Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Reaction mass of 2-(3,4-dimethyl-1H-pyrazol-1-yl)succinic acid and 2-(4,5-dimethyl-1H-pyrazol-1-yl)succinic acid is characterized by a high water solubility of 15.7 g/L (OECD 105), a vapour pressure of 0.002 Pa at 25 °C (OECD 104) and a log Koc of 0.6 - 2.1 (OECD 106).Since the substance is used as a nitrification inhibitor for agricultural crops, its target compartment will be the terrestrial compartment. Due to its high solubility in water and low adsorption potential, it is expected to mainly partition into the soil pore water.

Hydrolysis is not considered to be a relevant degradation pathway since the substance does not contain any chemical groups allowing hydrolysis in contact with water. The substance is considered to be hydrolytically stable in the environment. Significant biodegradation by activated sludge microorganisms is not expected. 0% degradation was recorded in a standard biodegradation study according to OECD 301A. Thus, the substance is not readily biodegradable according to the OECD criteria. Since the main compartment for environmental distribution is the soil, the degradation in soil was further investigated in a study according to OECD 307. A rapid degradation to 3,4-dimethylpyrazole (DMP) with normalized half-lives of 1.5 - 3.3 d was demonstrated. Degradation of DMP was tested in parallel and normalized half-lives of 3.8 - 8.9 d of the substance in soil were determined. Thus, the parent substance and its metabolite degrade rapidly in the soil compartment. Bioaccumulation of the substance is expected to be low based on the low log Pow of < -2.2.