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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:
Well documented, scientifically sound study that was conducted in accordance to GLP and OECD guideline 402 with no deviation to the protocol.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report date:
1999

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
Ammonium wolframate
EC Number:
234-364-9
EC Name:
Ammonium wolframate
Cas Number:
11120-25-5
Molecular formula:
(NH4)10H2W12O42*4H2O
IUPAC Name:
Ammonium (para)tungstate
Constituent 2
Reference substance name:
Ammonium paratungstate
IUPAC Name:
Ammonium paratungstate
Details on test material:
- Name of test material (as cited in study report): Ammonium Paratungstate (CAS# as cited in study: 12028-06-7)
- Physical state: White powder
- Analytical purity: >99.9%
- Storage condition of test material: Room temperature

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan UK Ltd, Bicester, Oxon, England
- Age at study initiation: 8 to 11 weeks
- Weight at study initiation: 214 to 245 g
- Housing: Individually in metal cages with wire mesh floors.
- Diet (eg ad libitum): Special Diet ServicesRM1(E) SQC expanded pellet- ad libitum
- Water (eg ad libitum): ad libitum
- Acclimation period: 5 days

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

IN-LIFE DATES: From: February 24, 1998 To:March 10, 1998

Administration / exposure

Type of coverage:
occlusive
Vehicle:
other: 1% w/v aqueous methylcellulose
Details on dermal exposure:
TEST SITE
- Area of exposure: Dorso-lumbar region
- % coverage: 10 %
- Type of wrap if used: The treatment area (approximately 50 mm x 50 mm) was covered with porous gauze with a waterproof dressing encircled firmly around the trunk of the animal.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Washed with warm water (30 to 40 °C)
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bodyweight; maximum practical concentration of 200% w/v in 1% aqueous methylcellulose and administered at a dose volume of 1 mL/kg bodyweight.
- Constant volume or concentration used: Yes

VEHICLE
- Concentration (if solution): 1 % w/v aqueous methylcellulose
Duration of exposure:
24 hours
Doses:
Single dose of 2000 mg/kg bodyweight
No. of animals per sex per dose:
5 males and 5 females
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: Yes, all animals were killed on Day 15
- Mortality: Cages of rats were checked at least twice daily for any mortalities.
- 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 of the clinical signs and time were recorded at each observation.
- Dermal responses: Local dermal irritation at the treatment site was assessed daily using the numerical scoring system presented below.
- 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.
- 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 levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Mortality:
There were no deaths.
The acute lethal dose to rats of Ammonium paratungstate was demonstrated to be greater than 2000 mg/kg bodyweight.
Clinical signs:
other: There was no evidence of a systemic response in any animal throughout the study period.
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 acute lethal dermal dose to rats of ammonium paratungstate was demonstrated to be greater than 2000 mg/kg bodyweight.

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