Rules regulating pesticide spraying vary widely by state
http://www.registerguard.com/csp/cms/sites/web/news/cityregion/25639653-57/drift-spray-oregon-california-product.csp
http://www.registerguard.com/csp/cms/sites/web/news/cityregion/25639653-57/drift-spray-oregon-california-product.csp
"The U.S. Environmental Protection Agency has spent the past decade considering adding warnings to herbicide product labels against applying the chemicals in ways that can result in drift, but has yet to mandate the change."
