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

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

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 404 (1981)

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 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Commission Directive 92/32/EEC

GLP compliance:

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:

rabbit

Strain:

other: White russian (Albino)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
-Source: ASTA Medica AG, Halle, Germany
-Age at study initiation: 10 months
-Weight at study initiation: 2430 – 2800 g
-Housing: individually
-Certified diet ad libitum
-Tap water ad libitum
-Acclimation period: At least one day under test conditions before application of the test substance

ENVIRONMENTAL CONDITIONS
According to guideline

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: Opposite area of the dorsal skin was treated in the same way but without test substance

Amount / concentration applied:

TEST MATERIAL
-Amount(s) applied: 0.5 mL liquid test item
-Concentration: undiluted liquid test substance

Duration of treatment / exposure:

4 h

Observation period:

1, 24, 48, and 72 h after patch removal

Number of animals:

2 females and 1 male

Details on study design:

One day before treatment the dorsal skin area was clipped. 0.5 mL of the test substance was given on the left of the vertebral column, covered with a patch (6.25 cm2) and bandaged for complete occlusion. After 4 h exposure the dressing was removed and the remaining test substance was washed off.
Scoring system according to Guideline.
The examination included also the occurrence of clinical symptoms (systemic toxicity).
Duration of observation period: 3 days.

Results and discussion

In vivo

Results

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 1 - 72 h

Score:

0

Max. score:

4

Remarks on result:

other: No erythema, eschar and edema in any animal at any time point.

Irritant / corrosive response data:

Neither erythema nor edema was seen in any rabbit.

Other effects:

No clinical signs of systemic toxicity were observed in the animals during the study.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

L-Threonine mother liquor was tested for skin irritation in a GLP study according to OECD guideline 404. Neither erythema nor edema was seen in any rabbit (PDII = 0) and there were also no clinical signs of systemic toxicity.