Polyhaloalkene

Phototransformation in air

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Administrative data

Endpoint:

phototransformation in air

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The products of Cl and OH radical initiated oxidation of CF3CF=CH2 were studied in a 700 Torr of N2/O2 diluent at 296 +/- 1K.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Details on test material:

>99.9%
purity >99.9%
sample supplied by Honeywell

Study design

Light source:

other: fluorescent backlamps

Results and discussion

% Degradation

Key result

% Degr.:

ca. 100

Sampling time:

10 d

Any other information on results incl. tables

The OH initiated oxidation of CF₃CF=CH₂ gives CF₃C(O)F and HCHO in almost quantitative yields. CF₃C(O)F is removed from the atmosphere via hydrolysis that occurs at a time scale of about 10 days to give CF₃C(O)OH, just like 134a (CF₃CH₂F) does. The available data suggest that while CF₃C(O)OH is not a natural component of the freshwater environment, it is a natural component of the background oceanic environment, and any additional burden associated with CF₃CF=CH₂ oxidation will be of negligible environmental significance.

Similarly HC(O)H decomposes to H₂O and CO, the latter oxidizing to CO₂ in the atmosphere.

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The atmospheric decomposition of CF3CF=CH2 will have negligible environmental impact.

Executive summary:

The atmospheric lifetime of CF3CF=CH2, dictated by its reaction with OH radicals, is approximately 11 days. The major atmospheric oxidation product of CF3CF=CH2 is CF3C(O)F. The atmospheric fate of CF3C(O)F is hydrolysis which occurs. We show here that is the major atmospheric oxidation product of CF3CF=CH2. The atmospheric fate of CF3C(O)F is hydrolysis which occurs on a time scale of approximately 10 days to give CF3C(O)OH. While CF3C(O)OH is not a natural component of the freshwater environment, it is a natural component of the background oceanic environment, and any additional burden associated with CF3CF=CH2 oxidation will be of negligible environmental significance. We conclude that the products of the atmospheric oxidation of CF3CF=CH2 have negligible environmental impact.