General vs. Restricted Use Pesticides
In the US the Environmental Protection Agency (EPA) regulates pesticide use. Every pesticide must be registered as either General Use or Restricted Use. The product label contains very specific information and product use instructions. Unlike other consumer products pesticides must be used only as specified on the product label.
Restricted Use pesticides can only be sold to, and use by, individuals holding a license issued by their state (usually the state department of agriculture). These pesticides are either highly toxic or environmentally hazardous, or both. Restricted Use pesticides are not available online.
General Use pesticides can be purchased by individuals for use on property they own (in a manner specified on the label) without a license. An applicator license is generally required, however, if you intend to apply these materials on property you don't own.