Tungsten disulphide

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

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:

Tungsten

EC Number:

231-143-9

EC Name:

Tungsten

Cas Number:

7440-33-7

Molecular formula:

W

IUPAC Name:

tungsten

Constituent 2

Reference substance name:

Sulfur

EC Number:

231-722-6

EC Name:

Sulfur

Cas Number:

7704-34-9

Molecular formula:

S

IUPAC Name:

sulfur

Test material form:

solid: particulate/powder

Details on test material:

- Particle size distribution: D50= 3.1 um; D90=6.5 um
- Mass median aerodynamic diameter (MMAD):
- Density: 7.69 g/cm3

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Kisslegg, Germany
- Age at study initiation: at least 6 weeks
- Weight at study initiation: between 1.0 and 3.5 kg
- Housing: Individually in labelled cages with perforated floors
- Diet (e.g. ad libitum): Standard laboratory rabbit diet (Charles River Breeding and Maintenance Diet for Rabbits, Altromin, Germany) approx. 100 g. per day
- Water (e.g. ad libitum): Free access to tap-water
- Acclimation period: at least 5 days before start of treatment

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±3°C
- Humidity (%): 30-70%
- Air changes (per hr): 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours artificial fluorescent light and 12 hours dark per day

IN-LIFE DATES: From: To:

Test system

Vehicle:

not specified

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):93.6 (93.4 - 93.8) mg of the test substance (a volume of approximately 0.1 ml)

Duration of treatment / exposure:

24 h

Observation period (in vivo):

1, 24, 48 and 72 hours after instillation of the test substance

Number of animals or in vitro replicates:

3 animals of one sex

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): approximately 50 ml tepid tap-water
- Time after start of exposure: 24 h

SCORING SYSTEM:
CORNEAL IRRITATION
Opacity: degree of density (area most dense taken for reading)
No ulceration or opacity (may include slight dulling of normal lustre)..........................................O
Scattered or diffuse areas of opacity, details of iris clearly visible............................................ 1
Easily discernible translucent area, details of iris slightly obscured.......................................... 2
Nacreous area, no details of iris visible, size of pupil barely discernible.................................... 3
Opaque cornea, iris not discernible through the opacity............................................................ 4

Area of cornea involved:
No ulceration or opacity............................................................................................................O
One quarter or less but not zero................................................................................................. 1
Greater than one quarter, but less than half............................................................................... 2
Greater than half, but less than three quarters........................................................................... 3
Greater than three quarters, up to whole area.......................................................................... 4

IRIS
Normal.......................................................................................................................................... 0
Markedly deepened rugae, congestion, swelling, moderate circumcomeal hyperaemia, or injection, any of these or combination thereof, iris still reacting to light
(sluggish reaction is positive)...................................................................................................... 1
No reaction to light, hemorrhage, gross destruction (any or all of these)...................................2

CONJUNCT/VAL IRRITAT/ON
Redness (refers to palpebrae and sclera, excluding cornea and iris):
Blood vessels normal.................................................................................................................. 0
Some blood vessels definitely hyperaemic (injected)................................................................. 1
Diffuse, crimson color, individual vessels not easily discernible................................................ 2
Diffuse beefy red........................................................................................................................ 3

Chemosis (refers to lids and/or nictitating membranes):
No swelling.................................................................................................................................. 0
Any swelling above normal (includes nictitating membranes).................................................... 1
Obvious swelling with partial eversion of lids............................................................................ 2
Swelling with lids about half closed........................................................................................... 3
Swelling with lids more than half closed .....................................................................................4

Discharge:
No discharge (may include small amounts observed in inner canthus of normal animals).........0
Any amount different from normal and/or lacrimation................................................................. 1
Discharge with moistening of the lids and hairs just adjacent to lids.......................................... 2
Discharge with moistening of the lids and hairs (considerable area around the eye)................3

Where standard lighting is considered inadequate for observing minor effects, eye examinations will be performed using an ophthalmic examination lamp.
In cases of equivocal results when comparing the treated and untreated eyes, the illustrated guide from the Consumer Product Safety Commission, Washington, D.C. 20207 will be used for additional control purposes.


TOOL USED TO ASSESS SCORE: hand-slit lamp

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

iris score

Basis:

mean

Remarks:

Animals: #98, #100, #102

Time point:

24/48/72 h

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

Animals: #98, #100, #102

Time point:

24/48/72 h

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

Animals: #98, #100, #102

Time point:

24/48/72 h

Score:

0.1

Reversibility:

fully reversible within: 24 hrs

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

conjunctivae score

Remarks:

Redness

Basis:

mean

Remarks:

Animals: #98, #100, #102

Time point:

24/48/72 h

Score:

0.3

Reversibility:

fully reversible within: 24 hrs

Remarks on result:

no indication of irritation

Any other information on results incl. tables

TABLE 1: INDIVIDUAL EYE IRRITATION SCORES

		Cornea		Iris		Conjunctivae
Time after dosing	Opacity	Area	Fluor area(%)		Redness	Chemosis	Discharge	Comments
r3No 98#
1 hour	0	0		1	1	2	2	abce
24 hours	0	0	0	0	1	1	0	be
48 hours	0	0		0	0	0	0
72 hours	0	0		0	0	0	0
r3No 100#
1 hour	0	0		1	1	2	2	abce
24 hours	0	0	0	0	1	0	0	be
48 hours	0	0		0	0	0	0
72 hours	0	0		0	0	0	0
r3No 102#
1 hour	0	0		1	2	2	1	abce
24 hours	0	0	0	0	1	0	0
48 hours	0	0		0	0	0	0
72 hours	0	0		0	0	0	0

TABLE 2: MEAN VALUE EYE IRRITATION SCORES

Animal:       Corneal:              

	opacity		Redness	Chemosis
98	0	0	0.3	0.3
100	0	0	0.3	0.0
102	0	0	0.3	0.0

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Based on these results and according to the EC criteria for classification and labelling requirements for dangerous substances and preparations (Guidelines in Commission Directive 93/21/EEC), TUNGSTEN DISULFIDE does not have to be classified and has no obligatory labelling requirement for eye irritation

Executive summary:

The study was carried out based on the guidelines described in: EC Commission Directive 92/69/EEC, B.5, "Acute Toxicity - Eye irritation" and OECD No.405, "Acute Eye Irritation/Corrosion".

 Single samples of approximately 94 mg of TUNGSTEN DISULFIDE (a volume of approximately 0.1 ml) were instilled into one eye of each of three rabbits. Observations were made 1, 24, 48 and 72 hours after instillation.

 Instillation of the test substance resulted in effects on the iris and conjunctivae.

lridial irritation (grade 1) was observed in all animals and had resolved within 24 hours. Irritation of the conjunctivae was seen as redness, chemosis and discharge, which had completely resolved within 48 hours in all animals. Grey staining of (peri) ocular tissues by the test substance was observed on day 1. Due to this staining, the eyelids, nictitating membrane and sclera could be scored partly (upper part).

Remnants of the test substance were present in the eyes of two animals on days 1 and 2 and in one animal on day 1. Remnants of the test substance were present on the outside of the eyelids of two animals on days 1 and 2 and of one animal on day 1. Grey staining of the fur on the head and paws, caused by the test substance, was noted on day 1.

 Based on these results and according to the EC criteria for classification and labelling requirements for dangerous substances and preparations (Guidelines in Commission Directive 93/21/EEC), TUNGSTEN DISULFIDE does not have to be classified and has no obligatory labelling requirement for eye irritation.