Sodium N-lauroylsarcosinate

Endpoint summary

Description of key information

Skin corrosion in vitro (OECD 431): non-corrosive
Skin irritation in vivo (OECD 404, 30%): not irritating
Skin irritation in vivo (U.S. Federal Hazardous Substances Act, 10% ): not irritating
Eye irritation in vivo (OECD 405, 30%): irritating
Eye irritation in vivo (U.S. Federal Hazardous Substances Act, 10% ): irritating

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

25 Oct - 17 Nov 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

other: LiIttle russian, Chbb:HM(SPF)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: DIMEO Schonwalde GmbH, Schonwalde, Germany and stock Chbb:HM from Charles River Deutschland GmbH, Kisslegg, Germany
- Age at study initiation: approx 13 - 15 months
- Weight at study initiation: 2.5 - 2.6 kg
- Housing: During a pre-period of at least one week and throughout the experiment the rabbits were caged individually in PPO cages (floor area: 2576 cm²) with perforated floor.
- Diet: pelleted complete rabbit diet "Altromin 2123", ad libitum.
- Water: domestic quality drinking water acidified with hydrochloric acid to pH 2.5 in order to prevent microbial growth, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 55 ± 15
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: not required, untreated sites of the same animal served as control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): 30% in water

Duration of treatment / exposure:

Initial test: 3 min, 1 and 4 h
Confirmatory test: 4 h

Observation period:

14 days
Reading time points: 1, 24, 48 and 72 h

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: anterior area of the animal
- Type of wrap if used: The patch was placed on the appropriate anterior test field and secured semi-occlusively with adhesive Gothaplast tape (2.5 cm).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After the exposure time the patch was removed, the test field was marked and the treated skin was cleaned with mild soap and lukewarm water.
- Time after start of exposure:
Initial test: 3 min, 1 h and 4 h
Confirmatory test: 4 h

SCORING SYSTEM: Draize scoring system

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: 30% (v/v) in water

Irritation parameter:

erythema score

Basis:

animal: #2 and #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: 30% (v/v) in water

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: 30% (v/v) in water

Irritation parameter:

edema score

Basis:

animal: #2 and #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Remarks on result:

other: 30% (v/v) in water

Irritant / corrosive response data:

Initial test:
The animal showed a well defined erythema on the posterior right test field immediately after the application.

Main test:
1 h after the termination of exposure a well defined erythema was observed on the posterior right test field of animal No. 2784. Animals No. 2865 and No. 2866 showed a very slight erythema on the anterior right test fields. 24, 48 and 72 h after the termination of exposure a very slight erythema was observed on the middle right test field of animal No. 2784 as well as a moderate to severe erythema and a very slight oedema on the posterior right test field. Animals No. 2865 and No. 2866 showed a very slight erythema on the anterior right test field. 7 days after the termination of exposure large scales were still observed on the whole posterior right test field of animal No. 2784. Animals No. 2865 and No. 2866 still showed isolated scales on the whole anterior right test fields.
14 days after the termination of exposure animals No. 2784, No. 2865 and No. 2866 were free of any signs of skin irritation.

Other effects:

No further local or systemic effects were reported.

Table 1. Results of the initial irritation study.

Exposure time	Erythema formation observed [h]					Oedema formation observed [h]
	0	1	24	48	72	0	1	24	48	72
3 min	0	0	0	0	0	0	0	0	0	0
1 h	0	0	1	1	1	0	0	1	1	1

Table 2. Results of skin irritation study.

Observation time	Rabbit no.
	1		2		3
	Erythema	Edema	Erythema	Edema	Erythema	Edema
1 h	2	0	1	0	1	0
24 h	3	1	1	0	1	0
48 h	3	1	1	0	1	0
72 h	3	1	1	0	1	0
Mean value 24 + 48 + 72 h	3,00	1,00	1,00	0,00	1,00	0,00

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation(EC) No. 1272/2008

Conclusions:

CLP: not classified

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

21 Oct - 23 Oct 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Version / remarks:

(adopted 13 April 2004)

Deviations:

no

GLP compliance:

yes

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Episkin

Vehicle:

unchanged (no vehicle)

Details on test system:

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: at room temperature

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: At the end of each exposure period, each tissue was removed from the well using forceps and rinsed using a wash bottle containing Phosphate Buffered Saline Dulbeccos (PBS) with Ca++and Mg++. Rinsing was achieved by filling and emptying each tissue insert for approximately 40 seconds using a constant soft stream of PBS to gently remove any residual test material.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 0.3 mg/mL
- Incubation time: 3 h ± 5 min
- Spectrophotometer: Anthos 2001 microplate reader
- Wavelength: OD540

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
A test material may interfere with the MTT endpoint, if it was able to directly reduce MTT and at the same time was present on or in the tissues when the MTT viability test was performed. To identify this possible interference, the test material was checked for the ability to directly reduce MTT.

