Augy, France)
- Water (e.g. ad libitum): free access to tap water (filtered with a 0.22 µm filter).
- Acclimation period: the animals were acclimated to the study conditions for a period of at least 5 days before treatment (groups 1 to 7) or for a period of 2 days (group 8).

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): approximately 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12 h/12 h

IN-LIFE DATES: From: 20 August 2013 To: 20 November 2013

Route:

intradermal and epicutaneous

Vehicle:

other: intradermal injection: propylene glycol/0.9% NaCl (30/70, v/v); topical induction: Ethanol/water for injection (80/20, v/v); challenge: propylene glycol

Concentration / amount:

main test:
Intradermal induction: 0.025%
topical induction: 25%
Firs challenge: 25%
Second challenge: 10%

Route:

epicutaneous, occlusive

Vehicle:

other: intradermal injection: propylene glycol/0.9% NaCl (30/70, v/v); topical induction: Ethanol/water for injection (80/20, v/v); challenge: propylene glycol

Concentration / amount:

main test:
Intradermal induction: 0.025%
topical induction: 25%
Firs challenge: 25%
Second challenge: 10%

No. of animals per dose:

Preliminary assay: 5 groups of 2 animals/sex were tested during the preliminary assay in order to determine the test item concentrations to be used in the main test (see preliminary assay design in table 7.4.1/1).
Main assay: 2 control groups (one primary and one additional control group): 5 animals/sex; 1 tested group: 10 animals/sex

Details on study design:

RANGE FINDING TESTS:

5 groups of animals (2 animals/sex) were tested in order to determine the concentrations used in the main test (see table 7.4.1/1 for preliminary test design).
Due to the severity of whitish or blackish areas at intradermal injection sites observed in all group 1 animals treated at 5, 10 and 25%, decision was taken to euthanize them prematurely for ethical grounds on day 4. No other unscheduled deaths occurred during the preliminary tests.
No clinical signs indicative of systemic toxicity were observed in any animals.
Marked local reactions (whitish or blackish areas) were observed in the interscapular region of all males and females when treated at concentrations of 0.1, 0.25, 0.5, 1, 2.5, 5, 10 or 25% at the 24 and/or 48 hour readings.
At the concentration of 0.05%, blackish areas were noted in 3/4 animals at the 24 and/or 48-hour readings whereas one male showed a slight to moderate erythema only, with or without FCA, throughout the observation period.
At 0.005, 0.01 and 0.025 %, with or without FCA, a slight to mild skin erythema was observed in all males and females at the 24 and/or 48-hour readings. Erythema generally persisted on day 7 and was associated with scab in most cases. In addition, small areas (≤ 0.2 mm in diameter), described as blackish at the 24-hour reading and then as purplish 2 hours later, were recorded in 2/4, 4/4 and 3/4 animals at 0.025%, 0.01 % and at 0.005%, respectively, without FCA. Since the small purplish areas suggested a mechanical injury at the injection site rather than severe cutaneous reactions and according to the criteria for the selection of concentrations described in the OECD 406, the concentration selected for intradermal injections of the main test was 0.025%.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3 (Top, Middle, Down) x2 sites for intradermal injection, one for the topical induction
- Exposure period: d1-d8. d1: intradermal injection / d8: topical induction
- Test groups:
Intradermal induction: Three pairs of injections were given so that one of each pair lies on each side of the midline. The first and second pairs of injections were given close to each other and nearest the head, while the third pair was given towards the caudal part of the test area.
Injection 1 / Top: FCA/0.9% NaCl (50/50, v/v)
Injection 2 / Middle: Test item in vehicle
Injection 3 / Down: Test item (w/v) in FCA/0.9% NaCl (50/50, v/v)
Topical induction: As in the preliminary test, the highest well-tolerated concentration was shown to be non irritant after topical application, 0.5 mL of sodium lauryl sulfate at the concentration of 10% (w/w) in vaseline was applied to the induction site on day 7 (all animals) in order to induce a local irritation. On day 8, a filter paper (approximately 8 cm2) was fully-loaded with the dose formulations, and then applied to the clipped interscapular region, over the intradermal injection sites. The filter paper was held in place by means of an occlusive dressing for 48 hours.
- Control group:
Intradermal induction: Three pairs of injections were given so that one of each pair lies on each side of the midline. The first and second pairs of injections were given close to each other and nearest the head, while the third pair was given towards the caudal part of the test area.
Injection 1 / Top: FCA/0.9% NaCl (50/50, v/v)
Injection 2 / Middle: vehicle
Injection 3 / Down: vehicle at 50% in FCA/0.9% NaCl (50/50, v/v)
Topical induction: As in the preliminary test, the highest well-tolerated concentration was shown to be non irritant after topical application, 0.5 mL of sodium lauryl sulfate at the concentration of 10% (w/w) in vaseline was applied to the induction site on day 7 (all animals) in order to induce a local irritation. On day 8, a filter paper (approximately 8 cm2) was fully-loaded with the vehicle, and then applied to the clipped interscapular region, over the intradermal injection sites. The filter paper was held in place by means of an occlusive dressing for 48 hours.
- Site: interscapular region
- Frequency of applications: Topical induction 8 days after intradermal one
- Duration: Acute (intradermal) / 48 h (topical)
- Concentrations: intradermal injection:0.025% TS, contact sensitisation: 25% TS.

