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Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

ENVIRONMENTAL FATE PROPERTIES

Summary of degradation

Abiotic degradation

No data on the hydrolysis of shale oil (heavy fraction) are available. Based on the properties of the test substance (it is a mixture of various different compounds, not chemically well defined with no main component, of low solubility) a hydrolysis study is technically not feasible.

Biotic degradation

In an inherent biodegradability study to the OECD 302C guideline, at the end of the 28-day exposure period, the mean extent of biodegradation of Shale Oil (middle fraction) was 22%. Thus, some compounds of the test item were biodegradable. However, the major part of the test item was not biodegraded within 28 days of test duration in this inherent biodegradability test. It is considered acceptable to read-across from the middle fraction of shale oil to the heavy fraction, on the basis that the fractions were shown to be compositionally similar from the analytical data available.

On the basis of the results of the study for the purpose of the risk assessment it has been concluded that Shale Oil (heavy fraction) is: inherently biodegradable, not fulfilling specific criteria.

Volatilisation

No data available.

Distribution modelling

No distribution modelling data exist.

Summary of environmental distribution

Data are not available to allow the distribution of Shale Oil (heavy fraction) within the environment to be modelled. In Section 1.3 the solubility of Shale Oil (heavy fraction) is reported as 0.1 g/L, the Log Pow as 3.9 and the vapour pressure as 0.8 kPa at 25°C. Based on these properties the substance would be expected to be primarily distributed between air and soil/sediments with a low association with water. 

Summary and discussion of bioaccumulation

Aquatic bioaccumulation

Shale oils are complex mixtures of various different compounds which are not chemically well defined with no main component. Therefore, the performance of a bioaccumulation study is not possible. Although the Log Kow of the substance is >3 it is susceptible to biodegradation and thus the risk of bioaccumulation is low. The BCF in fish calculated by EUSES 2.1 using the LogKow of 3.9 is 412, which further indicates a low risk of bioaccumulation. The available data are adequate for classification and labelling purposes and PBT assessment, so no further testing is required. Also direct and indirect exposure of the aquatic compartment is unlikely.

Terrestrial bioaccumulation

No data are available on terrestrial bioaccumulation. However, the bioaccumulation potential of the substance is predicted to be low. The risk of terrestrial bioaccumulation is therefore negligible

Secondary poisoning

Shale Oils (heavy fraction) present a low risk with regard to secondary poisoning due its low bioaccumulation potential.