The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.


Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996


Trade and Other Names: Fenthion was formerly called DMTP. Trade names include Bay 29493, Baycid, Baytex, Dalf, DMTP, Entex, Lebaycid, Mercaptophos, Prentox Fenthion 4E, Queletox, S 1752, Spotton, Talodex, and Tiguvon.

Regulatory Status: Fenthion is a moderately toxic compound in EPA toxicity class II. It is classified by the U.S. Environmental Protection Agency (EPA) as a Restricted Use Pesticide (RUP) due to the special handling warranted by its toxicity. All bird control products, as well as nondomestic, nongranular formulations of 70% and greater are RUPs. RUPs may be purchased and used only by trained certified applicators. Fenthion may not be used on food crops. Labels for products containing fenthion must bear the Signal Word WARNING.

Chemical Class: organophosphate

Introduction: Fenthion is a contact and stomach organophosphate insecticide used against many sucking, biting pests, especially fruit flies, stem borers, mosquitoes, and Eurygaster cereal bugs. In mosquitoes, it is toxic to both the adult and immature forms (larvae). Once used extensively in the U.S. for controlling intestinal worms, fenthion no longer has FDA approval due to poisoning deaths. Fenthion is available in dust, emulsifiable concentrate, granular, liquid concentrate, spray concentrate, ULV, and wettable powder formulations. While it is effective as an insecticide, it is also moderately toxic to mammals, and highly toxic to birds. Based on its high toxicity to birds, fenthion is used in various parts of the world for weaver bird control. Pest control operators have used it to control pigeons around public buildings, as well. For bird control, use is made of fenthion's contact action and its ready absorption through the skin. It is applied as a paste to roosting areas when utilized for such purposes.

Formulation: Fenthion is available in dust, emulsifiable concentrate, granular, liquid concentrate, spray concentrate, ULV, and wettable powder formulations.

Toxicological Effects:

Ecological Effects:

Environmental Fate:

Physical Properties:

Exposure Guidelines:

Basic Manufacturer:

Miles, Inc.
P.O. Box 4913
8400 Hawthorn Road
Kansas City, MO 64120


References for the information in this PIP can be found in Reference List Number 5

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.