Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Biodegradation in water: screening tests

The half life period of Eicosanoic acid in water is 15 days and based on this value it can be concluded that the chemical is not persistent in water medium since the half life is less than the threshold of 60 days (to qualify the chemical as persistent). Also the diffusion percentage of Eicosanoic acid in water medium is 24%.This coupled with the dilution of water shall result in ready biodegradabililty of the chemical.

PBT Profiler Database

Media

Half-Life (days)

Percent in
Each Medium

Water

15

  24%

Fugacity Model by EPI Suite estimation database

 

Mass Amount (percent)

Half-Life (hr)

Emissions (kg/hr)

Water

24.5

360

1000

 

Fugacity (atm)

Reaction (kg/hr)

Advection (kg/hr)

Reaction (percent)

Advection (percent)

Water

8.16e-012

658

342

21.9

11.4

Biodegradation in water and sediment: simulation tests

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%

Biodegradation in soil

The PBT Profiler & EPI Suite has estimated that Eicosanoic acid is expected to be found predominantly in soil and its persistence estimate is based on its availability in this medium. Its half-life in soil, 30 days (720 hrs).,does not exceeds the threshold of 120 days as per Annex XIII of REACH.Therefore, Eicosanoic acid is estimated to be not persistent in the soil environment.

PBT Profiler Estimate

Media

Half-Life (days)

Percent in
Medium

Soil

30

74%

Fugacity Model by EPI Suite estimation database

 

Mass Amount (percent)

Half-Life (hr)

Emissions (kg/hr)

Soil

74.3

720

1000

 

Fugacity (atm)

Reaction (kg/hr)

Advection (kg/hr)

Reaction (percent)

Advection (percent)

Soil

2.91e-011

999

0

33.3

0