Environmental Protection
About 4 of every 50 questions on each state's practice exam (Alaska Core, Alabama General Standards, California Laws, Regulations and Basic Principles, Delaware Core, Florida Core, Georgia General Standards, Idaho Core Competency, Illinois General Standards, Illinois General Standards (Structural), Kansas General Exam, Louisiana General Standards, Louisiana Structural General Standards, Massachusetts Core, Maine Commercial Core, Missouri CORE, Montana Core, North Carolina Core, New Jersey Core, Nevada Core and Laws, New York Core, Ohio Commercial Core, Pennsylvania Core, Rhode Island Commercial Licensing, Texas General Standards (Agricultural), Texas General Standards (Structural), Virginia Core, Vermont Core, Washington Laws and Safety and West Virginia Core) come from this topic.
Sources checked
What to know
Never spray when the wind blows toward a sensitive area, and follow the label's drift limits, which EPA asks registrants to state as droplet size categories, release heights, minimum and maximum wind speeds and buffer zones. Know the difference between spray drift (droplets or dust carried through the air at or soon after application) and volatilization (pesticide vapor moving through the air), and that vapor pressure appears to have a major effect on volatilization. A temperature inversion has cooler air at the surface than above it; inversions form more strongly on clear nights and resist mixing when wind is under 5 mph, and one is present if air at 1 foot is cooler than at 10 feet. Read the Environmental Hazards section: under 40 CFR 156.85 an outdoor product with a fish LC50 of 1 ppm or less must say it is toxic to fish, and non-aquatic outdoor products must warn against contaminating water by cleaning equipment or disposing of wastes. Follow bee statements and the bee advisory box (no application until all petals have fallen where the label says so), and when a label refers to Bulletins Live! Two, obtain the Bulletin for your application month (available up to six months ahead) because its limits are enforceable. Apply when rain is not predicted for the next 24 hours, and when treating aquatic weeds, treat one-third to one-half of the water area at a time with 10 to 14 days between treatments. Leaching risk is highest in permeable, low-clay, low-organic-matter soils over a shallow water table, higher Koc means stronger binding to soil and less movement, and an air gap of at least twice the hose diameter prevents back-siphonage.
Where it comes from
- EPA, Introduction to Pesticide Drift; EPA, Pesticide Volatilization
- EPA, Improving Labels to Reduce Pesticide Drift; Purdue PPP-51, Stay on Target: Prevent Drift
- NDSU Extension AE1876, Understanding Air Temperature Inversions Relating to Pesticide Drift
- 40 CFR §§ 156.80, 156.85
- EPA Label Review Manual, Ch. 8 Environmental Hazards
- EPA, New Labeling for Neonicotinoid Pesticides; EPA, Endangered Species Protection Bulletins; Bulletins Live! Two Q&A
- NPIC, Groundwater Ubiquity Score (GUS); OSU Extension Pesticide Properties Database; Texas Agricultural Extension Service L-2430
Try a practice question
Which description matches how EPA defines pesticide spray drift?
- AAirborne movement of droplets or dust off target at or soon after application
- BDownward movement of dissolved pesticide through the soil profile toward groundwater
- CMovement of pesticide vapor off treated surfaces in the days after the spray has dried
- DTransport of pesticide off the site in rainwater flowing across the soil surface
Show the answer
Airborne movement of droplets or dust off target at or soon after application. EPA defines spray drift as the movement of pesticide dust or droplets through the air at the time of application or soon after. Vapor movement after drying is volatilization, which EPA treats separately; the other two describe leaching and runoff.
EPA, Introduction to Pesticide Drift