PREDICTION MODEL / DECISION CRITERIA
Please refer to Interpretation of Results under "any other information materials and methods incl. tables".

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied: 20 mg of the solid test material was applied topically to the corresponding tissues ensuring uniform coverage of the tissues. 100 µl of 0.9% w/v sodium chloride solution was added for wetting of the test material.

NEGATIVE CONTROL
- Amount(s) applied: 50 µL

POSITIVE CONTROL
- Amount(s) applied: 50= µL

Duration of treatment / exposure:

3, 60 and 240 min

Number of replicates:

In duplicates for each treatment duration and controls

Strain:

other: reconstructed human epidermis

Details on test animals or test system and environmental conditions:

Not applicable.

Preparation of test site:

other: intact reconstructed human epidermis

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min

Value:

117.1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 min of exposure

Value:

138.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

240 min of exposure

Value:

138.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: The MTT solution containing the test material did not turn blue/purple. This was taken to indicate the test material did not reduce MTT.
- Colour interference with MTT:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control:
- Acceptance criteria met for positive control: Yes, the relative mean tissue viability for the positive control treated tissues was 10.8%.
- Acceptance criteria met for variability between replicate measurements:

Table 1. Mean OD₅₄₀Values and Viabilities for the Negative Control, Positive Control Material and Test Material.

Material	Exposure Period [min]	Mean OD540of duplicate tissues	Relative mean % viability
Negative Control Material	240	0.158	100*
Positive Control Material	240	0.017	10.8
Test Material	240	0.213	134.8
	60	0.213	134.8
	3	0.185	117.1

*=     The mean viability of the negative control tissues is set at 100%

Table 2. Qualitative Evaluation of Tissue Viability (MTT uptake visual evaluation).

Material	Exposure Period	Tissue 1	Tissue 2
Negative Control Material	240 Minutes	-	-
Positive Control Material	240 Minutes	++	++
Test Material	240 Minutes	-	-
	60 Minutes	-	-
	3 Minutes	-	-

MTT Visual Scoring Scheme of SkinEthic Tissues

-     =  Blue tissue (viable)

++  =  Tissue completely white (dead)

Quality Criteria

The relative mean tissue viability for the positive control treated tissues was10.8% relative to the negative control treated tissues following the 240-minute exposure period. The positive control acceptance criterion was therefore satisfied.

Interpretation of results:

other: the results of this study as a stand-alone study are not suitable for classification according to CLP/EU GHS criteria; the results may be used for classification purposes in a weight of evidence approach

Conclusions:

Under the conditions of the RHE test method the test substance did not show corrosive properties.

Reference 3

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

13 Jul - 16 Jul 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

(Exposure time 24 h and occluded dressing)

Qualifier:

according to guideline

Guideline:

other: The method used meets the requirements of the test for primary irritant substances described in the U.S. Federal Hazardous Substances Act (U.S. Federal Register, 1973, Vol. 38, No. 187, Section 1500: 41)

Deviations:

yes

Remarks:

Exposure time 24 h and occluded dressing.

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: A. Smith, Warlingham, Surrey
- Housing: The rabbits were housed in grid bottomed metal cages.
- Diet: commercially available antibiotic free rabbit diet, ad libitum
- Water: mains drinking water via automatic nozzles in each cage, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-23
- Humidity (%): 48-86
- Air changes (per hr): air conditioned room
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

occlusive

Preparation of test site:

other: shaved and abraded

Vehicle:

water

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): The supplied test material was diluted 1 to 3 to give 10% active material.

Duration of treatment / exposure:

24 h

Observation period:

72 h
Reading time points: 24 and 72 h

Number of animals:

6 females

Details on study design:

TEST SITE
- Area of exposure: The diluted test material was placed, over two 2.5 cm square surgical lint pads attached to a length of 5 cm wide 'sleek' plastic adhesive wrapping. The lint squares were then placed in contact with the animals skin, one lint square in contact with abraded skin and one lint square in contact with intact skin, bilateral to the midline, and secured in position by the attached 'sllek' adhesive tape. The trunk of the animal was then encircled with a length of 'Elastoplast' elastic adhesive bandage 7.5 cm wide.

