Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability

Hydrolysis:

In an OECD 111 study conducted to GLP, the solubility of methylene bis(dibutyldithiocarbamate) in the buffer solutions pH 4.0, pH 7.0 and pH 9.0 was very low. It was not possible to increase the solubility of the test substance with the use of different solubilizers (acetone, acetonitrile and ethanol). Peaks obtained, if any, were too small to allow quantification or even to follow a degradation curve.

According to the EEC Directive 92/69 Section C.7, the method is applicable only to water soluble substances. The test item shows no significant solubility in the different solvent systems. Therefore, no further testing could be performed on the substance at pH 4, pH 7 and pH 9. (RCC Ltd, 2007).

According to Column 2 of Annex VIII of the European Union (EU) Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulation (EC) No 1907/2006 a Hydrolysis study can be waivered if the substance is highly water insoluble. In an OECD 111 study it was not possible to increase the solubility (0.247 mg/l) of methylene bis(dibutyldithiocarbamate) with the use of different solvents, therefore, no hydrolysis result can be provided and further testing is waived.

Biodegradation

Biodegradation in water (screening):

Key study:

In an OECD TG 301B study, conducted to GLP, methylene bis(dibutyldithiocarbamate) attained 21% degradation after 28 days and therefore cannot be considered to be readily biodegradable (Safepharm Laboratories Limited, 2004).

Biodegradation in water and sediment:

Based on the use pattern of methylene bis(dibutyldithiocarbamate), intentional releases into the sediment compartment are not expected.  In accordance with Column 2 of Annex IX of the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) legislation, if direct and indirect exposure of sediment is unlikely, a biodegradation in water and sediment study does not need to be conducted, therefore the endpoint is being waived. According to the screening study, methylene bis(dibutyldithiocarbamate) is not considered readily biodegradable (Safepharm, 2004).

Biodegradation in soil:

Based on the use pattern of methylene bis(dibutyldithiocarbamate), intentional releases into the soil compartment are not expected.  In accordance with Column 2 of Annex IX of the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) legislation, if direct and indirect exposure of sediment is unlikely, a biodegradation in soil study does not need to be conducted, therefore the endpoint is being waived.

According to the screening study, methylene bis(dibutyldithiocarbamate) is not considered readily biodegradable (Safepharm, 2004).

Bioaccumulation

Bioaccumulation:

BCF was determined as 6.082 by EPIWIN BCFBAF version 3.01 using the Arnot-Gabos method. The predicted BCF value was based in part on the measured Log Pow of 8.42 at 35 ºC (EPIWIN, 2012).

Bioaccumulation is considered to occur primarily in the upper trophic levels as the water solubility is very low (0.248 mg/l at 20 ºC) and the Log Pow is very high (8.42 at 35 ºC). The Arnot-Gabos method was therefore selected as the key value.

Transport and distribution

Adsorption / desorption:

Key study:

In an OECD 121 study, conducted to GLP, the LogKoc of methylene bis(dibutyldithiocarbamate) is 7.18 (WIL Research Europe, 2012).