05
Oct
Oregon Temporarily Bans Herbicide Known to Kill Trees… after the Herbicide Is Found to Kill Trees
(Beyond Pesticides, October 5, 2018) The Oregon Department of Agriculture (ODA) is temporarily banning the use of any products containing the herbicide aminocyclopyrachlor to rights-of-way after finding widespread tree deaths along a scenic highway that cuts across the center of the state. While Oregon is the first state to ban the chemical, it is not the first instance of the pesticide killing stands of established, otherwise healthy trees. In 2014, chemical company DuPont settled a class action lawsuit totaling over $1.8 million in civil penalties after its aminocyclopyrachlor product Imprelis was cited for misbranding and failure to report adverse incidents of trees dying after applications.
Oregon first encountered evidence of abnormal growths, curling, and die-backs of coniferous trees along roadsides back in 2012. A report on tree damage produced by ODA in 2015 narrowed the cause down to the use of aminocyclopyrachlor-based herbicides, including DuPont’s Imprelis, as well as Bayer’s Perspective. At the time, ODA indicated the U.S. Forest Service (USFS) had sent letters to the agency requesting the cessation of aminocyclopyrachlor use along roadsides. Oregon officials indicate that the contractor did stop spraying the chemical in areas cited in the report.
An update to the first report, published in September 2018, found that die-off and damage increased alongside the highway where trees were sprayed. The elevated damage outlined by the updated report led to ODA’s temporary ban, which will be in effect until late March, 2019. The USFS also announced plans to log a section of the highway impacted by the tree die-off. “It’s a public safety issue . . .you just never know when a tree is going to go,” said Forest Service spokeswoman Kassidy Kern to Oregon Public Broadcasting. The move will log trees that are in some cases hundreds of years old.
This ecological tragedy and threat to public safety would have been easy to avoid if U.S. Environmental Protection Agency (EPA) and ODA had taken a more precautionary approach to regulating this new chemical. Aminocyclopyrachlor was given a conditional registration by EPA in 2009. At the time, DuPont was the primary registrant for the pesticide, and commercialized the product Imprelis for consumer use. However, soon after hitting the market, landscapers and golf courses began reporting the death of trees as a result of runoff or drift from the application of Imprelis to turfgrass areas. Reports initially indicated the deaths of millions of dollars worth of Norway spruce and white pine were mysterious, however it quickly became apparent that Imprelis was at fault. This led EPA to issue a stop use order to DuPont in 2011.
EPA cited the company for misbranding on the product’s label, as Imprelis did not include Norway spruce or white pine as a target species. The agency also later cited the company for not reporting documented adverse incidents. These regulatory actions culminated in DuPont voluntarily withdrawing Imprelis from the market, and paying the aforementioned civil fine of over $1.8 million in 2014.
However, although the product Imprelis was removed from the market, its active ingredient aminocyclopyrachlor remained. DuPont’s herbicide division was purchased by Bayer, which became the primary registrant for the herbicide, and produced the product Perspective. The only substantive change, made after the millions of dollars of damage, is that EPA did not approve Perspective for use on commercial turfgrass sites, such as lawns and golf courses. But the agency left in place allowed uses on “industrial” turfgrass sites, which include right-of-ways, highways, airports, railroads, as well as allowed uses on wildlife management areas. The chemical itself is still conditionally registered, however EPA has received outstanding data it required, and is now in the process of evaluating its acceptability for full registration. There is no indication from the agency that it will further restrict roadside uses.
Oregon Public Broadcasting indicates that the herbicide was sprayed by a contractor alongside Oregon highways for four years up until 2015, the year the ODA report was released. However, it was widely known as early as the second year of the spraying that this chemical caused significant damage to non-target trees. As a result, many are questioning why ODA took so long to issue its temporary ban on the chemical.
Aminocyclopyrachlor is a picolinic class chemical, which is similar to herbicides such as aminopyralid, clopyralid, and picloram. These chemicals are selective, targeting weeds but not affecting grass species. However, when, for instance, cows or horses feed on hay or other grasses sprayed with these chemicals, they can pass through these animals and end up in their manure. When composted, manure containing even minute levels of these chemicals, as low as 1 to 10 parts per billion, can result in damage to vegetables and other sensitive crops grown in the contaminated media. The U.S. composting council lists this class of chemicals as persistent herbicides, and has called on manufacturers to withdraw their registrations, and EPA and state agencies to take decisive action to stop economic and environmental damage caused by these chemicals.
Right-of-way management does not have to involve the regular use of persistent herbicides that could harm non-target species. Mechanical trimmers, biological controls such as goats, and the establishment of low-maintenance native vegetation provide non-toxic alternatives to pesticide use. More information about roadside weed management can be found on Beyond Pesticides’ article, The Right Way to Vegetation Management.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Oregon Public Broadcasting, ODA
I was delivered aminocyclopyrachol contaminated compost. I cannot get a straight answer from Oregon Department of Agriculture. The minimum reporting levels MRL of .010ppm are listed on all samples except two samples that have 0.04 and 0.03. The MLR for those samples is listed as <0.04 and <0.03.
Please help
June 24th, 2020 at 4:27 pm