The Latest on Pentachloronitrobenzene (PCNB)

*****UPDATE; 8/22/2011: The Chief Judge for the US District Court of the District of Columbia has issued a judgment vacating the EPA’s stop sale order on American Vanguard Corporation’s sales of pentachloronitrobenzene (PCNB). What this means for pricing and immediate distribution is unclear, including whether PCNB will be available in time for snow mold applications, please contact your sales representatives for more information on this matter. The full press release from American Vanguard can be found here.

On August 12th, 2010 the Environmental Protection Agency (EPA) issued a
Stop Sale, Use, or Removal Order to American Vanguard Corporation (AMVAC)
for technical grade PCNB 95% (EPA Registration Number 5481-197). The Stop
Sale Order was issed due to the potential violation of the Federal Insecticide,
Fungicide, and Rodenticide Act (FIFRA) Section 12(a)(1)(C) , 7 U.S.C. §
136j(a)(1)(C), which states that any distribution or sale of any registered pesticide product for which the Confidential Statement of Formula (CSF) does not accurately reflect the composition of the product is illegal.
The EPA took enforcement action after EPA laboratory analysis of AMVAC’s
registered PCNB technical grade 95% found significant levels of impurities
of highly toxicological significance not reported in the CSF. Australia
and Canada have taken steps in the past year to limit distribution of technical
grade PCNB 95% because of these impurities. A link to EPA’s announcement
concerning PCNB can be found here, and a pdf file of the Stop Sale, Use, or Removal Order issued to AMVAC can be found here.

On August 27th, 2010 AMVAC filed suit against the EPA seeking emergency
and injunctive relief from the Stop Sale, Use or Removal Order on the grounds
that the agency has known about these toxicological impurities for 20 years
and never before required these impurities be reported on the CSF. On September
3rd, 2010 the EPA issued a release denying relief from the Stop Sale Order.
The full release from AMVAC can be found here.

What does this mean for you in the turfgrass industry?

This latest ruling only affects golf course turf management, as use of PCNB on home lawns and golf course roughs was removed from the label on July 15th, 2009. An entire history of EPA rulings on PCNB since 2005 can be found here ( The Stop Sale Order states that distributors and end users who possess PCNB may use up current supplies, but that manufacturers cannot fulfill current orders. This means that if you are a soft goods distributor or golf course superintendent and you don’t have any PCNB in stock, you will not be able to obtain any until the Stop Sale Order is lifted. With the impending winter season fast approaching, lifting of the order in time for 2010 applications seems highly unlikely.

Many golf course superintendents spent far more than budgeted on pesticide
applications during the summer of 2010 because of abnormally high disease
pressures. This latest ruling further complicates financial matters for
many superintendents because of the comparative affordability of PCNB-based
products over most other fungicide mixtures for the control of snow mold
diseases on turfgrass. To put it simply, while other fungicide combinations
are more effective than PCNB-based fungicides, no other fungicide provides
the combination of effectiveness and affordability of PCNB-based products.

To aid the transition away from PCNB-based programs, Dr. Jim Kerns and
Paul Koch at the University of Wisconsin have created a series of snow mold
control programs and rated them on a scale from “Good” to “Supreme.”
While specific costs of each program will vary based on your sales representative,
in general programs rated as “Good” or “Better” will be more afordable than those programs rates as “Best” or “Supreme.” Those recommended programs can be found in the link below, reprinted from the Wisconsin Turfgrass Association Newsletter with the permission of Tom Schwab. In addition, results from the 2008-2009 and 2009-2010 University of Wisconsin Snow Mold Trials can be used in concert with the program recommendations from Paul and Jim to aid in making the best selection
for your specific situation.

Snow mold program recommendation for life after PCNB

The transition from PCNB-based fungicide programs for the control of snow
mold to other non-PCNB fungicides in such a short period of time can be
frustrating and confusing. If you have any further questions or comments
on what is best for your facility please do not hesitate to contact Paul Koch or Jim