Skip to main content

Eptam / EPTC

Chemical Structure

Chemical Name:

S-ethyl dipropyl carbamothioate.

Chemical Family:


WSSA Resistance Group:


Crop/non-crop registration:

Alfalfa, clover, bird'sfoot trefoil, beans, potatoes, sunflowers

Sensitive weeds:

Mostly annual grasses; yellow nutsedge; pigweed, lambsquarters, and nightshade if conditions are favorable for germination/growth.

Application method:

PPI - incorporate to 10 cm (4"); should be incorporated shortly after application to avoid volatilization and photodegradation losses, especially on moist soils.

Absorption & Translocation:

Readily absorbed by underground plant parts (roots, hypocotyl and seed);upward translocation to growing tips; however, translocation is likely unimportant in herbicidal action because EPTC is absorbed very near its site of action; susceptible weeds are controlled as they germinate; established weeds are not controlled.

Mode of Action:

Not well understood.

Metabolic pathway inhibited:

May include inhibition of fatty acid and lipid biosynthesis; as well as gibberellin synthesis.

Basis of Selectivity:

Metabolized by tolerant species at the seed germination stage by enzymatic breakdown; seed food reserves also allow seedling to outgrow effect.


Inhibits shoot growth of germinating seedlings to a greater degree than roots; induces abnormal growth and emergence of leaves from coleoptiles in grasses; kinking of the first internode into a zigzag pattern is often apparent; leaves of affected plants often appear darker green than tolerant plants; in BLW symptoms are less specific with growth generally inhibited, leaves cupped and having necrotic tissues around edges.


Intermediate (1- 4 months); provides season long control with no soil residues in the following year to limit rotations.


Oral LD50 = 1652 mg/kg - moderately toxic (EPTAM = 1325-1500 mg/kg - moderately toxic).

Additional comments:

EPTC can be applied PPI in corn, but only with a safener (R25788) packaged in ERADICANE products.