2-methylbutene

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP, available as unpublished report, near guideline study, minor restrictions in design and/or reporting but otherwise adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methyl-2-butene

IUPAC Name:

2-methyl-2-butene

Constituent 2

Reference substance name:

2-methylbut-2-ene

EC Number:

208-156-3

EC Name:

2-methylbut-2-ene

Cas Number:

513-35-9

IUPAC Name:

2-methylbut-2-ene

Details on test material:

- Name of test material (as cited in study report): 2-methyl-2-butene
- Physical state: Strong smelling, colourless liquid with a specific gravity of 0.66
- Stability under test conditions: stable for duration of experiment, expiry date 1 January 1981
- Storage condition of test material: in fridge

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Shell Toxicology Laboratory, Breeding Unit, Tunstall, UK
- Age at study initiation: 4-6 months
- Weight at study initiation: 2982-4208 g males, 3930-4915 g males
- Housing: Individually in hanging stainless steel cages with all mesh floors and tops and half mesh fronts (58 x 43 x 43 cm)
- Diet: SG1 with vitamin C supplement (Grain Harvesters Ltd) ad libitum.
- Water: Filtered public water ad libitum.
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature: 16-19 °C

IN-LIFE DATES: From: 7 May 1980 To: 18 July 1980

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.2 mL

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

6

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: No

SCORING SYSTEM: Initial pain scored on a 1-6 scale. Eye irritation scored according to the Draize scale. Mean total scores transcribed to a grade and descriptive rating using a modification of the Kay and Calandra technique.

TOOL USED TO ASSESS SCORE: fluorescein

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 1 hour, 1, 2, 3 and 7 days

Score:

0.5

Results 2

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 1 hour, 1, 2, 3 and 7 days

Score:

0

Results 3

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 1 hour, 1, 2, 3 and 7 days

Score:

0

Any other information on results incl. tables

Immediately following instillation into the eye, all rabbits showed signs of moderate initial pain (grade 4).

Table 1: Eye irritation scores of 2-methyl-2-butene according to the Draize scheme 

Time (hours)	Cornea						Iris						Conjunctiva
													Redness						Chemosis
1	1	2	3	4	5	6	1	2	3	4	5	6	1	2	3	4	5	6	1	2	3	4	5	6
24	0	0	0	0	0	0	0	0	0	0	0	0	0.5	0	0	0	0	0.5	0	0	0	0	0	0
48	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
72	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
mean 24-72	0						0						0						0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

2-methyl-2-butene was non irritant to the rabbit eye.

Executive summary:

Instillation of 2-methyl-2-butene into the eye resulted in a moderate initial pain response (grade 4) in all animals. The mean total scores for the responses of the conjunctiva, cornea and iris at 1 hour, 1, 2, 3 and 7 days were calculated and were. 0.5, 0, 0, 0 and 0 respectively.

 

2-Methyl-2-butene may be described as non irritating to rabbit eyes.