Ethyl cyanoacetate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP LAB testing

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4100 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl cyanoacetate

EC Number:

203-309-0

EC Name:

Ethyl cyanoacetate

Cas Number:

105-56-6

Molecular formula:

C5H7NO2

IUPAC Name:

ethyl 2-cyanoacetate

Details on test material:

Purity: 99.7%
Appearance: Clear liquid
Storage conditions: Room temperature in the dark

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

Twenty healthy female nulliparous and non-pregnant albino guinea-pigs of the Dunkin/Hartley strain were obtained.
The animals were in the weight range of 320 to 377 g on arrival and approximately six to seven weeks of age. All the guinea-pigs were acclimatised to the experimental environment for 6 days prior to allocation to the main study.
An additional three animals, from the same supplier, were used for the preliminary investigations. The animals for the main study were allocated without conscious bias to two groups as follows:
The guinea-pigs were housed in groups of five in suspended metal cages with wire mesh floors in Building R 17 Room 14.
A vitamin C enriched guinea-pig diet FD I and drinking water were provided ad libitum. Hay was given weekly.
The batch of diet used for the study was not analysed for nutrients, possible contaminants or micro­ organisms.
Results of routine physical and chemical examination of drinking water at source, as conducted usually weekly by the supplier, are made available to Huntingdon Research Centre Ltd. as quarterly summaries.
Animal room temperature was maintained at approximately 21 oc and relative humidity at 30 - 70%. These environmental parameters were recorded daily. Air exchange was maintained at approximately 15 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.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

no data

Induction 2

Concentration / amount:

0.5 ml

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

no data

Challenge 2

Concentration / amount:

0.5 ml

No. of animals per dose:

10

Details on study design:

The procedure may be considered in two parts, Induction and Challenge.
Induction - test animals
Prior to each induction application, the skin on the left shoulder region of the guinea-pig was clipped free of hair using electric clippers.
A 20 x 20 mm patch of surgical gauze (three layers thick) was saturated with approximately 0.5 ml of Ethyl cyanoacetate (ECYAD), as supplied.
The patch was placed on the skin and covered by a length of impermeable plastic adhesive tape (50 mm width "Blenderm"). This in turn was firmly secured by elastic adhesive bandage (50 mm width "Elastoplast") wound round the torso of the animal and fixed with "Sleek" impervious plastic adhesive tape. Contact with the skin was maintained for approximately 6 hours for each induction exposure. The dressings were then removed and the resulting dermal reactions assessed approximately 24 hours later (Table 1).
One induction application was made in this manner on Days 1, 8 and 15 so a total of three induction applications were given.
Induction- control animals
During the induction phase, the control animals were treated similarly to the test animals with the exception that the test compound was omitted from the induction applications.
The dermal reactions observed approximately 24 hours after each induction application in both control and test animals were recorded.
Challenge - control and test animals
The control and test animals were challenged topically two weeks after the final induction application using Ethyl cyanoacetate (ECY AD), as supplied.
Hair was removed by clipping from a 50 x 50 mm area on the right flank of each guinea-pig. A 20 x 20 mm gauze patch (three layers thick) was saturated with approximately 0.5 ml of the test substance in a similar fashion to that used for the induction applications.
The patch was sealed to the flank under a 5 em strip of "Blenderm" covered by "Elastoplast" wound round the trunk and secured with "Sleek". Dressings were left in place for approximately 6 hours after which time they were removed.

Challenge controls:

The control and test animals were challenged topically two weeks after the final induction application using Ethyl cyanoacetate (ECY AD), as supplied.

Positive control substance(s):

yes

Remarks:

formalin

Results and discussion

Positive control results:

The sensitivity of the guinea-pig strain used is checked periodically at HRC with formalin, a known sensitiser. All results of recent tests showed reaction.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

72

Group:

test chemical

Dose level:

0.5ml

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 72.0. Group: test group. Dose level: 0.5ml. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 2

Reading:

1st reading

Hours after challenge:

72

Group:

positive control

Dose level:

15%

No. with + reactions:

10

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 72.0. Group: positive control. Dose level: 15%. No with. + reactions: 10.0. Total no. in groups: 10.0.

Any other information on results incl. tables

Guinea-pignumber	E=Erythema0=Oedema	Response toinductionapplications
		1                 2                3
4750	E 0	0 0	0 0	0 0
4751	E 0	0 0	0 0	0 0
4752	E 0	0 0	0 0	0 0
4753	E 0	0 0	0 0	0 0
4754	E 0	0 0	0 0	0 0
4755	E 0	0 0	0 0	0 0
4756	E 0	0 0	0 0	0 0
4757	E 0	0 0	0 0	0 0
4758	E 0	0 0	0 0	0 0
4759	E 0	0 0	0 0	0 0

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU