Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Releases of PPVE are anticipated to be primarily to the atmospheric compartment. This compound is unlikely to partition to terrestrial or aquatic compartments from the atmosphere based on partition coefficients (see below).

The experimental vapor pressure (410 mm Hg at 20 °C) and Henry’s Law constant (3200 dimensionless, or 78.3 atm∙m³/mol, at 22.6 °C) suggest that PPVE will partition from wet or dry terrestrial surfaces into the atmosphere. Henry's Law constant (HLC) is used to describe the tendency for a substance to partition from water to air, the higher the value the greater the tendency for partitioning from water to air. For PPVE, the measured HLC indicates that it is likely to volatilize from the aquatic compartment into the atmosphere. Only negligible amounts of PPVE are expected to be present in aquatic systems or soils.

The logarithm of the organic carbon normalized adsorption coefficient (log Koc) is used to describe the tendency for a substance to partition from water to soils or suspended solids. The log Koc could not be measured but was calculated¹ to be 3.34 based on the measured log Kow value (i.e., 4.0 at 21.9 °C). Given the rapid partitioning to the atmosphere from soils and from water, the overall net partitioning of PPVE will be to the atmosphere.

The logarithm of the octanol air partition (log Koa) coefficient is used to describe the tendency of a substance to partition from air into the lipid rich tissues of air breathing organisms. The calculated log Koa of PPVE is 0.46, based on the dimensionless Henry’s Law constant value at 22.6 °C and the average experimental Kow value (that is, the untransformed average of concentration ratios) of 9150 at 21.9 °C. This log Koa value indicates that PPVE has a low potential to partition from air to the lipid rich tissues of air-breathing organisms.

(1) European Chemicals Bureau: Technical Guidance Document of Risk Assessment, Chapter 4.