The Environmental Protection Agency is proposing to cancel all registrations of the pesticide pentachloronitrobenzene (PCNB), a fungicide used to control plant diseases in both agricultural and non-agricultural sites. The agency states the reason for its proposed ban products with PCNB as the active ingredient is because of “significant ecological and human health risks.”

Brand names of products with PCNB include Premion, Turfcide, Blocker, and Terraclor. Currently, fungicides with PCNB are used to control plant diseases in vegetable crops such as broccoli, cabbage, kale, potato, and others. Non-agricultural uses include turf at golf courses, athletic fields, and industrial parks, sod farms. It is also used on flowering bulbs and other ornamentals. 

The EPA cites human health risks from PCNB itself and also manufacturing impurities in PCNB formulations for pesticide handlers, bystanders from spray drift and people who use athletic fields. Their studies found possible health risks that included both cancer and non-cancer concerns along with effects on people’s thyroids.

Besides the human health concerns, a separate EPA study found that PCNB posed possible risks to various animals and plants including fish, amphibians, birds, reptiles, and mammals.

Other countries including Australia, Canada, New Zealand, and the European Union have already cancelled uses of PCNB.

After a public comment period ending this month, the EPA will review the comments and then make a final decision on the cancellation of PCNB products. AMVAC Chemical Corporation, a manufacturer of pesticide products including fungicides with PCNB has requested the EPA extend the comment period an extra 90 days stating in a public comment that “as a sole registrant we request this additional time to consult internally and formulate our responses.”

In a letter to the EPA, the Golf Course Superintendents Association of America (GCSAA) state that loss of products with PCNB would mean golf courses would have to use more expensive products, and use more different products to make up for the loss.

Alternatives

The EPA worked with the U.S. Dept. of Agriculture and the pesticide industry to identify other fungicides to use in place of PCNB including azoxystrobin, pyraclostrobin, tebuconazole, propiconazole, and Bacillus subtillus (a bacteria used as a microbial pesticide).

To read more about the EPA’s proposal and other public comments go to the review docket at regulations.gov/docket/EPA-HQ-OPP-2015-0348