Sodium (S)-lactate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

The study was conducted according to the AFNOR (Association Française de Normalisation) guidelines (as valid in 1982, the year in which this study was published). Although the used protocol is similar to the current OECD protocol OECD TG 405, it differed in some respects. For instance, the scoring of the eye irritation test was done on a different (but related) scale than the current OECD TG 405 protocol and the applied scoring included a wider range of categories of severity of eye irritation (6 instead of 3 as nowadays applied in OECD TG 405; EC1272/2008). In addition, in this published study, no individual scores for the animals are given, but values based on averages of all animals.

Data source

Reference

Reference Type:

publication

Title:

Evaluation of the ocular-irritation potential of 56 compounds

Author:

Guillot J.P. et al.

Year:

1982

Bibliographic source:

Food Chem. Toxic. 20, 573-582

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

Version of 1979 (deviates from current)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: AFNOR

Version / remarks:

Association Français de Normalisation (1982)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Official method approved by the French authorities for the testing of cosmetics and toiletries (Journal Officiel de la République Français, 1971 & 1973)

Deviations:

no

Principles of method if other than guideline:

Application of 0.1 mL of a 60 % aqueous solution of Sodium lactate into the lower conjunctival sac of one eye per rabbit (the other eye serving as control) to in total 6 New Zealand male albino rabbits and (with no rinsing of the eyes) subsequent observation of the eyes at 1, 24, 48, 72, 96 and 168 hours post substance application. Scoring was done on the AFNOR scale for interpretation of ocular irritation evaluations. The scores represent a total summed score (maximum 110) of the conjunctiva (maximum 20) + iris (maximum 10) + cornea (maximum 80) scores. In addition, reversibility is taking into account in this scoring method (completeness of recovery at 96 hours).

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Sodium lactate

EC Number:

200-772-0

EC Name:

Sodium lactate

Cas Number:

72-17-3

Molecular formula:

C3H5NaO3

IUPAC Name:

sodium 2-hydroxypropanoate

Specific details on test material used for the study:

- Physical state: colourless liquid

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: substance was applied undiluted

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Roucher SA, Couhé
- Age at study initiation: Not specified
- Weight at study initiation: 2.5 kg
- Housing: Not specified
- Diet (e.g. ad libitum): Not specified
- Water (e.g. ad libitum): not specified
- Acclimation period: Not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Not specified
- Humidity (%): Not specified
- Air changes (per hr): Not specified
- Photoperiod (hrs dark/rs light): Not specified

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 mL of a 60 % aqueous solution

Duration of treatment / exposure:

single treatment

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

6

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no

SCORING SYSTEM: A scoring system based on the AFNOR recommendations was used with modifications where appropriate. At each observation time, lesions of the conjunctiva, iris and cornea were scored separately using a numerical system based on that of Kay & Calandra (1962), the sum of these scores being the individual irritation index (IOI) for each animal. Calculation of the mean (and the standard deviation) of the IOI values obtained at any one time gave the mean ocular irritation index (MOI). The greatest MOI obtained over the range of observation times was identified as the acute ocular irritation index (AOI). See Table 1 in box “Any other information on materials & methods incl. tables”.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Remarks on result:

probability of weak irritation

Results 2

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Results 3

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Results 4

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Results 5

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Irritant / corrosive response data:

The observed maximum acute (at 1 or 24 hours) irritation index for sodium lactate was 12 (out of a maximum of 110) . This score would imply a classification "slightly irritant" when using the 1982 AFNOR criteria and categories., ie sodium lactate would end up in category 2 of 6 ranging from non irritant (Cat. 1) to extremely irritant (Cat. 6). After 48 hours, the mean irritation index (i.e. mean of 1, 24 and 48 hours) was 2.5, implying extensive recovery after 48 hours. Taking into account the more elaborate categorization (next to non irritant substances and additional 5 categories of eye irritant substances in the 1982 AFNOR versus only 2 categories on eye irritation severity according to CLP Regulation 1272/2008) and the rapid reversibility of the observed eye effects of Sodium lactate, the substance would not be classified as eye irritant applying CLP classifcation criteria.

Other effects:

None of the animals died or showed clinical signs during the course of testing.

Any other information on results incl. tables

Table 2: Ocular irritation indices determined in the rabbit in accordance with the principles of the proposed AFNOR protocol

Test material	Appearance	Approx. pH	Rinsing procedure	AOI	MOI	IOI	Classification AFNOR
Sodium lactate (purified, 60 % aqueous solution)	Colourless liquid	8.0	None	12.00	2.5 [2]	-	SII

AOI: Acute ocular irritation index, which was the 1-hr MOI in the case of the irritant and very irritant substances and was the 24-hr MOI for the severely and extremely irritant substances

MOI: Mean ocular irritation index after the number of days indicated in square brackets.

IOI: Individual ocular irritation index on day 7 in the number of rabbits indicated in brackets.

SI: Slightly irritant

Applicant's summary and conclusion

Interpretation of results:

other: CLP criteria not met

Conclusions:

In a primary eye irritation study conducted according to AFNOR, Sodium lactate can be considered as not irritating to the eye by appling CLP criteria.

Executive summary:

In an eye irritation study conducted according to AFNOR, 0.1 mL of the test item was instilled into the conjunctival sac of one eye of each of six New Zealand White rabbits. Animals were observed for 7 days. At each observation time, lesions of the conjunctive, iris and cornea were scored separately using a numerical system based on that of Kay & Calandra (1962), the sum of these scores being the individual ocular irritation index (IOI) for each animal. Based on the results, the test item can be considered as not irritating to the eye by applying CLP criteria.