Methyl (S)-(-)-lactate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1995-06-19 to 1995-07-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

adopted 17th July 1992

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl (S)-2-hydroxypropionate

EC Number:

211-694-1

EC Name:

Ethyl (S)-2-hydroxypropionate

Cas Number:

687-47-8

Molecular formula:

C5H10O3

IUPAC Name:

ethyl 2-hydroxypropanoate

Specific details on test material used for the study:

- Name of test material used in the report: ethyllactate
- CAS No.: 687-47-8
- Trade name: Purasolv EL
- Batch No.: 950122
- Appearance: clear, colourless liquid
- Purity: 98%
- Storage: ambient

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPF bred New Zealand White albino rabbits were obtained from the Broekmans Institue, Someren, the Netherlands
- Age at study initiation: males, young adult
- Weight at study initiation: 2130-2220 g
- Housing: individually in stainless steel cages, fitted with perforated floor
- Diet (e.g. ad libitum): standard laboratory rabbit diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 6/7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 52.5-75
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 / 12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

An amount of 0.5 mL of the test substance was distributed over a patch measuring 2.5 x 2.5 cm.

Duration of treatment / exposure:

4 hours

Observation period:

14 days

Number of animals:

3

Details on study design:

Three or four days prior to the start of the study, the hair was removed from the back and flanks of the animals using electric clippers in a way as to avoid abrasions. One day prior to application of the test material, the skin site was inspected for hair growth and the clipping was repeated. Just prior to application, a skin site suitable for application was selected on the clipped back and flanks of the animal. An amount of 0.5 mL of the test substance was distributed over a patch measuring 2.5 x 2.5 cm. The patch loaded with the test substance was fixed tot the selected application site by means of adhesive tape. Subsequently, the entire trunk of the rabbit was wrapped with self-adhesive-gauze to maintain the patch in position and to retard evaporation of volatile substances. The gauze was additionally fastened with two stripes of tape. After a 4-hour exposure period, the test substance and patch were removed, and the test site was cleaned with a moistened tissue. Circa 1 hour later, the resulting skin reactions were evaluated by the method of Draize et al. (J. Pharmacol. Exp. Ther. 82 (1944) 377-390). Further skin readings were made at approximately 24, 48 and 72 hours, and at 7 and 14 days after treatment.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

See Table 1 in box "Any other information on results incl. tables".

Other effects:

At 7 days after treatment, slight scaliness was observed in the two rabbits that showed skin irritation during the first days on the edges of the application area (<1 mm) only. At 14 days after treatment, the scaliness had cleared.

Any other information on results incl. tables

Table 1 - Skin irritation scores of ethyl lactate, after a single 4-hour dermal exposure

Animal no.	Hours or days after removal of the test material:
	1 hr	24 hr	48 hr	72 hr	7 d
	A-B	A-B	A-B	A-B	A-B
12	0-0 (1-1)	0-0 (2-2)	0-0 (2-2)	0-0 (2-1)	0-0
8	0-0 (1-1)	0-0 (2-2)	0-0 (2-2)	0-0 (2-1)	0-0
14	0-0 (1-1)	0-0 (1-1)	0-0	0-0
Erythema (A):	0.0	0.0	0.0	0.0	0.0
Oedema (B):	0.0	0.0	0.0	0.0	0.0

 

() Skin effects were located on a very small skin area on the edge of the application area (width less than 1 mm), most probably caused by pressure of the bandage on the test patch underneath. Therefore, the toxicological significance of these skin effects is considered dubious.

Applicant's summary and conclusion

Interpretation of results:

other: CLP criteria not met

Conclusions:

Under the given conditions, the test item is not irritating to the skin of rabbits.

Executive summary:

In a primary dermal irritation study (according to OECD Guideline 404), young adult male SPF bred New Zealand White albino rabbits (n= 3; weight 2130 - 2220 g) were dermally exposed to 0.5 mL of ethyl (S)-lactate (purity: 98%) to an area of 2.5 x 2.5 cm under occlusive conditions for 4 hours. Animals were then observed for 14 days and irritation was scored by the method of Draize et al. Only mild skin effects were observed on a very small skin area on the edge of the application area, most probably by pressure of the bandage on the test patch underneath. Since normally these kind of exposure conditions will not occur in humans, the toxicological significance of these skin effects was considered dubious. Furthermore, the mean erythema and oedema scores were 0. Based on these results, Ethyl (S)-lactate can be considered as non-irritant to the skin of rabbits. Therefore, classification for skin irritation according to CLP Regulation 1272/2008 is not warranted.