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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Nonylphenol has a low water solubility (6 mg/l at 20 °C) and available data (including Henry Law Constant: 11.02 Pa m³/mol) indicates that volatilization of nonylphenol is likely to be low to medium removal process from water.

The Key study for the adsorption endpoint is the highly reliable study by Milinovic et al (2015) using five field-collected soils reported the Kd (Log Kd) for nonylphenol ranged from 24 to 1,059 ml g-1(1.4 to 3.0) and a Koc value of 11,060, with a strong relationship indicated between the soil organic carbon and adsorption. Desorption experiments showed nonylphenol was irreversibly sorbed onto the soils, demonstrating the significant potential for adsorption of nonylphenol to soils. An array of different approaches have been considered to determine the predicted adsorption of nonylphenol to sludge within WWTP. This has included experimentally derived Koc and Kd values, modelled Koc and Kd values, and the application of those values into two different modelling approaches - SimpleTreat and based on equations detailed in the OECD 106 guidelines. All results indicate that nonylphenol will be strongly adsorbed to sewage and sewage treatment plant solids similarly to the absorption onto soil and sediment in the environment.  

Nonylphenol tends to adsorb strongly onto organic matter. Adsorption is likely to play an important role as a sequestration process in soil, sediment, and sewage sludge. Adsorption to solids such as sediments and sewage sludge is likely an important removal process for nonylphenol. Adsorption to sewage sludge enables removal of nonylphenol prior to entering aquatic environments.