L-threonine, fermentation products byproduct

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to OECD guideline 402 (adopted 1987)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Remarks:

(Harlan Laboratories Ltd)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(2S)-2-amino-3-hydroxybutanoic acid

EC Number:

923-725-2

Molecular formula:

Not applicable (UVCB substance)

IUPAC Name:

(2S)-2-amino-3-hydroxybutanoic acid

Details on test material:

- Name of test material (as cited in study report): Biofert Plusz
Details are presented in "Confidential details on test material"

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories Ltd.
- Age at study initiation: 9 (males) or 11 weeks (females)
- Weight at study initiation: 245-258 g (males) and 190-205 g (females)
- Housing: individually
- certified diet ad libitum
- tap water ad libitum
- Acclimation period: Under laboratory conditions, after health examination. Only animals without any visible signs of illness were used for the study.

ENVIRONMENTAL CONDITIONS
according to guideline

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 10% of the total body surface (one day before treatment, the backs of the animals were clipped with an electric clipper; re-shaved on test days 6, 9 and 13)
- % coverage: semi-occlusive dressing was wrapped around the abdomen and fixed with an elastic adhesive bandage


REMOVAL OF TEST SUBSTANCE
- Time after start of exposure: 24 h
- Washing: dressing was removed and the skin was washed up with lukewarm tap water and dried with disposable paper toweis

TEST MATERIAL
undiluted test substance

Duration of exposure:

24 h

Doses:

7.12 mL of the liquid Biofert Plusz corresponding to 2000 mg/kg bw dry mass

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations (clinical signs including local effects): Daily during the acclimatization period, during the first 30 minutes and at approximately 1, 2, 3 and 5 hours after administration on test day 1. Once daily during days 2-15. All abnormalities were reeorded.
- Frequency of weighing: On test days 1 (prior to administration), 8 and 15.
- Necropsy: yes, at termination (day 15)
- Other examinations performed: no

Statistics:

not used

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

other: dry mass

Remarks on result:

other: dose corresponds to 7.12 mL/kg bw of the liquid test substance; no clinical signs, no relevant effects on body weight, no findings at necropsy

Mortality:

no mortality

Clinical signs:

other: No clinical signs observed during the course of the study.

Gross pathology:

No macroscopic findings were observed at necropsy.

Other findings:

no

Applicant's summary and conclusion

Interpretation of results:

practically nontoxic

Remarks:

Migrated information

Conclusions:

In male and female Wistar rats the dermal LD50 is > 2000 mg/kg bw (related to dry mass).