EPTC (herbicide)

S-Ethyl dipropylthiocarbamate is a selective herbicide used for preëmergent control of certain grasses and broadleaf weeds in Australia and the United States. It was introduced in 1957.
EPTC can be applied preëmergently or postemergently and its effectiveness does not depend on post-application rainfall. The herbicide takes effect quickly afterward. It is registered in every US state. It should be sprayed when the soil is well worked and dry, for good mixing and incorporation. It can be stored at temperatures as low as -50 °F.
It is not persistent in soil, having a half-life of about 6 days.

Use

EPTC is applied at 2 to 7.5 lbs/ac in the US, or 2.5-5 kg/ha in Australia, measured by active ingredient. It is usually sold as an emulsifiable concentrate, of 70% or greater concentration, or as granules.
In 2001, 277,000 lbs of EPTC was used in California.

Registrations

In the United States, EPTC is registered for use on alfalfa, almonds, beans, birdsfoot trefoil, clovers, lespedeza, sainfoin, citrus nursery stock and plantings, cotton, grass, fallow, pine seedlings, potatoes, safflower, sugar beets, sunflower, tomatoes and walnuts.
In Australia, EPTC is used on beans, potatoes, maize, sweet corn, safflower, rapeseed, sunflower, lucerne, duboisia, lotus, non-crop situations and grass.
The EU does not allow the use of EPTC.

Safety

The EPA says in a 1999 report that EPTC produced no developmental or reproductive toxicity, and there was no cause for concern. Nevertheless, the State of California OEHHA is concerned that EPTC could be developmentally toxic.

Tradenames

EPTC has been sold under the tradenames Alirox, Eradicane, Eptam, Genep, Niptan, Shortstop, Torbin and Witox. The long-running "Eptam" trademark is the Stauffer Chemical Company's.