Tungsten disulphide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-11-28, 2001-12-14

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:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

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

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 16031/01
- Expiration date of the lot/batch:01 April 2002
- Purity: >98%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature in the dark
- Stability under test conditions:Stable
- Solubility and stability of the test substance in the solvent/vehicle: 1% Aq. Carboxymethyl cellulose- not indicated

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:The formulations (w/w) were prepared within 4 hours prior to dosing. Homogeneity was accomplished to a visually acceptable level.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: approx. 7 weeks old
- Weight at study initiation: average of 166g for females and average of 252g for males
- Fasting period before study: Food was withheld overnight (for a maximum of 20 hours) prior to dosing until approximately 3-4 hours after administration of the test substance.
- Housing:Group housing of 3 animals per sex per cage in labelled Macrolon cages (type IV; height 15 cm.) containing purified sawdust as bedding material
- Diet (e.g. ad libitum): Free access to standard pelleted laboratory animal diet (from Altromin (code VRF 1)
- Water (e.g. ad libitum):Free access to tap-water
- Acclimation period:at least 5 days before start of treatment under laboratory conditions

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±3°C
- Humidity (%): relative humidity of 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

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

1% Aq. Carboxymethyl cellulose

Doses:

single dose

No. of animals per sex per dose:

three Winstar rats of each sex at each dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:At periodic intervals on the day of dosing (day 1) and once daily thereafter, until day 15
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,Mortality/Niability, Necropsy

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Lethargy and/or piloerection were noted among the females on day 1. One male showed lethargy on day 1. No clinical signs of systemic toxicity were noted among the other males.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The oral LD50 value of tungsten disulphide in Wistar rats was established to exceed 2000 mg/kg body weight.

Executive summary:

The study was carried out based on the guidelines described in: EC Commission Directive 96/54/EC, Part B.1 tris "Acute Toxicity-Oral, Acute Toxic Class Method" and OECD No.423, "Acute Oral Toxicity-Acute Toxic Class Method". Tungsten disulphide was administered by oral gavage to three Wistar rats of each sex at 2000 mg/kg body weight. Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed after terminal sacrifice (day 15). No mortality occurred. The oral LD50 value of tungsten disulphide in Wistar rats was established to exceed 2000mg/kg body weight.