B. CHALLENGE EXPOSURE
- No. of exposures: 2
- Day(s) of challenge: Day 22 and Day 33
- Exposure period: 24 hours
- Test groups: TS vs vehicle
- Control group: TS vs vehicle
- Site: 1st challenge: posterior flank; 2nd challenge: median flank
- Concentrations: 1st challenge: 25%; 2nd challenge: 10%
- Evaluation (hr after challenge):1st and 2nd challenge: evaluation at 24; 48 and 72 hrs after patch removal

OTHER:
- pH values of dose formulations without FCA retained for the study were measured before to be used for intradermal injections. The values were comprised between 5 and 6.

Challenge controls:

Group 8: Animals (5/sex) received nothing until day 33 (no intradermal injection, no topical induction, no first challenge). On day 33 (2nd challenge), animals were treated as the oher animals (groups 6 and 7): on the right meadian flank, application of a patch with vehicle whereas on the left median flank, application of a pacth with the test item at 10% in the vehicle (propylene glycol).

Positive control substance(s):

yes

Remarks:

The sensitivity and reliability of the experimental technique is assessed every 6 months by performing the test with Benzothiazole-2-thiol a known skin sensitiser (30% of positive responses are expected).

Positive control results:

A control of the sensitivity of guinea pigs to a reference item (Marcaptobenzothiazole) was performed in May 2013 (CIT/study No. 40163 TSG). The Magnusson and Kligman method was followed with 5 control animals and 10 treated animals. The reference item induced positive skin sensitisatio in 90% (9/10) guinea pigs.
The test is therefore considered sensitive.

Reading:

other: First challenge 1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

2

Total no. in group:

20

Clinical observations:

discrete erythema

Remarks on result:

other: Reading: other: First challenge 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25%. No with. + reactions: 2.0. Total no. in groups: 20.0. Clinical observations: discrete erythema.

Reading:

other: First challenge 2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

12

Total no. in group:

20

Clinical observations:

discrete and moderate erythema

Remarks on result:

other: Reading: other: First challenge 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25%. No with. + reactions: 12.0. Total no. in groups: 20.0. Clinical observations: discrete and moderate erythema.

Reading:

other: First challenge 3rd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

25%

No. with + reactions:

15

Total no. in group:

20

Clinical observations:

discrete and moderate erythema

Remarks on result:

other: Reading: other: First challenge 3rd reading. . Hours after challenge: 72.0. Group: test group. Dose level: 25%. No with. + reactions: 15.0. Total no. in groups: 20.0. Clinical observations: discrete and moderate erythema.

