Aspartic acid

Endpoint summary

Description of key information

L-aspartic acid is not classified as irritant or corrosive.

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

Study period:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study with GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Supplier: Charles River Wiga, D-97633 Sulzfeld.Hygiene: Optimal hygienic conditions.
Weight: 1.8 to 2.0 kg at the start of the study.
Room temperature: Average of 19.1 °C (continuous control and recording).
Relative humidity: Average of 53.6 % (continuous control and recording).
Air exchange: 12 per hour.
Light: Artificial light from 6 a.m. to 6 p.m.
Cages: Individual caging in metal wire cages, 79 cm x 59 cm bottom area, 38 cm height, with a wooden rest shelf, 15 cm x 59 cm.
Feed Altromin 2023 diet for rabbits, ad libitum. Hay-briquetteswere offered additionally as a dietary supplement.
Water: Tap water from an automatic watering system, ad libitum.
Acclimatisation: 5 days.

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Remarks:

substance was moistened with 1 mL.

Controls:

not required

Amount / concentration applied:

0.5 g

Duration of treatment / exposure:

4 h

Observation period:

The skins of the animals were examined for local alterations after the clipping procedure (one day before the application) and immediately before the application. The treated areas and the surrounding untreated skin (control area) of the animals were examined for erythema/eschar and oedema as well as for other local alterations approximately 1, 24, 48 and 72 hours after patch removal.

Number of animals:

3 females.

Irritation parameter:

other: erythema as well as edema scores

Basis:

animal: No. 1, 2 and 3

Time point:

other: 1, 24, 48 and 72 hours after patch removal.

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Irritant / corrosive response data:

All areas to be treated with the test substance and all control areas were normal before the application and at each observation time.

Other effects:

No general toxic effects were noted.

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

All exposed skin sites were normal at each examination term.

Executive summary:

The possible irritating or corrosive effects of the substance, following a single application to the intact skin of rabbits, was investigated in conformance with the OECD-Guideline 404 and the Directive 92/69/EEC, method B.4.

All exposed skin sites were normal at each examination term.

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

Study period:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study with GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Supplier: Charles River Wiga, D-97633 Sulzfeld.
Weight: 2.1 to 2.4 kg at the start of the study.
Hygiene: Optimal hygienic conditions.
Room temperature: Average of 19.3 °C (continuous control and recording).
Relative humidity: Average of 52.6 % (continuous control and recording).
Air exchange: 12 per hour.
Light: Artificial light from 6 a.m. to 6 p.m.
Cages: Individual caging in metal wire cages, 79 cm x 59 cm bottom area, 38 cm height, with a wooden rest shelf, 15 cm x 59 cm.
Feed: Altromin 2023 diet for rabbits, ad libitum. Hay-briquetteswere offered additionally as a dietary supplement.
Water: Tap water from an automatic watering system, ad libitum.
Acclimatisation: 5 days.

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

The approximate equivalent of 0.1 mL of the test substance was administered per animal into the conjunctival sacs of the right eyes by gently pulling the lower lids away from the eyeballs for instillation. The eyes were held closed for about one second to prevent a loss of test substance.
The weighed amounts of the individual doses were 85, 80 and 80 mg.

Duration of treatment / exposure:

Single application. The test substance was administered into the conjunctival sacs of the right eyes by gently pulling the lower lids away from the eyeballs for instillation. The eyes were held closed for about one second to prevent a loss of test substance.

Observation period (in vivo):

72 h for 2 animals; 6 d for 1animal.

Number of animals or in vitro replicates:

3 females.

Details on study design:

The left eyes remained untreated and served as a control.
Firstly, the test substance was given to one animal. As no evidence for a serious damage to the eye of this animal was found until 72 h p.a. (no corrosive effect), the test substance was administered to the other two animals too.

Irritation parameter:

cornea opacity score

Basis:

animal: #1 and #3

Time point:

other: 1 to 72 h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

other: mean of 24 to 72 h

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 48 h

Remarks on result:

other: for details see below.

Irritation parameter:

iris score

Basis:

animal: #1, #2 and #3

Time point:

other: 1 - 72 h p.a.

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

other: mean (24-72 h)

Score:

0.7

Max. score:

1

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: For details see below.

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

other: Mean (24-72 h)

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 6 d

Remarks on result:

other: For details see below.

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

other: Mean (24-72 h)

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 48 h

Remarks on result:

other: For details see below.

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: Mean (24-72 h)

Score:

0

Max. score:

2

Reversibility:

fully reversible within: 24 h

Remarks on result:

other: For details see below.

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

other: Mean (24-72 h)

Score:

1.3

Max. score:

3

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: For details see below.

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

other: Mean (24-72 h)

Score:

0

Max. score:

3

Reversibility:

fully reversible within: 24 h

Remarks on result:

other: For details see below.

Irritant / corrosive response data:

The untreated eyes ("control eyes") were normal at each observation time.
The eyes, treated with the test substance ("test eyes") were normal before the instillation.
After the instillation of the test substance, the following findings were made:
Cornea: A score of "1" from 1 h to 24 h p.a. in 1/3 animals. The affected area was one quarter to one half of the cornea. 25 % of the cornea were homogeneously stained after an additional examination by instillation of fluorescein 24 h p.a. This indicates a damage of the anterior corneal epithelium. 48 h p.a. the cornea was normal again.
The corneae of the other two animals were unaffected.
Iris: Not affected.
Conjunctivae, redness: A score of "1" from 1 h p.a. until a maximum of 72 h p.a. in all animals.
Conjunctivae, chemosis: Initial scores of "2" or "3" from 1 h p.a., degrading afterwards, until a maximum of 48 h p.a. in all animals.
Additional findings: Discharge with moistening of the lids and hairs just adjacent to the lids 1 h p.a. in 2/3 animals.

Other effects:

No other than ocular alterations were noted.

Interpretation of results:

slightly irritating

Remarks:

Migrated information Criteria used for interpretation of results: not specified

Conclusions:

According to the results obtained and the criteria of CLP and of 67/548/EC, the substance is not classified as irritant.

Executive summary:

The possible irritating or corrosive effects of the substance, following a single administration into a conjunctival sac of rabbits, was investigated in conformance with the OECD-Guideline 405 and the Directive 92/69/EEC, method B.5.

Some alterations were noted but according to the criteria of CLP and of 67/548/EC, the substance is not classified as irritant.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for selection of skin irritation / corrosion endpoint:
A key study according to present guidelines and with GLP.

Justification for selection of eye irritation endpoint:
A key study according to present guidelines and with GLP.

Effects on eye irritation: slightly irritating

Justification for classification or non-classification

No effects were observed in the skin irritation study.

Some minor alterations were observed in the eye irritation study, but not severe enough to cause a classification of the substance.