Mary wanted to spray her tomatoes with a pesticide product, but she wasn't sure if the product she chose could be used on them.
"Larry!" she called into the other room. "Do you think I can put this product on my tomatoes?" Larry entered the room and started to read the label. "I think so...Yeah, there it is," he said while pointing to the label.
"I'm a little worried about eating something that has a pesticide on it. How long do you think we should wait before eating the tomatoes?" she asked.
"I don't know," said Larry. Let me see if I can find anything on the internet." After doing some searching, he said, "Why don't you call the National Pesticide Information Center (NPIC)? From what I've seen on their website, I think they could help."
The NPIC specialist told Mary that the information she was looking for was called "preharvest interval" (PHI). She explained that the preharvest interval tells you how long it takes for the pesticide residue to break down to a level that the U.S. EPA considers a reasonably low risk. Testing is required on each kind of fruit and vegetable listed to figure out the best harvest interval for each pesticide on each particular food.
"I can't seem to find the preharvest interval on my label, though," Mary said. The specialist explained to Mary that the preharvest interval information can be found in different places on various labels. Sometimes it is at the beginning of the application directions and other times it is in a table next to the appropriate fruit or vegetable. If someone cannot find the PHI, they may choose to contact the product's manufacturer for that information. The manufacturer's contact information can be found on the product label or on NPIC's list of manufacturers.
The NPIC specialist also discussed other ways to help Mary and her husband limit the amount of pesticide residues from their vegetable garden. These ideas included washing all fruits and vegetables and trimming or peeling them when possible. People can always choose to wait longer than the preharvest interval in order to let the pesticides break down further.