Supernatant from the crystallisation of L-threonine from the broth filtrate from the fermentative production of L-threonine

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to OECD guideline 401 (1987) and Council Directive 92/32/EEC

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Commission Directive 92/32/EEC

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

L-Threonine mother liquor

IUPAC Name:

L-Threonine mother liquor

Details on test material:

-Name of test material (as cited in study report): L-Threonine containing mother liquor
Details are presented in "Confidential details on test material"

Test animals

Species:

rat

Strain:

other: Hsd/Win:WU

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
-Source: Harlan-Winkelmann GmbH, Germany
-Age at study initiation: 8 - 9 weeks
-Weight at study initiation: 144 - 163 g
-Fasting period before study: ca. 16 hrs before treatment
-Housing: Individually in Macrolon type II cages
-Certified diet ad libitum
-Tap water ad libitum
-Acclimation period: At least 5 days before dosing

ENVIRONMENTAL CONDITIONS
According to guideline

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED
-Dosing volume: 4.64 mL/kg bw (only one dose level tested)
-Concentration: 464 mg/mL

Doses:

2150 mg/kg bw

No. of animals per sex per dose:

5 m / 5 f

Control animals:

other: not required

Details on study design:

-Duration of observation period following administration: 14 days

-Frequency of observations:
Clinical signs: Continuously for the first 4 – 7 h, then once daily
Mortality: 1 – 2 times daily
Body weights: At beginning and on days 7 and 14 after dosing
Gross necropsy: all animals

No other examinations performed

Statistics:

not applicable

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 150 mg/kg bw

Mortality:

no

Clinical signs:

other: Sunken sides in 3/5 males and 5/5 females. Red incrustrated eyes and nose in 1/5 males. Symptoms were observed between 98 min and 8 days of observation.

Gross pathology:

No macroscopic findings were recorded at necropsy.

Applicant's summary and conclusion

Interpretation of results:

practically nontoxic

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

The acute oral toxicity of L-threonine mother liquor was tested in GLP study according to OECD guideline 401. In both male and female Hsd/Win:WU rats the oral LD50 is > 2150 mg/kg bw.