Methyl (S)-(-)-lactate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1994-06-16 to 2000-02-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted 24th February 1987

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

propyl (2S)-2-hydroxypropanoate

EC Number:

611-025-7

Cas Number:

53651-69-7

Molecular formula:

C6H12O3

IUPAC Name:

propyl (2S)-2-hydroxypropanoate

Specific details on test material used for the study:

- Name of test material (as cited in study report): n-propyl lactate
- Analytical purity: 99.5%
- Lot/batch No.: 3
- Appearance: clear, colourless liquid
- Storage conditions: ambient

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
Test material was used undiluted.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga, Sulzfeld, Germany
- Age at study initiation: 6-7 weeks
- Housing: 5 animals/cage (stainless steel cages, fitted with wire-screen floor and front); during treatment animals were housed individually
- Diet: standard laboratory diet, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 65 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 52.5 - 92.5
- Air changes (per hr): ca. 10
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: at least 20 cm²
- % coverage: at least 10% of the total body surface
- Type of wrap if used: plastic foil

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes, with lukewarm water
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2 mL/kg bw

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: observations were made within 1 hour and within 4 hours after the start of dosing, and subsequently at least once daily throughout an observation period of 14 days
- Frequency of weighing: on day 0, day 3, 7 and 14
- Necropsy of survivors performed: yes, at the end of the observation period (day 14) all animals were killed with carbon dioxide and examined for external changes. Next, the abdomen and thorax of each animal was opened and examined for gross pathological changes.
- Skin reactions were scored according to Draize et al., 1944 (see Table 1 in box "Any other information on materials and methods incl. tables") and were made on day 1, 3, 7 and 14 after patch removal

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occured during the 14-day observation period.

Clinical signs:

other: Encrustation of the nose, on day 1 or at 72 h or day 3 recorded in some of the animals. In the skin site treated with the test substance, only slight encrustation was observed in 2 males and 1 female on day 1 of the study. No other clinical symptoms obser

Body weight:

other body weight observations

Remarks:

no adverse effects on bodyweight gain were noted

Gross pathology:

No treatment-associated changes were detected in the animals.

Applicant's summary and conclusion

Interpretation of results:

other: CLP criteria not met

Conclusions:

Propyl (S)-lactate is not dermally toxic and the LD50 is >2000 mg/kg bw.

Executive summary:

In an acute dermal toxicity study conducted according to OECD TG 402 groups of young adult Wistar rats (5/sex) were dermally exposed to n-propyl-lactate (purity 99.5%) for 24 hours to at least 10% of the total body surface area at a dose of 2000 mg/kg bw. Animals were observed for 14 days. No mortality was observed among the animals. The only clinical symptom detected was encrustation of the nose on days 1 or 3 of the study. All animals gained weight day during the 14-day observation period, except for a slight dip in the body weight of all males and 4 females, recorded on day 3. No treatment-associated changes were detected in the animals during the gross pathology examination.

Based on the results, the dermal LD50 of the substance for both male and female rats can be considered to be greater than 2000 mg/kg bw.