Exposure phase
Ecotoxicology - Assessment of the properties of chemical substances

Many phenomena tend to transform substances in the environment:

• hydrolysis;

• biodegradation ;

• photolysis;

• decomposition ;

• oxidation.

Direct or indirect photodegradation by sunlight is the main process by which substances disappear into the atmosphere. Photolysis essentially involves radical reactions that lead to the transformation or disappearance of the substance in the atmosphere.

In the aquatic environment, the main degradation processes for chemical substances are hydrolysis and biodegradation. Hydrolysis is characterized by a half-life in water, which can be determined by standardized tests such as the OECD 111 pH-dependent hydrolysis...