Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

- Abiotic degradation:

Air: Based on estimation with the QSAR model Aopwin (using the Smiles notation: N#CC(CCCC)c1ccccc), Salicynalva

undergoes in air rapid degradation after reaction with hydroxyl radicals. The degradation with ozone could not be calculated. The DT50 value after reaction with hydroxyl radicals is 13.9 hours. The half-life time of the substance is < 2 days. The substance will not reach the stratosphere and is therefore not considered to be a long-range transported chemical in air (http://www.unece.org/fileadmin/DAM/env/documents/2000/ece/eb/ece%20eb%20air.60.e.pdf).

The substance does not have an ozone depletion potential because it does not contain halogens and does not have the potential to reach the stratosphere (CLP, 2008, Part 5).

Water: The half-life of the substance in water is at pH 4, 7 and 9 at 25.9, 15.4 and 4.7 days according to OECD TG 111. This study shows that under environmental conditions some hydrolysis will occur.

- Biotic degradation:

In a screening study according to OECD TG 301D 0% biodegradation was found after 28 days. This study shows that the substance is not readily biodegradable under the conditions of this test. In a simulation test according to OECD TG 303 circa 90% primary /ultimate degradation was observed after circa 55 days including 25 days of equilibration period and with continuous feed of the test substance. For the risk characterisation the results of the first test will be used because the non-ready biodegradability of Salicynalva is based on its mineralisation, while in the simulation test it is difficult to distinguish between primary degradation and ultimate degradation.

 - Bioaccumulation:

The BCF in aquatic organism was estimated to be 93.1 with the equation of Veith (1979) using a log Kow of 3.14. It can be concluded that the substance has a low bioaccumulation potential.

The BCF in earthworms was estimated to be 17.4 l/kg ww with the equation from Jager (1998), indicating that the potential for bioaccumulation in terrestrial organisms will also be low.

 - Transport and distribution:

The substance is a moderately lipophilic substance with log Kow 3.14. The sorption to organic matter has been determined experimentally and is 437. This indicates that the substance will have a low potential to adsorb to sediment/soil.

To assess the volatilisation potential of the substance a Henry's law constant was calculated which gave a result of 27.4 at 25°C and 13.1 Pa.m3/mol at environmental temperature (12oC). From the distribution modelling results it can be concluded that volatilisation is of some importance 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 Smiles notation: N#CC(CCCC)c1ccccc1 and the measured physico-chemical parameters as input, it is estimated that the majority of the substance released to the environment will partition mainly into soil (73%) and water (24%) with small amounts to sediment and air (1 and 2%, respectively).

The SimpleTreat model, which is incorporated in EUSES, simulated the distribution of the substance in a Sewage Treatment Plant based on vapour pressure, water solubility, log Kow and biodegradability. The model predicts that 77.3% of the substance will partition to water, 4.9% to sewage sludge and 17.7% to air at 12°C.