Assessing the potential climate impact of anaesthetic gases.

There is increasing concern within the health-care community about the role care delivery plays in environmental degradation, sparking research into how to reduce pollution from clinical practice. Inhaled anaesthetics is a particular research area of interest for two reasons. First, several gases are potent greenhouse gases, and waste gas is mostly emitted directly to the environment. Second, there are options to reduce gas waste and substitute medications and procedures with fewer embodied emissions while delivering high-quality care. Performance improvements are contingent on a proper understanding of the emission estimates and climate metrics used to ensure consistent application in guiding mitigation strategies and accounting at various scales. We review the current literature on the environmental impact and the estimation of the potential climate forcing of common inhaled anaesthetic drugs: desflurane, sevoflurane, isoflurane, methoxyflurane, and nitrous oxide.

Atmospheric chemistry of CF3CN: kinetics and products of reaction with OH radicals, Cl atoms and O3.

Long path length FTIR-smog chamber techniques were used to study the title reactions in 700 Torr of N2, oxygen or air diluent at 296 ± 2 K. Values of k(Cl + CF3CN) = (2.43 ± 0.33) × 10-15 and k(OH + CF3CN) = (4.61 ± 0.34) × 10-15 cm3 molecule-1 s-1 were measured. There was no discernible reaction of CF3CN with O3 and an upper limit of k(O3 + CF3CN) ≤ 7.9 × 10-24 cm3 molecule-1 s-1 was established. The IR spectra of CF3CN and CF3CF2CN are reported. The atmospheric lifetime of CF3CN is determined by the reaction with OH and is approximately 6.9 years. Reaction of CF3CN with Cl atoms in a chamber study gives (Z-) and/or (E-) CF3CClNCl and CF3C(O)Cl as major primary products. Under environmental conditions, the OH radical initiated oxidation gives COF2 in a yield of (96 ± 8)%. The global warming potential for CF3CN is estimated as 1030 for a 100 year time horizon.

Atmospheric chemistry of a cyclic hydro-fluoro-carbon: kinetics and mechanisms of gas-phase reactions of 1-trifluoromethyl-1,2,2-trifluorocyclobutane with Cl atoms, OH radicals, and O3.

Long path length FTIR-smog chamber techniques were used to study the title reactions in 700 Torr of N2 or air diluent at 296 ± 2 K. Values of k(Cl + 1-trifluoromethyl-1,2,2-trifluorocyclobutane (TFMTFCB)) = (1.16 ± 0.21) × 10-14 and k(OH + TFMTFCB) = (3.51 ± 0.88) × 10-14 cm3 molecule-1 s-1 were measured. No reactivity of TFMTFCB towards ozone was observed. The atmospheric lifetime of TFMTFCB is determined by the reaction with OH and is approximately 330 days. The chlorine initiated oxidation gives C(O)F2 and CF3C(O)F as the dominant products in yields of (92 ± 2)% and (89 ± 2)%, respectively. The OH radical initiated oxidation gives C(O)F2 and CF3C(O)F as the dominant products in yields of (91 ± 6)% and (84 ± 4)%, respectively. The GWP100 was calculated as 44. The atmospheric chemistry of the title compound, a cyclic halogenated alkane, is discussed in the context of other halogenated cyclo-alkanes.