Aspartic acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Aspartic acid

EC Number:

200-291-6

EC Name:

Aspartic acid

Cas Number:

56-84-8

Molecular formula:

C4H7NO4

IUPAC Name:

aspartic acid

Details on test material:

Identity: L-Aspartic acid
Chemical name: L-Aspartic acid
Batch number: ASP 261/1
Expiry: Stable for duration of the study (2 years)
Purity: 99.0% to 101.0%
Appearance: White crystals
Storage conditions: 4°C in the dark
Date received: 16 November 1993

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Three healthy adult rabbits of tbe New Zealand White strain were obtained from Froxfield (U .K.)
Ltd., Petersfield, Hampshire, England.
They were in the weight range of 2.6 to 2.8 kg and approximately 11 to 12 weeks of age, prior to
treatment (Day 1). All rabbits were acclimatised to tbe experimental environment.
The rabbits were selected witbout conscious bias for the study. They were housed individually in
metal cages with perforated floors in Building R 14 Room 5.
A standard laboratory diet SDS Stanrab (P) Rabbit Diet and drinking water were provided ad libitum.
The batch of diet used for tbe study was not analysed for nutrients, contaminants or micro-organisms.
Results of routine chemical examination of drinking water at source as conducted usually weekly by
tbe supplier, are made available to Huntingdon Research Centre Ltd. as quarterly summaries.
Animal room temperature was maintained at approximately 19 DC and relative humidity at 30 - 70 %.
These environmental parameters were recorded daily. Air exchange was maintained at approximately
19 air changes per hour and lighting was controlled by means of a time switch to give 12 hours of
artificial light (0700 - 1900 hours) in each 24 hours period.
Each animal was identified by a numbered aluminium tag placed through tbe edge of one ear. This
number was unique witbin tbe HRC Industrial Toxicology Department tbroughout tbe duration of the
study. Each cage was identified by a coloured label displaying the study schedule number, animal
number and initials of tbe Study Director and Home Office licensee.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Amount / concentration applied:

Approximately 24 hours prior to application of the test substance, hair was removed with electric
clippers from the dorso-Iumbar region of each rabbit exposing an area of skin approximately
100 mm x 100 mm.

Duration of treatment / exposure:

A 0.5 g amount of the test substance was applied under a 25 mm x 25 mm gauze pad which had
been moistened with 0.5 ml distilled water to one intact skin site on each animal.
Each treatment site was covered with "Elastoplast" elastic adhesive dressing for four hours. The
animals were not restrained during the exposure period and were returned to their cages immediately
after treatment.
At the end of the exposure period, the semi-occlusive dressing and gauze pad were removed and the
treatment site was washed with warm water (30° to 40°C) to remove any residual test substance. The
treated area was blotted dry with absorbent paper.

Observation period:

Clinical signs
All animals were observed daily for signs of ill health or toxicity.
Dermal responses
Examination of the treated skin was made on Day I (i.e. approximately 60 minutes after removal
of the dressings) and on Days 2, 3 and 4 (equivalent to 24, 48 and 72 hours after exposure).

Number of animals:

3

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24h;48h;72h;96h

Score:

0

Max. score:

0

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24h;48h;72h;96h

Score:

0

Max. score:

0

Irritant / corrosive response data:

CLINICAL SIGNS
There were no signs of toxicity or ill health in any rabbit during the observation period.
DERMAL RESPONSES
The numerical values given to the dermal reactions elicited by L-Aspartic acid are shown in Table 1.
No dermal response to treatment was observed in any animal throughout the observation period.

Any other information on results incl. tables

CLINICAL SIGNS There were no signs of toxicity or ill health in any rabbit during the observation period. DERMAL RESPONSES The numerical values given to the dermal reactions elicited by L-Aspartic acid are shown in Table 1. No dermal response to treatment was observed in any animal throughout the observation period.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information

Executive summary:

A study was performed to assess the skin irritation potential of L-Aspartic acid to the rabbit. The method followed was that described in EEC. Methods for the determination of toxicity, Annex to Directive 92/69/EEC (OJ No. L383A, 29.12.92), Part B, Method B.4. Acute toxicity (skin irritation). Three rabbits were each administered a single dermal dose of 0.5 g of the test substance and observed for four days. . No reactions were observed following a single semi-occlusive application of L-Aspartic acid to intact rabbit skin for four hours. L-Aspartic acid does not require labelling with the risk phrase R38 "Irritating to skin" in accordance with EEC Council Directive 79/831/EEC, Annex VI, Part lI(D) as described in Commission Directive 931211EEC.