Registration Dossier

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Description of key information

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records
Reference
Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes
Species:
rabbit
Strain:
other: White russian (Albino)
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: males 9, 10 months; female 10 months
- Weight at study initiation: males 2.59, 2.67 kg, female 2.69 kg
- Housing: individually
- Diet: approx. 120 g/day x animal, standard diet sniff K, special diet for rabbits
- Water: ad libitum
- Acclimation period: 1 day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.0-20.5°C
- Humidity (%): 53-68%
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 20.07.1993 To: 30.07.1993
Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
water
Controls:
other: control site at the same animal
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: 0.5 g

VEHICLE
- Amount(s) applied: 0.21 ml
Duration of treatment / exposure:
4 hours
Observation period:
1, 24, 48 and 72 hours after removal of the patches
Number of animals:
3
Details on study design:
TEST SITE
- Area of exposure: 6.25 cm2
- Type of wrap if used: cellulose fabric coated with natural rubber, synthetic film glue

REMOVAL OF TEST SUBSTANCE
- Washing: remaining test material was gently washed off as far as possible
- Time after start of exposure: 4 hours
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
other: 24, 48 and 72 hours
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 72 hours
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Irritation parameter:
edema score
Basis:
animal #1
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Irritation parameter:
edema score
Basis:
animal #2
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
0
Irritation parameter:
edema score
Basis:
animal #3
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
0
Irritant / corrosive response data:
An edema was not observed in all three animals during the observation period.
Other effects:
Systemic toxic effects did not occur after dermal application of the test substance. The general condition of the test animals was not affected.

The single application (4 hours, occlusive patch) of 0.5 g L-threonine feed grade to the intact skin of each of three rabbits caused very slight changes in two animals.

Interpretation of results:
study cannot be used for classification
Remarks:
Migrated information
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
GLP compliance:
yes
Species:
rabbit
Strain:
other: White russian (Albino)
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Age at study initiation: 11-12 months
- Weight at study initiation: 2.60-3.40 kg
- Housing: individually
- Diet: 120 g/day x animal, standard diet sniff K, special diet for rabbits
- Water: ad libitum
- Acclimation period: 1 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.0-20.5°C
- Humidity (%): 53-73%
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 26.07.1993 To: 05.08.1993
Vehicle:
unchanged (no vehicle)
Controls:
other: untreated eye of the same animal served as control
Amount / concentration applied:
TEST MATERIAL
- Amount applied: 59.1-61.1 mg
- Concentration: undiluted
Duration of treatment / exposure:
Single exposure, no washing
Observation period (in vivo):
1, 24, 48 and 72 hours after application
Number of animals or in vitro replicates:
3
Details on study design:
REMOVAL OF TEST SUBSTANCE: The treated eye was not rinsed.
TOOL USED TO ASSESS SCORE: Cliptrix pencil light (Varta, Hannover, No. 645)
Irritation parameter:
cornea opacity score
Basis:
animal: 1-3
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Irritation parameter:
iris score
Basis:
animal: 1-3
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
2
Irritation parameter:
conjunctivae score
Basis:
animal: 1-3
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
3
Irritation parameter:
chemosis score
Basis:
animal: 1-3
Time point:
other: 24, 48 and 72 hours
Score:
0
Max. score:
4
Irritant / corrosive response data:
The irritation index is 0.
Other effects:
There were no systemic toxic effects after conjunctival application of the test substance. The general condition of the animals was undisturbed.

In the cornea and iris of all three animals no alterations were detected during the observation period.

The conjunctiva of one animal reacted with hyperemia (grade 1) only at the application day. In the two other animals no changes were observed.

Interpretation of results:
study cannot be used for classification
Remarks:
Migrated information
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Skin irritation

The acute dermal irritation of L-threonine was investigated with rabbits in a GLP study according to OECD guideline 404 (93 -0021 -DGT). There was no indication of a systemic effect of treatment. The single application (4 hours, occlusive patch) of 0.5 g L-threonine to the intact skin of each of three rabbits caused very slight changes in two animals. Therefore, L-threonine can be classified as not skin irritating. This result is supported by a further GLP study according to OECD guideline 404 (2002 -0792 -FGT).

Eye irritation

The acute eye irritation of L-threonine was investigated with rabbits in a GLP study according to OECD guideline 405. There was no indication of a systemic effect of treatment. In the cornea and iris of all three animals no alterations were detected during the observation period. The conjunctiva of one animal reacted with hyperemia (grade 1) only at the application day. In the two other animals no changes were observed. Therefore, L-threonine can be classified as not eye irritating. This result is supported by a further GLP study according to OECD guideline 405 (2002 -0794 -FGT).

Justification for classification or non-classification