Reading:

other: First challenge 1s reading

Hours after challenge:

24

Group:

negative control

Dose level:

25%

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

discrete and moderate erythema

Remarks on result:

other: Reading: other: First challenge 1s reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 25%. No with. + reactions: 6.0. Total no. in groups: 10.0. Clinical observations: discrete and moderate erythema.

Reading:

other: First challenge, 2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

25%

No. with + reactions:

9

Total no. in group:

10

Clinical observations:

discrete and moderate erythema

Remarks on result:

other: Reading: other: First challenge, 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 25%. No with. + reactions: 9.0. Total no. in groups: 10.0. Clinical observations: discrete and moderate erythema.

Reading:

other: First challenge, 3rd reading

Hours after challenge:

72

Group:

negative control

Dose level:

25%

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

discrete erythema

Remarks on result:

other: Reading: other: First challenge, 3rd reading. . Hours after challenge: 72.0. Group: negative control. Dose level: 25%. No with. + reactions: 6.0. Total no. in groups: 10.0. Clinical observations: discrete erythema.

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

15

Total no. in group:

20

Clinical observations:

discrete and moderate erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 10%. No with. + reactions: 15.0. Total no. in groups: 20.0. Clinical observations: discrete and moderate erythema.

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

10%

No. with + reactions:

17

Total no. in group:

20

Clinical observations:

discrete and moderate erythema with occasional edema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 10%. No with. + reactions: 17.0. Total no. in groups: 20.0. Clinical observations: discrete and moderate erythema with occasional edema.

Reading:

rechallenge

Hours after challenge:

72

Group:

test chemical

Dose level:

10%

No. with + reactions:

6

Total no. in group:

20

Clinical observations:

discrete erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 72.0. Group: test group. Dose level: 10%. No with. + reactions: 6.0. Total no. in groups: 20.0. Clinical observations: discrete erythema.

Reading:

rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

10%

No. with + reactions:

8

Total no. in group:

10

Clinical observations:

discrete and moderate erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 24.0. Group: negative control. Dose level: 10%. No with. + reactions: 8.0. Total no. in groups: 10.0. Clinical observations: discrete and moderate erythema.

Reading:

rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

10%

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

discrete and moderate erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 10%. No with. + reactions: 6.0. Total no. in groups: 10.0. Clinical observations: discrete and moderate erythema.

Reading:

rechallenge

Hours after challenge:

72

Group:

negative control

Dose level:

10%

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

discrete erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 72.0. Group: negative control. Dose level: 10%. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: discrete erythema.

Reading:

rechallenge

Hours after challenge:

24

Group:

other: naive control group (group 8)

Dose level:

10%

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

discrete and moderate erythema with occasional edema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 24.0. Group: other: naive control group (group 8). Dose level: 10%. No with. + reactions: 6.0. Total no. in groups: 10.0. Clinical observations: discrete and moderate erythema with occasional edema.

Reading:

rechallenge

Hours after challenge:

48

Group:

other: naive control group (group 8)

Dose level:

10%

No. with + reactions:

8

Total no. in group:

10

Clinical observations:

discrete and moderate erythema with occasional edema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 48.0. Group: other: naive control group (group 8). Dose level: 10%. No with. + reactions: 8.0. Total no. in groups: 10.0. Clinical observations: discrete and moderate erythema with occasional edema.

Reading:

rechallenge

Hours after challenge:

72

Group:

other: naive control group (goup 8)

Dose level:

10%

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

discrete erythema

Remarks on result:

other: Reading: rechallenge. . Hours after challenge: 72.0. Group: other: naive control group (goup 8). Dose level: 10%. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: discrete erythema.

Group:

positive control

Remarks on result:

not measured/tested

No unscheduled deaths occurred during the main test. No clinical signs indicative of systemic toxicity were observed in any animals.