REMOVAL OF TEST SUBSTANCE
- Washing: After the contact period the occulusive dressings were removed and excess test material remaining on the skin removed by gentle wiping with cotton wool soaked in warm water.
- Time after start of exposure: 24 h

SCORING SYSTEM:
Draize scoring system

Irritation parameter:

erythema score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

1.83

Max. score:

4

Reversibility:

not fully reversible within: 72 h

Remarks on result:

other: no 48 h data are available; for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption: persistence of effects seen at 24 h over 48 h); test substance was tested at 10% (v/v) in water

Irritation parameter:

edema score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

1.06

Max. score:

4

Reversibility:

not fully reversible within: 72 h

Remarks on result:

other: no 48 h data are available; for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption: persistence of effects seen at 24 h over 48 h); test substance was tested at 10% (v/v) in water

Irritant / corrosive response data:

Well defined erythema was observed at both abraded and intact treatment sites of all 6 animals following the 24 h dosing period (see Table 1 under "Any other information on results incl. tables"). Slight oedema was observed at 2 abraded sites and 4 intact treatment sites. Some decline in the irritant response was apparent during the study. 72 h after dosing well defined erythema remained at both treatment sites of 4 animals and in one animal very slight erythema at both treatment sites was apparent. Slight oedema of the treated skin was observed at the abraded skin of one animal and very slight oedematous reaction was observed at three abraded sites and three intact sites.

Other effects:

No further local or systemic effects were reported.

Table 1. Results of skin irritation study (intact skin).

Observation time	Rabbit no.
	1		2		3		4		5		6
	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema
24 h	2	2	2	1	2	2	2	1	2	1	2	1
48 h	No experimental data available; for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption)
72 h	2	0	1	0	2	1	0	0	2	1	2	1

Table 2. Calculation of mean scores.

	Rabbit no.
	1		2		3		4		5		6
	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema
Mean value 24 + 48 + 72 h*	2.00	1.33	1.67	0.67	2.00	1.67	1.33	0,.67	2.00	1.00	2.00	1.00

*No 48 h data are available: for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption: persistence of effects seen at 24 h over 48 h).

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation(EC) No. 1272/2008

Conclusions:

In the present study erythema were not fully reversible within an observation period of 72 h. However, due to the short observation period in this study, and in combination with the declining tendency of the irritating effects, the result of the study was considered to be non-irritating at 10% (v/v).
CLP: not classified

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 Sep - 2 Nov 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

other: SPF albino - Littlerussian

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: DIMED Schonwalde GmbH, Schonwalde
- Age at study initiation: approx. 6-7 months
- Weight at study initiation: 2.4-2.6 kg
- Housing: During a pre-period of at least one week and throughout the study the rabbits were caged individually in PPO cages (floor area: 2576 sq.cm) with perforated floor.
- Diet: A pelleted complete rabbit diet "Altromin 2123" was available, ad libitum.
- Water: The animals had free access to bottles with domestic quality drinking water acidified with hydrochloric acid to pH 2.5 in order to prevent microbial growth, ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 55 ± 15
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

water

Controls:

other: the untreated eye served as control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.1 mL
- Concentration (if solution): 30% (v/v)

Duration of treatment / exposure:

single application without washing

Observation period (in vivo):

72 h
Reading time points: 1, 24, 48 and 72 h and 7, 14 and 21 days

Number of animals or in vitro replicates:

3

Details on study design:

SCORING SYSTEM: Draize scoring system

TOOL USED TO ASSESS SCORE:
Initial test:
The treated eye was examined and the grade of ocular reaction was recorded 1 h and 24 h later. After the 24 h-reading Fluorescein was instilled. After irrigation with 20 mL 0.9 % sodium chloride solution the eye was examined again using UV light to detect possible corneal damage. The eye was also examined 48 h and 72 h after the treatment as well as on day 7 and 14.

Confirmatory Test:
During the confirmatory test the eyes of the animals were likewise examined for ocular reactions 1 h, 24 h, 48 h and 72 h after the application as well as on Day 7, 14 and 21.

Irritation parameter:

cornea opacity score

Basis:

animal: #1 and #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

fully reversible within: 21 days

Irritation parameter:

iris score

Basis:

mean

Remarks:

of all 3 animals

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

of all 3 animals

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 14 days

Irritation parameter:

chemosis score

Basis:

animal: #1 and #2

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.67

Max. score:

4

Reversibility:

fully reversible within: 7 days

Table 1. Results of eye irritation study.

