Methyl isothiocyanate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study (OECD 405)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

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:

other: EPA - Pesticide assessment guidelines

Deviations:

not specified

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methyl isothiocyanate

EC Number:

209-132-5

EC Name:

Methyl isothiocyanate

Cas Number:

556-61-6

Molecular formula:

C2H3NS

IUPAC Name:

isothiocyanatomethane

Details on test material:

Test article name : METHYLSENFOEL (MITC)
Source: DEGUSSA AG
Purity: technical

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Kleintierfarm Madoerin AG (Ch4414 Fuellinsdorf, Switzerland)
- Age at study initiation: 15-16 weeks
- Weight at study initiation: 2.1-2.2 weeks
- Housing: individually in stainless steel cages aquipped with an automatic cleaning and drinking system.
- Diet (e.g. ad libitum): pelleted standard kliba 341, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-2
- Humidity (%): 55+/-10
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12 (8h music/light period)

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: the right eye (untreated eye) of each animal

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml/animal
- Concentration (if solution): no data

VEHICLE : no

Duration of treatment / exposure:

a single dose was administered to the left eye of each animal.

Observation period (in vivo):

72 hours.
According to the results observed and due to ethical reasons the test was terminated after an observation period of 72 hours.

Number of animals or in vitro replicates:

3 = 2 females + 1 male

Details on study design:

REMOVAL OF TEST SUBSTANCE : NO
SCORING SYSTEM: the same in guideline of OECD (405)
TOOL USED TO ASSESS SCORE: a slit-lamp 30 SL and a Varta Cliptrix diagnostic-lamp.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Remarks:

(opacity)

Basis:

mean

Remarks:

3 animals

Time point:

other: 24-72 hours

Score:

2.66

Max. score:

4

Reversibility:

other: not examined

Remarks on result:

other: Individual scores: 3, 2, 3.

Results 2

Irritation parameter:

iris score

Basis:

mean

Remarks:

3 animals

Time point:

other: 24-72 hours

Score:

1.67

Max. score:

2

Reversibility:

other: not examined

Remarks on result:

other: Individual scores: 2, 1, 2.

Results 3

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

mean

Remarks:

3 animals

Time point:

other: 24-72 hours

Score:

3

Max. score:

3

Reversibility:

other: not examined

Remarks on result:

other: Individual scores: 3, 3, 3.

Results 4

Irritation parameter:

conjunctivae score

Remarks:

(chemosis)

Basis:

mean

Remarks:

3 animals

Time point:

other: 24-72 hours

Score:

3.47

Max. score:

4

Reversibility:

other: not examined

Remarks on result:

other: Individual scores: 3.7, 3, 3.7

Irritant / corrosive response data:

MITC to the eyes of rabbits produced severe inflammation including corneal opacity, iritis and conjunctival swelling. The mean value of the scores for each type of lesion, calculated for each animal separately, from 24 to 72 hours. See table.
Corrosion of the cornea and conjuntivae was observed at each of the measuring intervals.

Other effects:

Slight sedation was observed in all animals at day one of test. No other acute toxic symptoms were observed in the animal during the remaining test period, and no mortality occurred. The body weight gain of all rabbits was similar.
In the area of application, no discoloration of the cornea and conjunctivae which could be related to effects of MITC was observed.
Due to the results obtained, no macroscopic organ examination was indicated.

Any other information on results incl. tables

Table of results (MITC) :

Animal	Mean 24-72h
	Cornea opacity	Iris	Conjunctivae
			Redness	Chemosis
1 – male	3	2	3	3.7
2 – female	2	1	3	3
3 – female	3	2	3	3.7

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye)

Remarks:

Migrated information Criteria used for interpretation of results: other: Regulation EC no.1272/2008

Conclusions:

MITC induced risk of serious damage to eyes, it was highly irritating.

Executive summary:

The purpose of this primary eye irritation study was to assess possible irritation potential when single doses of MITC are placed in the conjunctival sac of rabbit eyes.

MITC to the eyes of rabbits produced severe inflammation including corneal opacity, iritis and conjunctival swelling.

In the area of application no discoloration of the cornea and conjunctivae was observed which could be related to effects of MITC.

The mean value of the scores of 3 rabbits at 24/72 hours were: Score of cornea opacity =2.66/4, score of iritis = 1.67/2, redness score =3/3 and chemosis score =3.47/4.

Slight sedation was observed in all animals at day one of test. No other acute toxic symptoms were observed in the animal during the remaining test period, and no mortality occurred. The body weight gain of all rabbits was similar.

To sum up, MITC induced risk of serious damage to eyes, it was highly irritating.