Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability

Phototransformation in air

Stability of the substance in the atmosphere was calculated using the computer program AOPWIN (v 1.92). It is predicted that the substance will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals. The half-life for this reaction in air is estimated to be approximately 13 hours

Hydrolysis

In accordance with REACH Regulation 1907/2006, Annex VIII, Column 2 hydrolysis as a function of pH does not need to be determined as the substance can be regarded as readily biodegradable.

Stability of the substance against hydrolysis was calculated using the computer program HYDROWIN (v 2.00).A base-catalysed second-order hydrolysis rate constant of 0.03486 L/(mol-sec) at 25 deg C was estimated using a structure estimation method. This corresponds to half-lives of 6.3 years at pH 7 and 230.2 days at pH 8.

 

Biodegradation

Ready biodegradability has been determined with a non adapted activated sludge in the Modified Sturm test. The substance reached the 10% level (beginning of biodegradation) after 9 days. The test item did not reach the 60% pass level within the 10-day-window, but after 24 days. The substance is regarded, as a minimum, as inherently biodegradable and can be regarded as readily biodegradable though failing the 10 -day window criterium.

With adapted sludge, primary degradation in excess of 99% occurred over 28 days and ultimate degradation, measured as CO2 evolution, was 76% after 28 days.

In accordance with REACH Regulation 1907/2006/EC (Annex IX - 9.2.1.2, 9.2.1.3, 9.2.1.4 - column 2) simulation tests of biodegradation in water, sediment and soil do not need to be conducted.

 

Bioaccumulation

BCF has been calculated using the computer program BCFBAF (v3.01). It is predicted that the substance has a BCF of 153 L/kg wet weight.

 

Transport and distribution

Adsorption / desorption

The adsorption coefficient (Koc) on soil and on sewage sludge using high performance liquid chromatography (HPLC) has been estimated andadsorption coefficients estimated to be log Koc,soil = 21.41 and log Koc, sewage sludge = 23.21. These values correspond to a Koc,soil = 2.582E21 and Koc,sewage sludge = 1.642E23. The McCall classification scheme classifies the substance as immobile in soil (Koc > 5000).

Henry's Law constant

The Henry's Law constant was estimated using the software HENRYWIN (v3.20). The value of 6.69 Pa m³/mol indicates that the substance is moderately volatile from surface water.

Distribution modelling

Distribution in environmental compartments was calculated using a Fugacity model according to Mackay, Level III. Distribution in various environmental compartments is estimated as: Air - 0.413%; Water - 3.5%; Soil - 27.2% and Sediment - 68.9%.

Sediment and soil are therefore considered to be the major target compartments.