Rabbit #	Time [h]	conjunctivae		iris	cornea		conjunctivae		iris	cornea
		redness	swelling				redness	swelling
1	1 h	3	2	0	1
	24 h	2	2	1	1
	48 h	2	1	1	1
	72 h	2	1	1	1
	average	2.0	1.3	1.0	1.0	Time to reversion	14	7	7	14
2	1 h	2	1	1	1
	24 h	2	2	1	2
	48 h	2	1	1	1
	72 h	2	1	1	1
	average	2.0	1.3	1.0	1.3	Time to reversion	14	7	7	21
3	1 h	2	1	0	1
	24 h	2	2	1	1
	48 h	2	2	1	1
	72 h	2	1	1	1
	average	2.0	1.7	1.0	1.0	Time to reversion	14	7	7	7
	Time [h]	conjunctivae		iris	cornea
		redness	swelling			avg. time to reversion [Days]	14	7	7	14
average score	1	2.33	1.33	0.33	1.00
	24	2.00	2.00	1.00	1.33
	48	1.67	1.33	1.00	1.00
	72	1.67	1.00	1.00	1.00
	24+48+72	1.78	1.44	1.00	1.00

Interpretation of results:

other: Eye irritation 2, H319. Classification according to Regulation (EC) No 1272/2008 (CLP/EU GHS).

Conclusions:

CLP: Eye irrit 2, H319

Executive summary:

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Discussion

Skin irritation

The in vitro skin corrosion properties of Sodium N-lauroylsarcosinate (CAS 137-16-6) were tested in a study according to OECD guideline 431 under GLP conditions using the EPISKIN in vitro Reconstituted Human Epidermis Model (Harlan Laboratories Ltd, 2010b). In the study, the tissues were treated with the unchanged test material for exposure periods of 3, 60 and 240 min. Positive and negative controls were included in the study. The corrosive potential of the test material was predicted from the relative mean tissue viabilities compared to the mean of the negative control tissues.

The positive and negative control substance gave the expected results. The relative mean tissue viabilities of the test compound were > 100% for all exposure periods. Thus, in the described test Sodium N-lauroylsarcosinate (CAS 137-16-6) is considered to be non-corrosive.

The skin irritation properties of Sodium N-lauroylsarcosinate (CAS 137-16-6) were tested in an in vivo study according to OECD guideline 404 under GLP conditions (Frey-Tox GmbH, 2004a). In the study, 3 rabbits (Little russian) were exposed to a 30% (v/v) solution of the test substance in water. A sequential testing strategy was applied comprising an initial test in one animal and a confirmatory test with three animals. In the initial test, Sodium N-lauroylsarcosinate (CAS 137-16-6) was applied to the shaved skin of one animal for 3 min and 1 h using a semiocclusive dressing. In the confirmatory main test, the animals were similarly treated for an exposure period of 4 h. The treated skin was observed and evaluated at 1, 24, 48 and 72 h post-application.

In the initial test, the animal showed well defined erythema immediately after application. In the main test, well defined erythema was observed in 1/3 animals, and very slight erythema in 2/3 animals. At the 24, 48 and 72 h reading time point, moderate to severe erythema and very slight oedema were observed in one animal and very slight erythema in the remaining two animals with mean erythema scores of 3, 1 and 1 for animal 1/2/3 over 24, 48 and 72 h, respectively. All effects on skin were fully reversible within 14 days.

Thus, the test material was considered to be non-irritating at 30% (v/v) solution in water in this test system.

Furthermore, Sodium N-lauroylsarcosinate (CAS 137-16-6) was tested in a study according to a test method described in the U.S. Federal Hazardous Substances Act (U.S. Federal Register, 1973, Vol. 38, No. 187, Section 1500: 41) under GLP conditions (Toxicol Laboratories Limited, 1987b).

In the study, 6 female New Zealand white rabbits were exposed to a 10% (v/v) solution of the test substance in water applied onto both shaved (intact) and abraded skin for 24 h using an occlusive dressing. The treated skin was observed and evaluated at 24 and 72 h post-application. At the 24 h reading time point, well defined erythema was observed in all animals (intact and abraded skin) as well as defined oedema in 2 animals and slight oedema in 4 animals with intact skin. A decline of the irritant response was apparent at the 72 h reading; however well-defined erythema remained in 4 animals on intact and abraded skin, and very slight erythema remained in one animal on both intact and abraded skin. Very slight oedematous reaction was observed at three abraded sites and three intact sites and slight oedema on abraded skin in one animal was apparent. Thus, during the observation period of 72 h, the skin effects were not fully reversible. However, due to the short observation time and the observed decline of the irritant response, it cannot be excluded that the effects would have been reversible if a longer observation period would have been applied. Furthermore, only very slight to well defined erythema and very slight to slight oedema were observed, and no further local or systemic effects were reported. Thus, the test material at a 10% (v/v) solution in water was considered to be non-irritating based on an expert judgement.

