Registration Dossier

Administrative data

Endpoint:
phototransformation in air
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented publication which meets basic scientific principles.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2008

Materials and methods

Test guideline
Qualifier:
no guideline required
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
gas under pressure: liquefied gas

Study design

Details on test conditions:
FTIR–smog chamber system at Ford:
Experiments were performed in a 140-l Pyrex reactor interfaced to a Mattson Sirus 100 FTIR spectrometer. The reactor was surrounded by 22 fluorescent blacklamps (GE F15T8-BL) which were used to photochemically initiate the experiments. CH3ONO was synthesized by the drop wise addition of concentrated sulfuric acid to a saturated solution of NaNO2 in methanol. O3 was produced from O2 via silent electrical discharge using a commercial O3 ozonizer. Samples of t-CF3CH=CHCl were supplied by Honeywell International Inc. at purities >99.9%. All other reagents were obtained from commercial sources at purities >99%.
Relative rate and absolute rate experimental methods were used as described above. Experiments were conducted in 700 Torr total pressure of air/N2 diluent at 295±2 K. The loss of t-CF3CH=CHCl and reference compounds was monitored by FTIR spectroscopy using a calibrated analytical path length of 27.1 m and a spectral resolution of 0.25 cm−1. A liquid nitrogen cooled midband MCT detector was used in this study. Infrared spectra were derived from 32 coadded interferograms. Reactant and reference compounds were monitored using absorption features over the following wavenumber ranges (cm−1): C2H2, 650–800; C2H4, 900–1000; O3, 980–1070; t-CF3CH=CHCl, 669, 847, 935, 1311, and 1648.

FTIR–smog chamber system at University of Copenhagen:
The Copenhagen experiments were performed in a 100-l quartz reactor equipped with a Bruker IFS 66V FTIR spectrometer. The experimental setup was equipped with a temperature control system that kept the temperature steady at 293±0.5 K. An InSb detector was chosen for this study. Chlorine atoms were produced by photolysis of Cl2 according to reaction (Cl2 + hv → Cl + Cl), using UVA lamps (Osram Eversun L100/79) with the main emissions peak at 368 nm. Ozone was produced using a commercially available ozone generator from O3-Technology. The ozone was preconcentrated using a silica gel trap, reducing the amount of O2 introduced into the chamber. Samples of t-CF3CH=CHCl were supplied by Honeywell International Inc. at purities >99.9%. All other reagents were obtained from commercial sources at purities >99%.
Relative rate and absolute rate experimental methods were used as described above. The Cl atom relative rate experiments were conducted in 700 Torr total pressure of N2 diluent. Ozone kinetics experiments were conducted in 700 Torr total pressure of air diluent. The White-type optical system propagating the IR beam through the reaction chamber had a path length of 86 m. Spectra were obtained at a resolution of 0.115 cm−1 and were derived from 64 coadded interferograms. Reactant and reference compounds were monitored using absorption over the following wavenumber ranges (cm−1): C2H2, 3175–3375; C2H4, 2940–3040; O3, 2950–3065; t-CF3CH=CHCl, 3060–3130. FTIR spectra were analyzed using a linear least squares fitting procedure developed by Griffith. Reference spectra of O3 and HCl were taken from the HITRAN database, and used to improve the spectral fitting for the larger molecules. For the other components, reference spectrawere recorded using the same conditions (700 Torr, 293±0.5 K) employed in the kinetics experiments.

Results and discussion

Dissipation half-life of parent compound
DT50:
26 d
Degradation rate constantopen allclose all
Reaction with:
OH radicals
Rate constant:
0 cm³ molecule-1 s-1
Reaction with:
ozone
Rate constant:
0 cm³ molecule-1 s-1

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
The atmospheric lifetime of t-CF3CH CHCl is determined by reaction with OH radicals and is approximately 26 days.
Executive summary:

Long path length Fourier transform infrared (FTIR)–smog chamber techniques were used to study the kinetics of the gas-phase reactions of Cl atoms, OH radicals and O3 with trans-3,3,3-trifluoro-1-chloropropene, t-CF3CH=CHCl, in 700 Torr total pressure at 295±2 K. Values of k(Cl + t-CF3CH=CHCl) = (5.22±0.72)×10−11 cm3 molecule−1 s−1, k(OH + t-CF3CH=CHCl) = (4.40±0.38)×10−13 cm3 molecule−1 s−1 and k(O3 + t-CF3CH CHCl) = (1.46±0.12)×10−21 cm3 molecule−1 s−1, were established (quoted uncertainties are 2σ). The IR spectrum of t-CF3CH=CHCl is reported. The atmospheric lifetime of t-CF3CH=CHCl is determined by reaction with OH radicals and is approximately 26 days. The global warming potential of t-CF3CH=CHCl is approximately 7 for a 100-year time horizon.