Scabs were observed in all group 6 (control) and 7 (treated) animals at the intradermal injection sites during the observation period, generally associated with cracks and/or wounds. These signs were not attributed to treatment with the test item, but to the administration route. In addition, an abscess was noted in 1/10 control group 6 animals between days 16 and 19. No local reactions were observed in any control group 8 animals.

The body weight of animals was unaffected by the test item treatment.

Table 7.4.1/2: Results of the main test

Group

First challenge (day 22)

Second challenge (day 33)

Flank exposed to vehicle

Flank exposed to test item

Flank exposed to vehicle

Flank exposed to test item

24 h

48 h

72 h

24 h

48 h

72 h

24 h

48 h

72 h

24 h

48 h

72 h

6 (primary control)

1/10 [1]

1/10 [1]

0/10

6/10 [1-2]

9/10 [1-2]

6/10 [1]

0/10

1/10 [1]

0/10

8/10 [1-2]

6/10 [1-2]

1/10 [1]

8 (additional control)

1/10 [1]

0/10

0/10

6/10 [1-2]*

8/10 [1-2]*

1/10 [1]

7 (treated)

0/20

2/20 [1]

2/20 [1]

2/20 [1]

12/20 [1-2]

15/20 [1-2]

4/20 [1]

0/20

1/20 [1]

15/20 [1-2]

17/20 [1-2]*

6/20 [1]

Erythema grade indicated between brackets (1 = discrete, 2 = moderate)

* with occasional edema

Microscopic examination:

Slight epidermal and upper dermal changes were noted on the left flank (treated with test item) compared to the right flank (treated with vehicle) affecting several males and females from all groups, and were suggestive of skin irritancy.

Right Flank (treated with vehicle)

 

Findings on the right flank were similar in animals from all groups. Incidence and severity were comparable although animals in control group 8 were slightly less affected. The severity of these findings was minimal in most of the animals.

Mononuclear cell infiltration of the upper dermis was noted on the right flank from a large proportion of males and females. This change was frequently accompanied by mononuclear cell infiltration (including vacuolated macrophages) in the deep dermis and in the subcutaneous tissue. Eosinophil infiltration was observed in the upper dermis from several males and females. Hyperkeratosis was noted only in animals from groups 6 (control) and 7 (treated) as other occasional findings that consisted in serocellular crusts (also in 2/5 males from control group 8), ulceration/erosion, upper dermis edema, spongiosis and acanthosis.

Extravascular red blood cells in the upper dermis (described as hemorrhage) and granulocytic infiltration were noted in a single female from treated group 7.

 

Left Flank (treated with test item)

 

Group 6 (control)

In addition to the changes seen on the right flank, there was a marginal increased incidence in edema, spongiosis and serocellular crusts. Extravascular red blood cells in the upper dermis (described as hemorrhage) were noted in a couple of males and intraepidermal cellular debris/inflammatory cells were found in three animals.

In one of those animals, an intraepidermal vesicle was found filled with granulocytes along with epidermal erosion. Granulocytic infiltration was also present in the underlying dermis. In another animal, erosion was also found together with granulocytic infiltration and intraepidermal cellular debris/inflammatory cells. These findings were indicative of irritation.

 

Group 7 (treated)

Compared to the right flank, there was a minimal increased incidence of mononuclear cell infiltration in the upper and deep dermis in males and females from group 7.

This was accompanied by an increased incidence and/or severity of extravascular red blood cells in the upper dermis (described as hemorrhage), acanthosis, spongiosis, hyperkeratosis, serocellular crusts, ulceration/erosion and/or intraepidermal cellular debris/inflammatory cells/vacuoles.

In 3/10 males and 2/10 females, all these changes were also found on the right flank and suggested a skin irritation.

 

Group 8 (naive control)

In addition to the changes observed on the right flank, upper dermis edema, hemorrhage, spongiosis, hyperkeratosis, serocellular crusts and/or intraepidermal cellular debris/inflammatory cells were seen in several males and females. Incidence of dermal granulocytic infiltration was higher than in the other groups although no ulcerations/erosions were seen. One male had slightly more pronounced changes including slight dermal edema and hemorrhage that were suggestive of skin irritation.

