Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1998-02-24 to 1999-06-24
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
ell documented, scientifically sound study that was conducted accordiing to GLP and OECD guideline 402.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999
Reference Type:
publication
Title:
SIDS Initial Assessment Report for SIAM 21 for Tungsten Carbide (12070-12-1), Washington DC,18-20 October, 2005
Author:
OECD-SIDS
Year:
2005
Bibliographic source:
UNEP Publications
Report Date:
2005

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Tungsten Carbide Powder - Pure
- Physical state: Grey powder
- Analytical purity: >99.98%
- Storage condition of test material: Room temperature

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan UK Ltd Bicester Oxon England
- Age at study initiation: 8-11 weeks
- Weight at study initiation: 208-255g
- Housing: Individually in metal cages with wire mesh floors
- Diet (e.g. ad libitum): ad lib - Special Diet Services RM1(E) SQC expanded pellet
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-22.5
- Humidity (%): 29-52%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12 (0700 - 1900 hours)

IN-LIFE DATES: From: 1998-02-24 To: 1998-03-10

Administration / exposure

Type of coverage:
occlusive
Vehicle:
other: methylcellulose
Details on dermal exposure:
TEST SITE
- Area of exposure: Dorso-lumbar region
- % coverage: 10%
- Type of wrap if used: Porous gauze held in place with a non-irritating dressing covered with a waterproof dressing encircling trunk of animal.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Warm water (30 to 40 degrees C) to remove residual test substance. The treated area was blotted dry with absorbent paper.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2 mL/kg bodyweight
- Concentration (if solution): 100% w/v in 1% w/v aqueous methylcellulose
- Constant volume or concentration used: Yes

VEHICLE
- Amount(s) applied (volume or weight with unit): 1% w/v aqueous methylcellulose
Duration of exposure:
24 hours
Doses:
2000 mg/kg bw
No. of animals per sex per dose:
5 males and five females
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Cages of rats were checked at least twice daily for any mortalities
- Necropsy of survivors performed: Yes
- Other examinations performed: Clinical signs, body weight

CLINICAL SIGNS:
Animals were observed soon after dosing and at frequent intervals for the remainder of Day 1. On subsequent days animals were observed once in the morning and again at the end of the experimental day (with the exception of Day 15 - morning only). The nature and severity of the clinical signs and time were recorded at each observation.

BODYWEIGHT:
The bodyweight of each rat was recorded on Days 1 (prior to dosing), 8 and 15. Individual weekly bodyweight changes and group mean bodyweights were calculated.

TERMINAL STUDIES:
-Macroscopic pathology- All animals were subjected to a macroscopic examination which consisted of opening the abdominal and thoracic cavities. The macroscopic appearance of all tissues was recorded and macroscopic abnormalities were preserved.
Statistics:
no data

Results and discussion

Effect levelsopen allclose all
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Key result
Sex:
male/female
Dose descriptor:
other: NOEL
Effect level:
> 2 000 mg/kg bw
Mortality:
No deaths occurred.
Clinical signs:
No evidence of a systemic response in any animal throughout the study following a single dose application of Tungsten Carbide Powder - pure.
Body weight:
All rats achieved satisfactory weight gains throughout the study.
Gross pathology:
No macroscopic abnormalities were observed for animals killed at study termination on Day 15.
Other findings:
No dermal irritation was seen in any animal during the study.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The NOEL and acute lethal dose to rats of Tungsten Carbide Powder- Pure was demonstrated to be greater than 2000 mg/kg bodyweight.