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Administrative data

Link to relevant study record(s)

Description of key information

Half life period of Eicosanoic acid in water is observed to be 15 days (360 hrs.) while in sediment it is 140 days (3360 hrs.).Based on these half life values of Eicosanoic acid, it is concluded that the chemical is readily biodegradable in water where as it is non biodegradable in sediment. However, since there is no diffusion of the substance in the sediment medium as evident from the reported data (0%) and hence persistence in the sediment compartment is not likely to be critical.

Key value for chemical safety assessment

Half-life in water:
15 d
at the temperature of:
25 °C
Half-life in sediment:
140 d
at the temperature of:
25 °C

Additional information

Based on the Level III Fugacity Model, the half life period of the Eicosanoic acid was estimated. The half life period of Eicosanoic acid in water is 15 days (360 hrs) therefore it is considered that the substance will qualify as not persistent as the half life does not exceed the threshold of 60 days. So, it can be confirmed that the substance is readily biodegradable in water medium where as in sediment the half life is 140 days (3360 hrs).

Based on this value, it can be inferred that the substance is persistent in sediment medium and is not readily biodegradable probably due to the anaerobic conditions existing in most sediments.However, it can be observed that  there is no diffusion of the substance in the sediment medium as evident from the reported data (0%) and hence persistence in the sediment compartment is not likely to be critical.

Media

Half-Life
(days)

Percent in
Each Medium

Water

15

24%

Sediment

140

0%