Benzyltoluene

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The GLP study was conducted according to an internationally accepted guideline. All study parameters are given in detail. Nevertheless, according to the ECHA's practical guide 6: "How to report read-across and categories" the maximum for read-cross is 2.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

SAS-305

IUPAC Name:

SAS-305

Test material form:

other: liquid

Details on test material:

Description: clear, colourless liquid
SAS-305 is a mixture of 3 isomeric structures.
Composition:
1-Methylethyl-4-(1-phenylethyl)benzene
1-Methylethyl-3-(1-phenylethyl)benzene
1-Methylethyl-2-(1-phenylethyl)benzene

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Three New Zealand White rabbits, supplied by David Percival Ltd, Moston, Sandbacn, Cheshire, UK, were used. At the start of the study the animals weighed 2.70 to 3.07 kg and were twelve to sixteen weeks old. After a minimum acclimatisation period of five days each animal was given a number unique within the study which was written with a black indelible marker-pen on the inner surface of the ear and on the cage label.

The animals were individually housed in suspended metal cages. Free access to mains drinking water and food (STANRAB SQC Rabbit Diet, Special Diets Services Ltd, Witham, Essex, UK) was allowed throughout the study.

The animal room was maintained at a temperature of 1 7 to 19 o C and relative humidity of 45 to 52%. The rate of air exchange was approximately fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light and twelve hours darkness.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.1 ml

Duration of treatment / exposure:

72 hours

Observation period (in vivo):

72 hours

Number of animals or in vitro replicates:

3

Details on study design:

Immediately before the start of the test, both eyes of the provisionally selected test rabbits were examined for evidence of ocular irritation or defect with the aid of a light source from a standard ophthalmoscope. Animals showing evidence of ocular lesions were rejected and replaced.

One rabbit was initially treated. A volume of 0.1 ml of the test material was instilled into the conjunctival sac of the right eye, formed by gently pulling the lower lid away from the eyeball. The upper and lower eyelids were held together for about one second immediately after instillation, to prevent loss of the test material, and then released. The left eye remained untreated and was used for control purposes. Immediately after administration of the test material, an assessment of the initial pain reaction was made.
After consideration of the ocular responses produced in the first treated animal, two additional animals were treated.

Assessment of ocular damage/irritation was made approximately 1 hour and 24, 48 and 72 hours following treatment, according to the numerical evaluation given in Appendix I, (from Draize J H (1977) "Dermal and Eye Toxicity Tests" In: Principles and Procedures for Evaluating the Toxicity of Household Substances, National Academy of Sciences, Washington DC p.48 to 49).

Any other ocular effects were also noted. Examination of the eye was facilitated by the use of the light source from a standard ophthalmoscope.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 48

Results 2

Irritation parameter:

conjunctivae score

Basis:

animal: 1 and 2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 3

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 4

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 5

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 6

Irritation parameter:

maximum mean total score (MMTS)

Basis:

mean

Time point:

other: 72 hours

Score:

1.3

Max. score:

110

Reversibility:

fully reversible

Any other information on results incl. tables

Rabbit Number andSex (Bodyweighl kg)		Time After Treatment	Corneal Opacity	Iridial Inflammation	Conjunctival Redness	ConjunctivalChemosis
126 Male		24Hours	0	0	1	0
		48 Hours	0	0	0	0
(2.70)		72 Hours	0	0	0	0
	Total		0	0	1	0
	Mean		0.0	0.0	0.3	0.0
582 Male		24 Hours	0	0	0	0
		48Hours	0	0	0	0
(2.73)		72 Hours	^0	0	0	0
	Total		0	0	0	0
	Mean		0.0	0.0	0.0	0.0
20 Male		24 Hours	0	0	0	0
		48Hours	0	0	0	0
(3.07)		72 Hours	0	0	0	0
	Total		0	0	0	0
	Mean		0.0	0.0	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:

The test material did not produce positive results in any rabbit according to the EU labelling regulations.

Executive summary:

A study was performed to assess the irritancy potential of the test material to the eye of the New Zealand White rabbit. The method used followed that described in the OECD Guidelines for Testing of Chemicals No. 405 "Acute Eye Irritation/Corrosion" (adopted 24 February 1987) and Method B5 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

A single instillation of the test material to the non-irrigated eye of three rabbits produced minimal conjunctival irritation in two treated eyes. 3.The test material produced a maximum group mean score of 1.3. The test material did not meet the criteria for classification as irritant according to EU labelling regulations.