Registration Dossier

Environmental fate & pathways

Henry's Law constant

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

From the water surface, the substance will not evaporate into the atmosphere. The calculated Henry's law constant of maleic acid of 0.1E-5 atm-m³/mole suggests that the substance will not evaporate from water surfaces to the air.

Key value for chemical safety assessment

Henry's law constant (H) (in Pa m³/mol):
0
at the temperature of:
25 °C

Additional information

The Henry's law constant calculated for maleic acid of 0.000001 Pa*m³/mol indicates that maleic acid will not evaporate from water substances (SRC HENRYWIN v3.20, BASF 2009). The calculated Henry's law constant of maleic anhydride of 1.141E-11 atm-m³/mole suggests that the substance will not evaporate from water surfaces to the air (SRC HENRYWIN v3.10, 2009). However, since the substance rapidly hydrolyses in contact with water forming maleic acid, the product of hydrolysis should be considered when evaluating the fugacity of the substance.

Maleic acid and maleic anhydride are readily biodegraded under aerobic conditions in sewage sludge, and are expected to biodegrade in soil and water as well. Fugacity-based fate and transport modelling suggest that maleic anhydride, hydrolyzed to maleic acid in water and under humid conditions, will partition primarily to water. Level III fugacity modelling indicates water as the primary compartment for distribution (air 0.3%, water 59%, soil 40.6%, sediment 0.02%) (OECD, 2004).