EPA announced the release of the Drift Reduction Technology (DRT) Program in today's Federal Register. EPA describes the DRT program as a "voluntary program based on this verification protocol to promote the use of technologies that have demonstrated their effectiveness in reducing the drift of agricultural pesticide spray application technologies."
Under this program, equipment manufacturers would measure the the % drift that was reduced following use of certain technologies and then submit this study to the EPA for review. These % reductions would be applied to the risk assessment for the pesticide product and will determine language than will then be placed in the final product label. Technologies that could be used to reduce drift include nozzle size, spray shields or even chemical adjuvants tank-mixed with the pesticide product. A "star rating" will be applied to the label dependent on the amount of reduction demonstrated by the selected technology. For example, the maximum rating (4 stars) is achieved when one demonstrates 90+% reduction in spray drift.
EPA intends to publicly post decisions made under the DRT on this web page (You may want to BOOKMARK this one!) EPA claims that, eventually, one will be able to "search tables for DRT-rated technology for ground boom and aerial applications by manufacturer and system pressure (psi)."
It is important to note that this is one component of an overall initiative by EPA to reduce spray drift from use of agricultural chemicals. Earlier this year, two key guidance documents were issued for public comment, including a human health risk assessment policy document and
an updated method for estimating spray drift exposures. Also earlier this year, EPA made some "game changing" decisions regarding Dow Agro's Enlist Duo label (a formulation of 2,4-D and glyphosate intended for use on crops engineered to be resistant to both herbicides) when it comes to spray drift, including specific combinations of nozzle types and resultant droplet size that will be allowed to apply the product.
The concept here is rather simple (increase droplet size to reduce the distance the chemicals travels from the site of application) yet requires massive amounts of information (air models, field deposition trials, wind tunnel studies) that could be misused in the developing EPA assessment procedures. Many smaller companies are likely to be put off by the combination of the data needed and the regulatory expertise needed to successfully get a sprayed pesticide on the market (or a new use).