Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Though not readily biodegradable, PFBE (3,3,4,4,5,5,6,6,6-nonafluorohexene) is not likely to persist in surface waters due to its low water solubility (15.6 mg/l), high vapour pressure (22kPa at 20°C) and estimated Henry's Law constant (3 - 100 atm.m3.mol-1). As a result, any releases of PFBE to the aquatic environment are likely to rapidly partition to atmosphere, and detectible concentrations will be hard to acheive. PFBE has only moderate affinity for soil (measured log Koc = 2.96 Koc = 903). Volatilisation from wet and dry soil surfaces would be an important fate process for any releases, based on the estimated Henry's law constant and this compound's high vapour pressure. Consequently, any PFBE released into the environment is expected to partition almost entirely to the atmosphere, where it will quickly react with atmospheric hydoxyl radicals (°OH), with a short atmospheric lifetime, estimated to be 6.4 hours.

Direct and indirect exposure of the aquatic compartment, sediment and soil by PFBE is considered unlikely. (See attached report PFBE: REACH Annex IX waivers for Degradation and Fate and Behaviour in the Environment. Blue Frog Scientific Limited.)