Tungsten disilicide

Flammability

Administrative data

Endpoint:

flammable solids

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.6315 (Flammability)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.10 (Flammability (Solids))

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Tungsten disilicide

EC Number:

234-909-0

EC Name:

Tungsten disilicide

Cas Number:

12039-88-2

Molecular formula:

Si2W

IUPAC Name:

Tungsten disilicide

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Batch number: 171130

Results and discussion

Flammable solids

Test procedure:

burning rate test: preliminary screening test

Remarks on result:

other: combustion along the powder train was observed only up to 12 cm within 4 minutes

Any other information on results incl. tables

The test item was filled into a mould of 250 mm length, with a triangular cross-section of 10 mm inner height and 20 mm width. On both the sides of the mould, in a longitudinal section two metal plates were mounted as lateral limitations that projected 2 mm beyond the upper edge of the triangular cross-section. The mould was dropped thrice from a height of 2 cm onto a solid surface. The mould was filled up with the test item again. The lateral limitations were then removed and the excess test item was scraped off. A non-combustible, non-porous and low heat-conducting base plate (ceramic tile) was placed on top of the mould and the apparatus was inverted and the mould was removed. A hot flame from the gas burner (diameter of the burner, 25 mm) was applied to one end of the powder train for a period of two minutes (maximum period). But it was observed that the test item powder train ignited after 2 seconds of application of the hot flame from the gas burner but the test item failed to burn the specified distance of 200 mm and just a linear, gentle (non-vigorous) combustion along the powder train was observed up to 12 cm within four minutes of total testing period after the withdrawal of flame (flame withdrawn after 2 minutes).

Also there was no smoldering observed up to a distance 200 mm within 4 minutes of total testing period after the withdrawal of flame.

Applicant's summary and conclusion

Interpretation of results:

not classified based on GHS criteria

Conclusions:

Tungsten disilicide is not flammable.

Executive summary:

In the 'Preliminary Screening Test', ignition of the test item powder train was observed after 2 seconds of application of the hot flame from the gas burner but the test item failed to burn the specified distance of 200 mm and a linear, gentle (non-vigorous) combustion along the powder train was observed only up to 12 cm within 4 minutes of total testing period after the withdrawal of flame (flame withdrawn after 2 minutes). Also there was no smoldering observed up to a distance 200 mm within four minutes of total testing period after the withdrawal of flame.

Although the test item powder-train readily ignited, it failed to burn the entire specified distance of 200 mm along the powder train and moreover, as there was no smouldering observed up to the specified distance of 200 mm along the powder train within 4 minutes of total testing period after the withdrawal of flame, tungsten disilicide is considered to be not flammable.