diethyl 1,4-cyclohexanedicarboxylate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 29 November to 7 December 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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)

Version / remarks:

Adopted 31st July 1992

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

417-310-0

EC Name:

-

Cas Number:

72903-27-6

Molecular formula:

C12H20O4

IUPAC Name:

1,4-diethyl cyclohexane-1,4-dicarboxylate

Test material form:

liquid

Details on test material:

Test material identification: ST 02 C 94
Description: colourless liquid
Date received; 25th November 1994

Specific details on test material used for the study:

Storage conditions: refrigerator in the dark

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Froxfield Farms (UK) Limited, Froxfield, Hampshire - U.K.
- Housing: The animals were individually housed in grid bottomed metal cages.
- Diet (e.g. ad libitum): ad libitum (antibiotic free rabbit diet (SQC standard rabbit pellets produced by Special Diet Services, Witham, Essex)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-21
- Humidity (%): 47-62
- Air changes (per hr): air conditionned room
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL

Duration of treatment / exposure:

4 hours

Observation period:

7 days

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 2.5 cm²
- Type of wrap if used: 0.5mL aliquot of the test article was placed evenly over a 2.5 cm square of surgical lint which was then applied to the skin site, on the flank and caudal to the last rib, so that the test article was in contact with the skin. This test patch was held in position by encircling the trunk of the animal with a length of 'Elastoplast' elastic adhesive bandage 7.5 cm wide.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): gently with cotton wool soaked in warm water
- Time after start of exposure: 4 hours

SCORING SYSTEM:

Erythema and eschar formation:
0 No erythema
1 Very slight erythema (barely perceptible)
2 Well definederythema
3 Moderate to severe erythema
4 Severe erythema (beet redness) to slight eschar formation (injuries in depth)

Oedema formation:
0 No oedema
1 Very slight oedema (barelyperceptible)
2 Slight oedema(edges of area well defined by definite raising)
3 Moderate oedema (raised approximately Imm)
4 Severe oedema (raised more than 1mm and extending beyond area of exposure)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 h

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

See "Illustration" for detailed results

Other effects:

none

Any other information on results incl. tables

Evaluation of Results

If significant inflammation but no full thickness destruction of skin tissue is caused and persists for 24 hours after the end of the exposure period, the test article would be classified as irritant and would attract the risk phrase "R38 Irritating to skin".

According to the criteria described in Commission Directive 93/21/EEC, inflammation is deemed to be significant when the test is completed in 3 rabbits if an individual mean score (calculated from the values recorded at the 24, 48 and 72 hour examinations) for either erythema or oedema of 2 or more is obtained in at least 2 of the 3 rabbits.

Skin inflammation would also be considered significant if it persists in at least 2 animals at the end of the observation time. Persistence of hyperplasia, desquamation, discoloration, fissures,escharformation or alopecia is taken into account in determining this.

If full thickness destruction of the skin occurs in at least one rabbit, the test article would be classified as corrosive and would attract the risk phrase "R34 Causes bums".

 

Results. The treated skin site on the animal used in the preliminary screen remained free from signs of irritation throughout the observation period. However, slight or well defined erythema was apparent at the treated site on the 2 remaining animals (No 134 and 135) from 24 hours after patch removal. In animal 134, thiserythematousresponse was accompanied by slight oedema.

Forty eight and 72 hours after patch removal, erythema persisted in both animals although the oedema previously noted at the treated site on animal 134 was no longer in evidence. At the final examination, 7 days after dosing, no signs of irritation were apparent at the treated site on any animal.

The individual mean scores, calculated as described before, were as follows:

 

Rabbit number	Erythema	Oedema
128 134 135	0.0 1.3 2.0	0.0 0.3 0.0

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions, the test material induced a slight irritation being reversible within 7 days of dosing and therefore does not require classification for skin irritation.

Executive summary:

Introduction.The purpose of this study was to assess the degree of irritation produced by the test article, ST 02 C 94, when applied to the intact skin of the albino rabbit. The procedures used were in accordance with the EU Method B.4, as described in Document L383 A, an annex to EEC Commission Directive 92/69/EEC of 31st July 1992 and with Classification and labelling requirements were determined in accordance with Commission Directive 93/21/EEC of 27th April 1993.

 

Methods. Initially, one animal only was dosed in a preliminary screen in order to estimate the potential irritancy of the test article. Twenty four hours after dosing, there was no irritation at the treated site on this first rabbit and 2 further animals were dosed, bringing the total number of rabbits used in the study to 3.

A 0.5 mL aliquot of the test article was applied over a previously clipped area of about 6 cm² of the intact dorsal skin of each rabbit. The test article was held in contact with the skin, under a semi-occlusive patch assembly, for a 4 hour period. The patches were then removed and the skin reaction assessed after one, 24, 48 and 72 hours. As an irritant response persisted in 2 animals 72 hours after patch removal, an additional examination was made 7 days after dosing.

Dermal application of the test article produced no signs of skin irritation in the animal used in the preliminary screen. In the remaining 2 animals, slight or moderate erythema was apparent at the treated site from 24 hours after dosing. Very slight oedema was also noted in one of these animals at this time. The erythema persisted in both animals at the 48 and 72 hour examinations but was no longer apparent at the final examination, 7 days after dosing.

The individual mean scores for erythema and oedema, calculated from the values recorded at the 24, 48 and 72 hour examinations are as follows:

 

Rabbit number	Erythema	Oedema
128 134 135	0.0 1.3 2.0	0.0 0.3 0.0

 

Since in 2 of the 3 rabbits the individual mean scores were less than 2.0, the inflammation produced by the test article is not deemed to be significant (as defined in Commission Directive 93/21/EEC).

 

Conclusions. The test article, ST 02 C 94, does not require labelling according to the Regulation (EEC) No 1272/2008 (CLP).