What is the difference between a deposit and a residue?
The pesticide that remains on the treated suface is called a deposit. A residue is a deposit which remains on the surface for an extended period of time.
How can long-lasting residues be desireable? Undesireable?
Long lasting residues are desireable because of long-lasting protection, less frequent application, and are economical. Undesireable effects of residues are hazards to consumers, workers, or they may interfere with future crop production.
What is a tolerance? When must a tolerance be set?
Tolerance is the established maximum amout of residue which may remain on a food or crop. A tolerance must be set before the pesticide is registered for use on food or feed.
Can a food or feed crop have more than the set tolerance of a pesticide on it and still be legally marketed?
No. It is subject to condemnation and siezure by federal and state regulatory agencies.
What information determines the setting of a tolerance?
The results of toxicity studies on animals and the environment.
At least what margin of safety ("safety factor") is used in setting tolerances?
Does the marketed food sometimes have less pesticide residue than the set tolerances? When?
Yes. Food may have no residues, may never have been treated, was at less than the maximum dose, and the residues may have degraded.
Can food crops and animals contiain pesticide residues even when they are not directly sprayed by the pesticide?
Yes. Due to indirect contact with a chemical.
When are Negligible Residue Tolerances set?
When a very small residue is likely to be on food or feed at harvest.
When are Days to Slaughter or Days to Harvest important? What are they for?
It is the least number of days between the last pesticide application and the harvest or slaughter day. To assume that the residue on the commodities are under the set tolerances.
It is necessary for every pesticide to be registered before it is sold or used?
Yes. Every pesticide is registered federally by EPA.
What are some of the types of information that the Environmental Protection Agency reviews before registering a pesticide?
EPA reviews toxicity studies, wildlife and environmental studies, breakdown, and residue studies, chemical studies, etc.