3,5-dimethylpyrazole

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

5th - 8th April 1994.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

: shorter observation period.

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

not applicable

Principles of method if other than guideline:

The observation period was only for 4 days.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3,5-dimethylpyrazole

EC Number:

200-657-5

EC Name:

3,5-dimethylpyrazole

Cas Number:

67-51-6

Molecular formula:

C5H8N2

IUPAC Name:

3,5-dimethyl-1H-pyrazole

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Appearance: White crystalline powder
Storage conditions: Room temperature in the dark.
Date received: 11th February 1994.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Froxfield Ltd. (U.K), Petersfield, Hampshire, England.
- Age at study initiation: 11 to 13 weeks.
- Weight at study initiation: 2.6 to 3.1 kg.
- Housing: Individually in plastic cages with perforated floors.
- Diet (e.g. ad libitum): Standard laboratory diet SDS Stanrab (P) Rabbit Diet, as libitum.
- Water (e.g. ad libitum): Drinking water, ad libitum.
- Acclimation period: Period not reported, however animals were allowed to acclimatise to the test conditions prior to testing.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): approx. 19ºC.
- Humidity (%): 30-70%.
- Air changes (per hr): 19 charges per hour.
- Photoperiod (hrs dark / hrs light): 12 hour of artificial light (0700-1900) in each 24 hour period.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

no

Amount / concentration applied:

Single dose of 0.5g

Duration of treatment / exposure:

Four hours.

Observation period:

Four days.

Number of animals:

Three

Details on study design:

TEST SITE
- Area: Dorso-lumbar region.
- Area of exposure: Approximately 25 mm x 25 mm.
- Site was prepared 24 hours prior to exposure.
- Type of wrap if used: gauze pad and an 'Elastoplast' dressing.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes with warm water (30 - 40 ºC)
- Time after start of exposure: 4 hours, the end of the exposure period.

SCORING SYSTEM: Draize scale (1977) as seen in table 1 in the field "any other information on material and methods incl. tables".

OBSERVATIONS:
- Clinical signs: animals were observed daily for signs of ill health or toxicity.
- The dermal response was scored at the following time point; 60 mins after removal of dressing and 24, 48 and 72 hours after 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

Remarks on result:

other: No reaction observed at any time point.

Results 2

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: No reaction observed at any time point.

Results 3

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: No reaction observed at any time point.

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: No reaction observed at any time point.

Results 5

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: No reaction observed at any time point.

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: No reaction observed at any time point.

Other effects:

Clinical signs: no signs of toxicity or ill health in any animal during the observation period.
Dermal response: no dermal reaction was observed in any of the test animals.

Any other information on results incl. tables

Table 2. Dermal Response

		Observation Time
Rabbit Number	Observation	60 min	Day 2	Day 3	Day 4
366	Erythema	0	0	0	0
	Oedema	0	0	0	0
367	Erythema	0	0	0	0
	Oedema	0	0	0	0
368	Erythema	0	0	0	0
	Oedema	0	0	0	0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

There was no dermal response or signs of toxicity were observed in any of the test animals after a 4 hour exposure.

Executive summary:

In a GLP compliant study performed according to the standardised guideline EU Method B.4 the dermal response caused by exposure to the test material was determined. Three New Zealand White rabbits were exposed to the test material for 4 hours; the reaction was scored according to the Draize scale (1997), over a 4 day observation period. No dermal response or clinical signs of toxicity were observed in any of the test animals. It is this lack of any reaction which is thought to be the reason the observations were terminated after only 4 days.

The skin irritation study indicates that the test material does not require classification according to Regulation (EC) 1272/2008.