Tungsten hexafluoride

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The EU RAR contains a review and summary of available data on HF. The studies compiled in this report were assessed as part of the EU RAR and are therefore considered to be suitably reliable. The same test was reviewed and assessed in a SCIENCE REPORT by the UK Environment Agency and also considered as reliable. Test done under GLP conditions. Read across justification is given in section 13 assessment reports: WF6 justification for read across

Data source

Reference

Reference 1

Reference Type:

review article or handbook

Title:

European Union Risk Assessment Report HYDROGEN FLUORIDE

Author:

European Commission

Year:

2001

Bibliographic source:

published article European Union Risk Assessment Report, Volume 8, Institute for Health and Consumer Protection, European Chemicals Bureau. (http://europa.eu.int)

Reference 2

Reference Type:

review article or handbook

Title:

SCIENCE REPORT A Review of the Toxicity and Environmental Behaviour of Hydrogen Fluoride in Air

Author:

Environment Agency

Year:

2005

Bibliographic source:

http://www.fluoridealert.org/wp-content/uploads/uk.hf_.2006.pdf

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 412 (Subacute Inhalation Toxicity: 28-Day Study)

Principles of method if other than guideline:

In a range-finding study, groups of five male and five female Fischer 344 rats were exposed to measured concentrations of 0, 1, 10, 25, 65 or 100 ppm (0, 0.83, 8.3, 21, 54 and 83 mg/m3) for 6 hours/day, 5 days/week, for 2 weeks; survivors were sacrificed 2 days later. 10 exposures within 15 days.

GLP compliance:

not specified

Remarks:

As per EU RAR on HF study reported to be GLP complaint.

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hydrogen fluoride

EC Number:

231-634-8

EC Name:

Hydrogen fluoride

Cas Number:

7664-39-3

IUPAC Name:

fluoride

Test material form:

other: gaseous

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Administration / exposure

Route of administration:

inhalation: gas

Type of inhalation exposure:

not specified

Vehicle:

air

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

6 hours

Frequency of treatment:

5 days/week for 2 weeks

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
1 ppm (0,83 mg/m³)
Basis:
analytical conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
10 ppm (8,3 mg/m³)
Basis:
analytical conc.

Doses / concentrations 3

Remarks:

Doses / Concentrations:
25 ppm (21 mg/m³)
Basis:
analytical conc.

Doses / concentrations 4

Remarks:

Doses / Concentrations:
65 ppm (54 mg/m³)
Basis:
analytical conc.

Doses / concentrations 5

Remarks:

Doses / Concentrations:
100 ppm (83 mg/m³)
Basis:
analytical conc.

No. of animals per sex per dose:

five male and five female

Control animals:

yes

Results and discussion

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

1 ppm (analytical)

Based on:

test mat.

Sex:

male/female

2

Dose descriptor:

NOAEL

Effect level:

0.83 mg/m³ air (analytical)

Based on:

test mat.

Sex:

male/female

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

NOAEL for HF is 1 ppm which equals 0.17 ppm of WF6 and 2.1 mg/m³ WF6 at 20 °C and 1,013 bar.

Executive summary:

In a range-finding study, groups of five male and five female Fischer 344 rats were exposed to measured concentrations of 0, 1, 10, 25, 65 or 100 ppm (0, 0.83, 8.3, 21, 54 and 83 mg/m³) for 6 hours/day, 5 days/week, for 2 weeks; survivors were sacrificed 2 days later (Placke et al, 1990). Exposures to 25 ppm (21 mg/m³) and above resulted in deaths of all females, with deaths beginning on the eighth, third, and second day of exposure at the 25, 65, and 100 ppm (21, 54 and 83 mg/m³) concentrations, respectively. Exposures to 65 and 100 ppm (54 and 83 mg/m³) resulted in deaths of all males, with deaths beginning on the third and second day at the 65 and 100 ppm concentrations, respectively. No deaths occurred during the first day of exposure at any concentration, and no deaths occurred at the lower concentrations.