Phorate Degrades in Water (Highly Toxic)

Hydrolysis of Phorate Using Simulated Environmental Conditions: Rates, Mechanisms, and Product Analysis

Feng Hong and Simo Pehkonen*

Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0071

Partial funding for this research is provided by the University of Cincinnati Research Council.


The hydrolysis of phorate, an organophosphorus pesticide, was studied under simulated environmental conditions. Several metal oxides (aluminum hydroxide, hematite, goethite, and ferrihydrite) were chosen to represent the solid phase in natural aquatic systems.

Several degradation products were identified using GC-MS in combination with wet chemistry methods. Microtox was used to measure the toxicity of phorate and one of the degradation products, diethyl disulfide.

Two potential reaction pathways were proposed for the alkaline hydrolysis of phorate that results in unusual products, such as formaldehyde and diethyl disulfide.

No statistically significant catalytic effect was observed for the four metal (hydr)oxides used in the study. However, diethyl disulfide was found to be highly toxic (EC50 is 2.0 ppm).

This study again confirmed the need for the study of the environmental impact of the degradation products of pesticides.

J. Agric. Food Chem., 46 (3), 1192 -1199, 1998. Copyright 1998 American Chemical Society

Remember we are NOT Doctors and have NO medical training.

This site is like an Encyclopedia - there are many pages, many links on many topics.

Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.