Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

MV 31 is a perfluorinated alkyl vinyl ether. It is used as a monomer in fluoropolymer production, and as a raw material to make a processing aid for fluorochemical polymerization. In polymerization systems, fluorochemical monomer is generally recovered for reuse. Little release to the environment is expected. With a water solubility of 145 µg/L, a vapor pressure of 50 hPa at 20 °C and a Henry's Law constant of 19300 (i.e., 469 atm∙m³/mol), MV 31 is expected to partition exclusively to the atmospheric compartment if released to the environment. In an OECD301F (manometric respirometry) assay, no biodegradation was observed. MV 31 is not readily biodegradable, and no further testing is proposed. No studies of abiotic degradation are available for MV 31. We have proposed waiving of hydrolysis testing due to low water solubility (145 µg/L at 23 °C). MV 31 has a log Koc of 3.7. However, MV 31 is expected to partition exclusively to the atmospheric compartment if released to the environment. The n-Octanol/Water Partition Coefficient (log Kow) for MV 31 was measured to be 5.1 at 23°C. No tendency to bioaccumulate in aquatic organisms is expected due, again, to high volatility and low water solubility. No tendency to bioaccumulate in air breathing organisms is expected based on a log Koa of 0.81.

The atmospheric reactions of MV 31 have not been studied. As a perfluorinated alkyl vinyl ether, MV 31 is subject to rearrangement forming perfluorinated acid fluorides upon exposure to free radicals. The structure(s) of putative acid fluoride(s) has not been determined. An analogous substance, perfluoro(methyl vinyl ether), degrades to form HF, TFA, and oxalyl diflouride on reaction with hydroxyl radical in smog chamber (1). In general, Perfluoroacid fluorides are hydrolytically unstable and will form the corresponding perfluorocarboxylic acids, which will be removed from the atmospheric compartment during rainfall. Release of MV 31 to the environment is expected to result in deposition of stable fluorinated carboxylic acid(s) to the terrestrial and aquatic compartments.

1) M. Mashino, M. Kawasaki, T.J. Wallington, M.D. Hurley. 2000. Atmospheric Degradation of CF3OCF=CF2: kinetics and mechanism of its reaction with OH radicals and Cl atoms. J. Phys. Chem. Vol 104, pages 2925-2930.