In summary, Sodium N-lauroylsarcosinate (CAS 137-16-6) was considered to be non-corrosive in an in vitro skin corrosion test. Furthermore, Sodium N-lauroylsarcosinate (CAS 137-16-6) revealed under the experimental conditions as a 30% (v/v) solution no skin irritation properties in vivo. However, a 10% (v/v) solution of the test material showed non-reversible effects after 72 h of observation. Due to the short observation period in this study, and in combination with the declining tendency of the irritating effects, the result of the study was considered to be non-irritating at 10% (v/v).

Hence, Sodium N-lauroylsarcosinate (CAS 137-16-6) is considered to be non-irritating at ≤ 30%.

Classification as Skin irritation Category 2 for concentrations >30% and the neat substance is based on an expert judgement considering a worst case assumption.

Eye irritation

Two studies investigating the eye irritation properties of Sodium N-lauroylsarcosinate (CAS 137-16-6) are available. In the first study, Sodium N-Laurylsarcosinate was tested in vivo in a study according to OECD guideline 405 under GLP conditions (Frey-Tox GmbH, 2004b).

In 3 rabbits (Little russian) 0.1 mL of the test substance as 30% (v/v) solution in water was instilled into one eye in a single application without washing. The eyes were observed and reactions were evaluated 1, 24, 48 and 72 h and 7, 14 and 21 days after instillation.

Corneal opacity and iritis were seen at 24, 48 and 72 h in all three animals, resulting in individual mean cornea and iris scores of ≥ 1 and 1, respectively. Effects on cornea and iris were fully reversible within 21 days. All animals showed slight or well defined to moderate erythema of the conjunctivae at the 24, 48 and 72 h reading time points (mean erythema scores of animal 1/2/3 over 24, 48 and 72 h = 1/1.3/1) which were fully reversible within 14 days. Furthermore, all animals showed chemosis at the 24, 48 and 72 h reading time points (mean chemosis score animal 1/2/3 over 24, 48 and 72 h = 1.3/1.3/1.67) which were fully reversible within 7 days.

Thus, Sodium N-lauroylsarcosinate (CAS 137-16-6) was found to be an eye irritant at a concentration of 30%.

In addition, Sodium N-lauroylsarcosinate (CAS 137-16-6) was tested according to U.S. Federal Hazardous Substances Act (U.S) Federal Register, 1973, Vol. 38, No.187, Section 1500: 42 (Toxicol Laboratories Ltd, 1987c). In 6 New Zealand White rabbits, 0.1 mL of a 10% (v/v) solution in water was instilled into one eye. The eyes were observed, and reactions were evaluated 24, 48 and 72 h after instillation.

Iritis was apparent in the treated eye of 5/6 animals after 24 h and was not fully reversible within 72 h resulting in a mean iris score of 0.7 for all 6 animals over 24, 48 and 72 h. Corneal opacity was observed in 4/6 animals and was not fully reversible within 72 h. Conjunctival redness ranged from very slight to well defined erythema (mean conjunctivae score out of all 6 animals over 24, 48 and 72 h = 1.6) and conjunctivae swelling from slight to severe effects with 4/6 animals showing a mean conjunctival swelling ≥ 2 (mean conjunctivae score out of all 6 animals over 24, 48 and 72 h = 2.2) and was not fully reversible within 72 h in all animals.

Possibly due to the shorter observation period of 72 h effects were not reversible. However, regarding the calculated mean scores following grading at 24, 48 and 72 h, the test material is not considered to produce irreversible effects on the eye but rather irritating effects which would be reversible after a longer observation period.

In summary, both studies showed irritating effects to the eyes in concentrations of 10 and 30% (v/v) of the test substance. Sodium N-lauroylsarcosinate (CAS 137-16-6) is therefore considered to be irritating to the eye (Eye irrit 2) at concentrations of ≥ 1% and ≤ 30%.

Classification as Eye dam. 1 for concentrations > 30% and for the neat substance is based on an expert judgement considering a worst case assumption.

Justification for classification or non-classification

The available data on skin irritation of the substance Sodium N-lauroylsarcosinate (CAS 137-16-6) meet the criteria for classification for skin irritation category 2 (H315) according to Regulation (EC) No 1272/2008 at concentrations >30%.

The available data on eye irritation of Sodium N-lauroylsarcosinate (CAS 137-16-6) meet the criteria for classification for Eye dam. Category 1 (H318) at concentration > 30% and as Eye Irrit. 2 (H319) at concentrations ≥ 1% and ≤ 30% according to Regulation (EC) No 1272/2008.