Most of the changes seen on the right flank (vehicle) were also observed with increased incidence and severity on the left flank (test item) from several animals. These similarities suggested they were related to the technical procedure. Inter-individual variability was noted in all groups, a few animals being more affected than the others and some left flanks being comparable to right flanks. The increased incidence and/or severity on the left flank were considered to be related to the application of the test item.

A spectrum of changes suggestive of skin irritancy was observed on the left flank of several animals from group 6, 7 and 8. These changes consisted in variable degrees and incidence of dermal mononuclear cell and granulocytic infiltration, dermal edema, occasional dermal hemorrhage, erosion/ulceration of the epidermis, hyperkeratosis, serocellular crusts, acanthosis and spongiosis. Cellular debris often accompanied with inflammatory cells, vacuoles or red blood cells were also found in the epidermis.

On the left flank, changes were similar in animals that had already been treated with the test-item by cutaneous application or by intradermal injection (groups 6 or 7) compared to animals that had never been treated with the test-item before (group 8).

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the experimental conditions of this study, the test item, Erucic Amidopropyl Betaine, did not induce delayed contact hypersensitivity in guinea pigs.

Executive summary:

In a Guinea-Pig Maximisation Test performed according to the OECD No. 406 test guideline, Erucic Amidopropyl Betaine (purity of 87%) was tested for its skin sensitising potential in Hartley male and female guinea pigs.  

A preliminary test on 5 groups of animals (2/sex) using intradermal injections of the test substance in vehicle (propylene glycol/0.9% NaCl (30/70, v/v)) or Freund's complete adjuvant (FCA) at concentration from 0.005 to 25% showed that higher concentration than 0.025% induced severe skin irritation. At 0.005, 0.01 and 0.025 %, with or without FCA, a slight to mild skin erythema was observed in all males and females at the 24 and/or 48-hour readings. Erythema generally persisted on day 7 and was associated with scab in most cases. The concentration selected for intradermal injections of the main test was therefore 0.025%.

During this preliminary assay, the local reactions following a topical application of the test item at 10 and 25% in Ethanol/water for injection (80/20, v/v) (in the condition of the induction phase) or propylene glycol (in the condition of challenge phase) were assessed. In ethanol/water, no cutaneous reactions were observed in any animals treated at 10 and 25%. Therefore, the concentration of 25% was selected for the topical application of the induction phase (day 8). In propylene glycol, no cutaneous reactions were observed in any animals treated at 10 and 25%, except dryness of the skin at the 48-hour reading in one female given 10% and in both males given 25%. Therefore, the concentration selected for the challenge application (day 22) was 25%. For the second challenge application (day 33), the test concentration was lowered down to 10% in order to reduce the possible irritation by the test item.

In the main test, 2 control groups (5 animals/sex) and one tested group (10 animals/sex) were used. Group 6 corresponded to the negative control group whereas group 8 corresponded to a naive challenge control group.

For the induction phase, on day 1, the dose formulations were administered by intradermal injection in the clipped interscapular region. Three pairs of injections were given:

- Injection 1: FCA/0.9% NaCl (50/50, v/v) in the negative control and the test groups

- Injection 2: Vehicle in the control group; Test item in the tested group

- Injection 3: Vehicle at 50% (w/v) in FCA/0.9% NaCl (50/50, v/v) in the control group; Test item (w/v) in FCA/0.9% NaCl (50/50, v/v) in the tested group.

