3,5-dimethylpyrazole

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

07 April 2002 to 16 April 2002

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:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Deviations:

no

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:

- Physical state: Off white powder
- Storage condition of test material: In the dark at ambient temperature

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Age at study initiation: Young adults
- Weight at study initiation: On dose day individual animals weighted 3.99, 3.60 and 3.81 kg.
- Housing: Individually in stainless steel cages, approximately 77 x 70 x 48 cm.
- Diet: The feed was supplied ad libitum throughout the study, supplemented with hay twice weekly.
- Water: Water was supplied ad libitum throughout the study from the domestic main supply.
- Analysis for significant contaminants was performed on both the diet and water supplied to the test animals. Both were considered not to contain any additional substances in sufficient concentrations to have any influence on the outcome of the study.
- Acclimation period: At least 5 days prior to study initiation.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Mean minimum and maximum temperatures were 21ºC and 20ºC, respectively.
- Humidity (%): Ranged from 28 to 37% with a mean humidity of 32%.
- Air changes (per hr): Minimum of 15 air charges per hour.
- Photoperiod (hrs dark / hrs light): 12 hr light/dark cycle (light 0700-1900 hrs).

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: left eyer served as control.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 65.2, 64.7 and 63.5 mg was instilled into the eye of rabbits numbered 1, 2 and 3. These are the weight equivalent to 0.1 mL.

Duration of treatment / exposure:

Single dose

Observation period (in vivo):

The initial observation period was 72 hours, which was extended to 8 Days (7 days after exposure) for two rabbits in order to assess reversibility.

Number of animals or in vitro replicates:

3

Details on study design:

APPLCATION OF THE TEST MATERIAL
Ocular examination: Animals were examined before application of the test material and no ocular defects were detected.
Application: The test material was placed into the right eye by gently pulling the lower eyelid away from the eyeball to form a sac into which the test material was dropped. The lid was held together gently for 1 to 2 seconds. One rabbit was treated first to assess the severity of the reaction over 24 hours. As none were noted, the remaining two rabbits were treated in the same manner.
Control: The left eye remained untreated to serve as a control, which as examined in the same manner as the treated eye.

SCORING SYSTEM: Draize scale, see Table 1.
Observation intervals: 1, 24, 48 and 72 hrs and then Day 8.
Viability: Checked twice daily.
Clinical observations: All animals were examined for any reaction to treatment. The onset, intensity and duration of any reactions were recorded.
Body weight: Recorded on Day 0 (day of exposure).

TOOL USED TO ASSESS SCORE: A hand held magnifier and pen torch was used where necessary. To assess corneal damage, fluorescein sodium ophthalmic solution (BP)(2%) was used.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 2

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 3

Irritation parameter:

conjunctivae score

Remarks:

Redness

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.75

Max. score:

3

Reversibility:

fully reversible within: 8 days

Results 4

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.25

Max. score:

4

Reversibility:

fully reversible within: 8 days

Results 5

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.75

Max. score:

4

Reversibility:

fully reversible within: 8 days

Results 6

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.5

Max. score:

2

Reversibility:

fully reversible within: 8 days

Results 7

Irritation parameter:

conjunctivae score

Remarks:

Redness

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.5

Max. score:

3

Reversibility:

fully reversible within: 8 days

Results 8

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.25

Max. score:

4

Reversibility:

fully reversible within: 8 days

Results 9

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 10

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 11

Irritation parameter:

conjunctivae score

Remarks:

Redness

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.75

Max. score:

3

Reversibility:

fully reversible within: 72 hours

Results 12

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.75

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Irritant / corrosive response data:

- Between 1 and 48 hours after treatment corneal opacity was noted in one animal (easily discernible translucent area covering between three quarters and the whole of the cornea). By 72 hours the effect was notably reduced to scattered or diffuse areas of opacity covering between a quarter and a half of the cornea.
- Conjunctival redness and chemosis was noted in all three animals up to 72 hours after instillation.
- Moderate discharge was noted in one animal only 1 hour after instillation and slight to moderate discharge was noted in a second animal up to 48 hours after application of the test material.
- No responses were noted in the control eye.

Any other information on results incl. tables

Table 2. Reaction Scores for Treated and Control Eyes

Area of Eye			Animal No. 1					Animal No. 2					Animal No. 3
			Time after instillation of the Test Material (hours/days)
			1hr	24hr	48hr	72hr	Day 8	1hr	24hr	48hr	72hr	Day 8	1hr	24hr	48hr	72hr
Test Eye
Cornea:	Degree/Opacity		0	0	0	0	0	2	2	2	1	0	0	0	0	0
	Area/Opacity		0F	0	0	0	0	4F	4F	4F	2F	0F	0F	0	0	0
Iris			0	0	0	0	0	0	0	0	0	0	0	0	0	0
Conjunctivae:	Redness		2	2	2	1	0	2	2	1	1	0	1	1	1	0
	Chemosis		2	1	1	1	0	2	1	1	1	0	2	1	0	0
Discharge			2	0	0	0	0	1	2	1	0	0	0	0	0	0
Control Eye
Cornea:		Degree/Opacity	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Area/Opacity	0F	0	0	0	0	0F	0F	0F	0F	0F	0F	0	0	0
Iris			0	0	0	0	0	0	0	0	0	0	0	0	0	0
Conjunctivae:		Redness	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Chemosis	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Discharge			0		0	0	0	0	0	0	0	0	0	0	0	0

F = Fluorescein stanied

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the test, the test material is considered to be non-irritating to the eye in rabbits. Exposure to the test material caused some mild reactions, however these reactions were not severe enough to permit classification. Corneal opacity was noted in one animal between up to 72 hrs post application, conjunctivae redness and discharge was observed in all three animals, however these reactions were mild and fully reversible by Day 8.

Executive summary:

The irritation potential of the test material was assessed in an acute eye irritation study, performed to GLP and in line with the standardised guidelines OCED 405, EU Method b.5 and EPA OPPTS 870.2400.

The weight equivalent to 1 mL of the test material was applied to the right eye of three New Zealand White rabbits, the contra-lateral eye serving as an untreated control. The initial observation period was 72 hours, which was extended to 8 Days (7 days after exposure) for two rabbits in order to assess the reversibility of any reactions.

Exposure to the test material caused some mild reactions, however these reactions were not severe enough to permit classification. Corneal opacity was noted in one animal between up to 72 hrs post application, conjunctivae redness and discharge was observed in all three animals, however these reactions were mild and fully reversible by Day 8.

Under the conditions of the test, the test material is considered to be non-irritating to the eye in rabbits.