Registration Dossier

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 guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
other: Commission Directive 92/32/EEC
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 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:
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.
Body weight:
No adverse effects.
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.