Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Abiotic degradation


Air: No experimental data on the phototransformation of the substance in air are available. Based on estimation with the QSAR model AopWin the substance undergoes in air rapid degradation after reaction with hydroxyl radicals or ozone. The DT50 values after reaction with hydroxyl radicals are 1.081 hours for the cis-isomer and 1.022 hours for the trans-isomer, respectively. The DT50 values after reaction with ozone are 1.337 hours for the cis-isomer and 1.301 hours for the trans-isomer. These values are not used in the risk characterisation because these are not experimental values. These estimated half-life times are much shorter than 2 days, which is the cut off time for reaching the stratosphere. The substance is therefore not expected to reach the stratosphere and is not a long-range transported chemical in air (EU CLP, EC no 1272/2008 and its amendments).


Water: Based on a study performed on the substance the half-life time at 25°C is >1 year at pH 4, 332 days at pH 7 and 41 days at pH 9. It is concluded that the substance is hydrolytically stable under environmental conditions.


 


Biotic degradation


In a screening study according to OECD TG 301C, 16% biodegradation was found after 28 days. This study shows that the substance is not readily biodegradable.


 


Bioaccumulation


The BCF value aquatic organisms was determined experimentally as 58.3 L/kg in a study according to OECD TG 305. The BCF value for terrestrial organisms was calculated to be 191 L/kg. It can be concluded that the substance has a limited bioaccumulation potential.


 


Transport and distribution


The adsorption coefficient (Koc) of the substance has been determined to be 1259 L/kg, log Koc of 3.1, using the HPLC screening method (OECD TG 121). This indicates that the substance will have moderate potential to adsorb to sediment/soil.


 


A Henry's law constant was calculated which showed a value of 3.47 Pa. m3/mol at 12°C. This means that volatilisation will only play a minor role in the environmental behaviour of the substance. 


 


Based on Level III distribution modelling using EPISUITE (assuming equal and continuous releases to air, water and soil) using the CAS number 57378-68-4, the measured water solubility and Kow value as input, it is estimated that the majority of the substance released to the environment will partition mainly into soil (83.9%) and water (15.0%) with small amounts to sediment and air (1.05% and 0.05%, respectively).  


 


The SimpleTreat model, which is incorporated in EUSES, simulates the distribution of the substance in a Sewage Treatment Plant based on vapour pressure, water solubility, log Kow and non-ready biodegradability. The model predicts that 82.3% of the substance will partition to water, 13.3% will partition to sewage sludge and 4.38% to air.

Additional information