Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no data: aquatic toxicity unlikely

Marine water

Hazard assessment conclusion:
no data: aquatic toxicity unlikely

STP

Hazard assessment conclusion:
no emission to STP expected

Sediment (freshwater)

Hazard assessment conclusion:
no exposure of sediment expected

Sediment (marine water)

Hazard assessment conclusion:
no exposure of sediment expected

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
no exposure of soil expected

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

PMVE is a volatile gas at ambient conditions with a boiling point in the range of -26 °C (Yaws, Carl L. ©2010 Knovel), in addition, in case of accidental emission, it is released only to air compartment as indicated from the EQC Fugacity III Model (v.1.0, The Canadian Centre for Environmental Modelling and Chemistry, May 2003). Moreover on the basis of its Henry's Law constant of 32,100 P m^3/mol (HENRYWIN v3.20, EPISUITE v1.00) that entails a not measurable vapour pressure (i. e. 10^5 Pa) and a limited solubility in water (the value of water solubility of 31.5 mg/l has been evaluated in a closed system with the atmosphere saturated of PMVE hence it represents an overestimation of the actual water solubility of PMVE in the natural system) PMVE is expected to primarily and rapidly partition to the atmosphere.

Hence, due to the gaseous nature of the substance, its partition to the atmosphere, its limited water solubility as well as the consequent difficulty to appropriately test PMVE and provide meaningful results, no experimental aquatic toxicity data are reported, consequentely PNECs for aquatic organisms have not been calculated.

PNECs for sediment (freshwater or marine) and soil can't be derived and are technically not feasible, as PMVE is expected to primarly and rapidly partition to the atmosphere as also discussed above.

PNEC for air are not calculated since PMVE is not considered to represent an hazard.

It has been shown that the atmospheric degradation of PMVE produces the same fluorinated radical species as formed during the degradation of HFCs. HFCs do not impact stratospheric ozone and the same conclusion applies to HFEs; PMVE has an ozone depletion potential of zero. A rate constant of k(OH + CF3OCFCF2) = (2.6 +/- 0.3) x 10^-12 cm3 molecule^-1 s^-1 at 296 K in 700 Torr of air and an atmospheric lifetime of CF3OCF=CF2 with respect to reaction with OH of 0.023 years (8 days) have been estimated. The global warming potential (GWP) was estimated using the radiative forcing, lifetime and molecular weight to be 1.20 x 10^-3 for a 20 year horizon and ca. 4.57 x 10^-4 for a 100 year time horizon. Hence the GWP of PMVE can be considered negligible (Mashino, M., 2000) (Mashino, M., 2000).

According to Zhuangjie et al, the atmospheric lifetime of PMVE is then estimated to be less than 5 days due to the OH attack, in addition the Global Warming Potential for the PMVE is predicted to be small (less than 0.01) due to the short atmospheric lifetime of this molecule. On the basis this it is not expect the use of PMVE to lead to any significant impact on climate (Li, Zhuangjie et al. 2000).

Conclusion on classification

Since PMVE is a gas at ambient conditions (used in sealed systems) and its water solubility is limited, it does not represent a hazard to aquatic life. For this reason, no aquatic toxicity testing has been conducted. ECOSAR predictions for aquatic toxicity are applied, however the ECOSAR results have not been considered in this assessment since the ECOSAR model cannot be considered reliable for this class of chemicals. It can be concluded that PMVE does not pose a toxicity risk to aquatic or terrestric organisms in the unlikely event of entering and remaining in these compartments water or soil long enough to potentially affect organisms at all.

Based on the above considerations the substance is neither classifiable for acute nor chronic aquatic toxicity according to CLP (EC No 1272/2008)