Norflurane

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

supporting study

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Global ozone research and monitoring project, scientific assessment of stratospheric ozone.

Author:

WMO

Year:

1989

Bibliographic source:

Report 20, Volume II, Appendix: AFEAS Report. World Meteorological Association, Geneva, Switzerland.

Reference 2

Reference Type:

publication

Title:

Acid deposition in the United Kingdom 1986-1988.

Author:

UKRGAR

Year:

1990

Bibliographic source:

Third report of the United Kingdom Review Group on Acid Rain. United Kingdom Review Group on Acid Rain, Warren Spring Laboratory, Stevenage, UK.

Reference 3

Reference Type:

publication

Title:

Acid deposition: perspective in time and space.

Author:

Galloway JW

Year:

1995

Bibliographic source:

Water Air and Soil Pollution 85:15‑24.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Norflurane

EC Number:

212-377-0

EC Name:

Norflurane

Cas Number:

811-97-2

Molecular formula:

C2H2F4

IUPAC Name:

1,1,1,2-tetrafluoroethane

Applicant's summary and conclusion

Executive summary:

Contribution to acid rain and environmental burden of fluoride ion On the basis of 15% conversion of HFC-134a to TFA and HF, 85% conversion to HCOOH, CO2 and HF, and uniform scavenging of the acids thus produced into the global average rainfall of 5 x 1011 kt/y, the calculated resulting levels of fluoride and acidity are low compared with those arising from existing sources: Assuming steady state conditions with an atmospheric release and degradation rate of 100 kt HFC-134a/y (equal to the expected releases in the early part of this century):

F– production would be 66 kt/y, i.e. very small compared with the estimated atmospheric fluoride flux of 1,000-8,000 kt/y (WMO, 1989).

The contribution of HFC-134a to the F– concentration in rainwater would be 0.12 ppbw . This level should be compared with typical fluoride concentrations in "background" rainwater of around 10 ppbw, i.e. 100 times greater, and with levels of about 1 ppmw   (1 mg/l) used for the fluoridation of drinking water, i.e. 10,000 times greater (WMO, 1989).

The trifluoroacetic, formic and hydrofluoric acids formed from HFC-134a and scavenged in rainwater would represent an acidity of close to 4.46 x 109 mol H+/y, i.e. about 3,000 times less than the acidity arising from natural and anthropogenic emissions of SO2 and NOx (UKRGAR, 1990; Galloway, 1995). Thus the contribution of HFC-134a to acid rain would be negligible.