Pesticide Status of Propionic Acid – an update

Mike Rankin
Crops and Soils Agent
University of Wisconsin - Extension

About this time last year, EPA initiated the process of registering certain applications of propionic acid as a pesticidal application.  One such application is using the acid during hay baling.  Thus, custom hay balers using the product  would need to be certified and licensed as commercial applicators.  The year 2001 was designated a "grace" year by WDATCP for manufacturers and labelers to get products registered with EPA (or at least get the paperwork submitted). 

Well, EPA has not gotten around to registering the new labels as quickly as they initially thought.  At this point in time, there doesn't appear to be any propionic acid product with the new label containing an EPA Registration Number.  Dave Fredrickson, WDATCP Compliance Section, indicated that we might see several products with the new label by June/July of this year.

Basically, we currently sit in the same position we were in last year with the pertinent question being, "Should a custom hay baler get certified for the upcoming growing season?"   The response we are getting from Madison is: "Yes".  Their reasons are two-fold.  First, product with the new label will appear in the market sooner or later.  Therefore, it is in the custom baler's best interest to get certified because if a big baling job is lined up and the replacement product has the new label, the baler legally cannot make that application.

Second, if during an investigation WDATCP finds out that a manufacturer has not made any attempt to get their product registered, WDATCP will put a "stop sale" on the product, including product owned by a custom baler.  In other words, a custom baler should inquire of his/her supplier whether or not their product is in the process of being registered with EPA.

Below is a summary of the information presented last year pertaining to the change in pesticide status of propionic acid:

1.         If propionic acid is labeled for use to have pesticidal activity (e.g., application to hay during

2.         baling, application to silage or grain during harvest or filling, etc.), then manufacturers and labelers must register their product with EPA (and the manufacturer must have an establishment number)

3.         Dealers distributing the product (i.e., they do not repackage it or slap their own label on it) need not be licensed.

4.         Once a dealer distributor or applicator has a registered product, then all the provisions regarding bulk storage, certification, and licensing applies.

5.         Propionic acid is NOT a restricted-use pesticide.

6.         Individuals custom applying the acid during baling operations or corn harvest and using product that does not have a pesticide label, may apply the product as they always have (i.e. without being certified).

7.         Individuals custom applying the acid during baling operations or corn harvest using product with a pesticide label must be certified AND licensed as a commercial applicator in Field and Vegetable Crops (category 1.1), and they must obtain a pesticide application business license.

8.         Farmers applying the acid for their own use do not need to be certified.

9.         Farmers may custom apply (get paid for it) the acid for up to 3 different producers or up to 500 acres in any calendar year without being certified.