Carbonyl difluoride

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Data source

Reference

Reference Type:

publication

Title:

Pyrolysis products of polytetrafluoroethylene and polyfluoroethylenepropylene with reference to inhalation toxicity

Author:

Arito H, and Soda R.

Year:

1977

Bibliographic source:

Ann. Occup. Hyg. 20:247-255

Materials and methods

Principles of method if other than guideline:

- Principle of test: analysis of the pyrolysis products of polytetraflyoroethylene (PTFE) or polyfluoroethylepropylene (PFEP)
- Short description of test conditions: polytetraflyoroethylene or polyfluoroethylepropylene were submitted to high temperatures, in dry air stream, dry nitrogene, wet air and wet nitrogen streams
- Parameters analysed / observed: analysis of the pyrolysis products (qualitative)

GLP compliance:

no

Remarks:

Prior to GLP standards

Results and discussion

Any other information on results incl. tables

Pyrolysis in the nitrogen stream (dry or humid)

- PTFE at 500 -650°C: main products identified were tetrafluoroethylene, hexafluoropropylene, octafluorocyclobutane

- PTFE at 450°C: main products were tetrafluoroethylene, hexafluoropropylene

- PFEP at 400°C: main products were tetrafluoroethylene, hexafluoropropylene

Pyrolysis in the air stream:

Carbonyl fluoride was a main pyrolysis product of PTFE in dry air stream.

Other bands appeared in the IR spectra, corresponding to carbon tetrafluoride, hexafluoroethane, and silicon tetrafluoride.

Trifluoroacetylfluoride was identified in the pyrolysis products of PTFE and PFEP in the air stream.

With both compounds, in the humid air stream, CO2 was of greater intensity in IR spectra, while carbonyl fluoride decreased significantly at 550°C and disappeared at 500°C. Acidic droplets present in the wet air stream were analysed following precipitation and identified as trifluoroacetyl fluoride.

The results support the following reaction of pyrolysis products containing COF2 and trifluoroacetyl fluoride with the humid air:

COF2 + H2O ----> CO2 + 2HF

CF3COF + H2O ---> CF3COOH + HF

Applicant's summary and conclusion

Conclusions:

Analysis of pyrolysis products from PTFE and PFEP under various conditions showed that carbonyl fluoride was one of the main pyrolysis products in oxidative pyrolysis. In the presence of humid air, increase in carbon dioxide and decrease in carbonyl fluoride indicated reaction of carbonyl fluoride with water to form CO2 and hydrogen fluoride.