Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Photodegradation:

Concerning environmental fate and pathways, a QSAR model was utilized to fulfill or support the different endpoints, which are mandatory under REACH. The scientifically accepted calculation tool EPIWIN (by US-EPA) was used to determine the phototransformation behavior in air, the biodegradation potential in water, aquatic bioaccumulation, soil adsorption and the substance specific Henry´s Law Constant (HLC).

AOPWIN v1.92 differentiates between the cis- and trans- isomer of the substance, resulting in an overall OH constant at 25 °C of 52.69E-12 cm³/molecule-sec and 59.53E-12 cm³/molecule-sec, respectively (Chemservice S.A., 2012). The half-lives are predicted as 2.44 hours for the cis-isomer and 2.16 hours for the trans-isomer, assuming a 12 hour light day and an OH rate of 1.5E6/cm³.

Hydrolysis:

The test substance was found to be hydrolytically stable at pH 4, 7 and 9 (Tarran, 2012). The experiment was conducted in the dark at a temperature range of 50 +/- 0.5 °C and according to the conditions of OECD Guideline 111. The half-life will >1 year at each pH value, respectively. As less than 10 % hydrolysis occurred after five days, no further testing to determine the rate constants was performed.

Biodegradation:

The biodegradability of the test substance was investigated experimentally in accordance to EU Method C.4-D (Kanne, 1993). After 28 days, the test substance attained 81 % degradation, hence the test substance is considered as "readily biodegradable" (key study).

Additionally, experimental results are available concerning biodegradation, published by Brorson et al. (1994) characterizing the "ultimate" aerobic biodegradability according to ISO 7927. The test substance attained 68 % degradation after 28 days using bentonite as carrier.

In a QSAR prediction with BIOWIN v4.10 the test substance is considered as "not readily biodegradable" (Chemservice S.A., 2011). However, since the Ultimate and Primary Biodegradation Timeframe is given in weeks / days-weeks, the substance is not considered as persistent.

Bioaccumulation:

The aquatic bioconcentration factor (BCF) was predicted as 10.8 L/kg wet-wt by the regression-based estimate of BCFBAF v3.01 (Chemservice GmbH, 2011). The bioconcentration factor was detected as <1.7 and <18 concerning a substance concentration of 100 µg/L and 10 µg/L, respectively. Based on these results, the bioaccumulation potential of the substance is very low.

Soil Sorption:

A low potential for soil adsorption is predicted by KOCWIN v2.00, since the organic-normalized sorption coefficient (Koc) was predicted as 184.4 L/kg (Chemservice S.A., 2012).