As in the preliminary test, the highest well-tolerated concentration was shown to be non‑irritant after topical application, 0.5 mL of sodium lauryl sulfate at the concentration of 10% (w/w) in vaseline was applied to the induction site on day 7 (all animals) in order to induce a local irritation. On day 8 a filter paper was fully-loaded with the dose formulations, and then applied to the clipped interscapular region, over the intradermal injection sites. The filter paper was held in place by means of an occlusive dressing for 48 hours. Control animals received the vehicle (ethanol/water for injection (80/20, v/v)) only. Two challenges were performed on day 22 and 33 by applying a patch with the test item in the vehicle under occlusive condition during 24hrs.Observation and grading of skin reactions were performed 24, 48 and 72 hours after patch removal to assess potential sensitisation. Microscopic examinations were performed to help conclude on the skin reactions observed: skin samples of the second challenge application sites were taken (sites treated with test item or vehicle alone).

Following the first challenge, cutaneous reactions recorded in the treated group animals challenged with the test item at 25% in popylene glycol were of lower incidence and severity than those observed in the control group animals at the 24 (10 and 60%, respectively) and 48 (60 and 90%, respectively) ‑hour readings. At the 72-hour reading, 20% of the treated group animals (4/20) showed positive responses (moderate erythema) compared with control group animals (0%). According to the criteria of CLP Regulation, this incidence was below the classification threshold of the test item as skin sensitizer. The cutaneous reactions were attributed to the irritant properties of the test item.

Following the second challenge, discrete erythema recorded in the treated group animals challenged with the test item was of lower or same incidence than that observed in control groups (vehicle control induction group, and naive group) animals at 24- and 48-hour readings but was of higher incidence at 72-hour reading (30% vs.10% in control groups animals). According to the criteria of CLP Regulation, this difference was below the classification threshold of the test item as skin sensitizer.

Moderate erythema observed in the treated group animals challenged with the test item was of lower incidence than that noted in the vehicle induced control group animals at 24-hour reading but was of higher incidence at 48‑hour reading (45% vs. 30% in group control animals). According to the criteria of CLP Regulation, this difference was below the classification threshold of the test item as skin sensitizer. In addition, as moderate erythema did not persist at the 72-hour reading and edema was only observed at the 48-hour reading, these signs were not considered to be related to contact delayed hypersensitivity. They rather suggested irritant effects of the test item. Therefore, the cutaneous reactions were attributed to the irritant properties of the test item.

This was confirmed by the microscopic examination which revealed that changes observed on the flanks exposed to vehicle or test item were similar in nature and may be attributed to the technical procedure. When compared to the flank treated with vehicle, increased incidence and/or severity of changes noted on the flank treated with test item in several animals was related to test item application but all microscopic changes, mainly consisting of dermal mononuclear cell and granulocytic infiltration, dermal edema or hemorrhage, erosion/ulceration of epidermis, hyperkeratosis, serocellular crusts, acanthosis and spongiosis, were suggestive of skin irritation rather than contact delayed hypersensitivity, corroborating the in-life phase conclusions.

Therefore, under the conditions of this test, Erucic Amidopropyl Betaine, did not induce delayed contact hypersensitivity in guinea pigs and is therefore not classified for skin sensitisation according to the criteria of the Regulation (EC) 1272/2008 (CLP) and the Directive 67/548/EEC (DSD). This study is considered as acceptable and satisfies the requirement for skin sensitization endpoint.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Boundary composition.001 (Composition of C18:1 amidopropyl betaine containing≥0.1% and < 10% C18:1 amidopropyl amide)

The target substance (TS) is classified as H317: May cause an allergic skin reaction, according to Commission Regulation (EU) No 286/2011 of 10 March 2011 (second amendment of CLP regulation) due to the presence of a sensitising impurity (N-[3-(dimethylamino)propyl]aleamide, CAS#109-28-4, EC#203-661 -5

) above its classification limit. This classification result was considered as part of the chemical safety assessment.

 

Boundary composition.002 (Composition of C18:1 amidopropyl betaine containing < 0.1% C18:1 amidopropyl amide)

The target substance (TS) is not classified for skin sensitization, according to Commission Regulation (EU) No 286/2011 of 10 March 2011 (second amendment of CLP regulation), based on the test data for the source 1 substance