Development of new pesticide interim standards

Pesticides detected in Montana groundwater during

2011 testing

Detected in Helena and Billings, Dichlorprop targets post-emergent broadleaf weeds and brush (both annuals and perennials).

Used for weed control on residential lawns, sod farms, roadsides, industrial sites, rights-of-way, and forests.

The United States uses roughly 4 million pounds of dichlorprop-p annually. An estimated 60% of this is used on residential lawns .

Not used in agricultural applications.

Dichlorprop-p

The EPA classifies this compound as a toxin (Class D).

Review of available data has derived a interim human health standard of 0.3mg/L.

DEQ preliminary calculations have been confirmed by EPA Region 8.

Dichlorprop-p a herbicide

Myclobutanil- a fungicide

First detected in the Billings area, Myclobutanil is a fungicide. It has a number of food crop applications (grapes, strawberries and blueberries) and commercial or residential landscaping applications.

Myclobutanil

The EPA considers it a toxin (class E)

Review of available data has derived a interim human health standard of 0.2mg/L.

DEQ preliminary calculations have been confirmed by EPA Region 8.

Fipronil- an insecticideDetected in several locations (Gallatin River, Missoula and Helena) Fipronil is used to control a variety of insects including ants, beetles, cockroaches, fleas, ticks, termites, mole crickets, thrips, rootworms, and weevils.

Fipronil may be found in turf products, seed treatments, pet care products, baits, and termite treatments

It is registered for use on commercial and residential turf. There are currently three tick and flea control products with fipronil for use directly on pets.

Fipronil

The EPA does consider this compound a carcinogen (class C).

Review of available data has derived a interim human health standard of 0.001 mg/L.

DEQ preliminary calculations have been confirmed by EPA Region 8.