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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Melcer et al. (2007) conducted a literature review with regard to physical-chemical properties and environmental fate characteristics of alkylphenols and alkylphenol ethoxylates. The authors found that Octylphenol (OP) released to the atmosphere is likely to be degraded by photo-oxidation, with a half-life of approximately 6 hours, based on calculations using EPISuite v3.12 (U.S. Environmental Protection Agency (US EPA). (2000a) EPISuite. Estimation Program Interface (EPI) Suite Version 3.12. Washington, DC).

Photochemical transformation of Octylphenol in surface waters is also a significant route of abiotic degradation. From experiments conducted by Ahel et al. (1994) according to general accepted scientific standards, a half-life of 10-15 hours could be deduced for continuous clear sky, noon, summer sunlight conditions in the surface layer of natural waters. The photolysis rate in the deeper layers is strongly attenuated, being approximately 1.5 times slower at depths of 20-25 cm than at the surface.

Although sunlight photolysis rates of OP were found to be much slower than reported for some other alkylphenols (Faust and Hoigné, 1987, cited in Ahel et al., 1994), the results suggest that a significant portion (30 %) of these compounds could be photochemically degraded in the surface layer of natural waters within one day.

Hydrolysis is unlikely to be a dominant route of abiotic degradation for Octylphenol, because of the chemical structure and particularly the lack of susceptible functional groups.

This finding is supported by the UK Environmental Risk Assessment (ERA) Report 2005 on 4-tert-octylphenol which states that hydrolysis would not be expected in view of the chemical structure. In addition, based upon the stability of 4-tert-octylphenol during storage and lack of degradation in controls in biodegradation studies, the UK ERAR 2005 concludes that it is likely that abiotic degradation is a negligible removal process. Therefore, hydrolysis is believed to be a negligible removal process for 4-tert-octylphenol in the aquatic environment.


These findings indicate that photo-oxidation and photochemical transformation, in contrast to hydrolysis, can be important removal processes for 4-tert-Octylphenol released to water and air.