Sodium N-methyl-N-(1-oxo-9-octadecenyl)aminoacetate

Endpoint summary

Description of key information

Skin irritation in vitro (OECD 404): irritating
Eye irritation in vitro (non-guideline): inconclusive
Eye irritation in vivo (US-EPA § 163.81-4, “Primary eye irritation study”): corrosive, based on read-across

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 Oct - 17 Nov 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-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: LIttle 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
- 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 mg

Duration of treatment / exposure:

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

Observation period:

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

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: 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:

other: mean over 24, 48 and 72 h

Score:

2.33

Max. score:

4

Reversibility:

fully reversible within: 21 days

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: mean over 24, 48 and 72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible within: 21 days

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

other: mean over 24, 48 and 72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: scales were still apparent

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: mean over 24, 48 and 72 h

Score:

1.67

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: mean over 24, 48 and 72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: mean over 24, 48 and 72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

Immediately after application, the animal used in the preliminary test showed a well defined erythema. 1, 24, 48 and 72 h after application, well defined to moderate to severe erythema were observed in all animals (see Table 1 + 2 under “Any other information on results incl. tables”).
24, 48 and 72 h after application: slight to moderate oedema were observed in all animals. After 1 h slight oedema was observed in one animal.
7 days after application: isolated scales were observed on the anterior left test field of one animal and thick, brown scales on the middle left test field and a thick, brown crust of scales on the whole posterior left test field. The remaining two animals showed large, white scales on the whole anterior left test fields.
14 days after application: scales were observed in two animals whereas no skin reactions were observed for the third animal.
21 days after application: one animal still showed isolated scales.

Other effects:

No further local or systemic effects were observed.

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	2	1	1	0	0	0	0	0
1 h	0	0	3	2	2	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	2	1	2	0
24 h	3	1	3	3	3	2
48 h	2	2	3	2	3	2
72 h	2	2	3	2	3	2
Mean value 24 + 48 + 72 h	2.33	1.67	3.0	2.3	3.0	2.0

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: Skin irrit 2, H315
DSD: Xi, R38

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin corrosion

The skin irritation properties of Reaction products of oleoyl sarcosine with sodium hydroxide have been investigated in a study according to OECD guideline 404 under GLP conditions (Vaeth, 2005).

Three rabbits (Little Russian) were exposed to the unchanged test substance. A sequential testing strategy was applied comprising an initial test in one animal and a confirmatory test with all animals. In the initial test, the test substance 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 and 7, 14 and 21 days post-application.

In the initial test, the animal showed well defined erythema immediately after application. In the main test, well defined to moderate to severe erythema were observed in all animals resulting in mean erythema scores over 24, 48 and 72 h of 2.33, 3 and 3. Erythema were fully reversible within 21 days in 2/3 animals. 21 days after application one animal still showed isolated scales. In addition, slight to moderate oedema were observed in all animals resulting in mean oedema scores over 24, 48 and 72 h of 1.67, 2.3 and 2 being fully reversible within 7 days in all animals. No further local or systemic effects were observed.

In conclusion, the available data indicate that Reaction products of oleoyl sarcosine with sodium hydroxide is skin irritating.

Eye irritation

The eye irritation properties of Reaction products of oleoyl sarcosine with sodium hydroxide were assessed in an in vitro test using EPI ocular Tissue (OCL-200) (Vaeth, 2004).

Human derived corneal tissue models (OCL-200) were treated for 3, 30 and 60 min with the unchanged test material, and cell viability measurements were performed using the MTT assay. Negative and positive controls were included in the test and showed the expected results.

The %-viability of the test item compared to the negative control after 3, 30 and 60 min was 78, 77 and 79, respectively. Thus, only a slight decrease in tissue viability after treatment with the test item was apparent. The determined ET50 value was above 60 min for the test item at any time point, and thus only a minimal irritant potential of the test item was indicated according to the categorisation of Stern (Toxicology in vitro, 12 455-461 (1998)). Under the conditions of this in vitro study the test material is non/minimal irritant to reconstructed corneal epithelium.

However, this study does not provide adequate information on eye irritation properties for classification purposes. Thus, in order to fulfil the standard information requirements set out in Annex VIII, 8.2.1. and in accordance with Annex XI, 1.5., of Regulation (EC) No 1907/2006, read-across from the structurally related category member (Z)-N-methyl-N-(1-oxo-9-octadecenyl) glycine (CAS 110-25-8) was conducted.

The eye irritation properties of (Z)-N-methyl-N-(1-oxo-9-octadecenyl) glycine (CAS 110-25-8) were tested in a study performed according to US-EPA § 163.81-4, “Primary eye irritation study”, Federal Register, Vol 43, No. 163, August 22, 1978 (Kobel, 1981).

In a group of 3 male and 3 female New Zealand white rabbits 0.1 mL of the unchanged test substance was instilled into one eye of 3 animals in a single application without washing and with washing into one eye of the remaining 3 animals. The eyes were observed, and reactions were evaluated 24, 48 and 72 h and 4 and 7 days after instillation.

Rinsing of the eye following instillation was of low or no effect. No effects on iris were noted in any animal. Corneal opacity ≥ 1 was seen in the mean over 24, 48 and 72 h in 5/6 animals and was not fully reversible within 7 days. All animals showed diffuse beefy redness of the conjunctivae resulting in a mean conjunctivae score out of 3 for all 6 animals over 24, 48 and 72 h. Conjunctivae redness was not fully reversible within 7 days. After 7 days, in all animals obvious swelling with partial eversion of lids and discharge in various degrees were still apparent. No further local or systemic effects were reported.

Thus, classification as Eye dam. 1 was applied.

In summary, the in vitro study with showed non/minimal irritant effects to reconstructed human corneal epithelium. However, the structurally related category member (Z)-N-methyl-N-(1-oxo-9-octadecenyl) glycine (CAS 110-25-8) showed irreversible effects within an observation period of 7 days in vivo. Thus, classification as Eye Dam. 1 was applied, based on an expert judgement considering a worst case assumption.

Justification for selection of skin irritation / corrosion endpoint:
There is only one study available.

Justification for selection of eye irritation endpoint:
Hazard assessment is conducted by means of read-across based on a category approach/read-across from a structural analogue and weight of evidence from these studies. The available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties among category members and overall quality assessment (refer to the endpoint discussion for further details).

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

The available data on skin irritation of Reaction products of oleoyl sarcosine with sodium hydroxide meet the criteria for classification for Skin irritation category 2 (H315) according to Regulation (EC) No 1272/2008 and as skin irritating (Xi; R38) according to Directive 67/548/EEC.

 

The available data on eye irritation of a substance structurally related to Reaction products of oleoyl sarcosine with sodium hydroxide

according to Regulation (EC) No 1907/2006, Annex XI, 1.5. meet the criteria for classification for Eye dam. category 1 (H318) according to Regulation (EC) No 1272/2008 and as Risk of serious damage to eyes (Xi; R41) according to Directive 67/548/EEC.