Pesticide re-entry intervals (REI)

Re-entry into treated areas

People can be exposed to pesticides if they enter a treated area too soon after application. When treated plants are touched during work activities such as weeding, thinning, or brushing against plants, some pesticide may be transferred to skin. People in treated areas may also breathe fumes from a recent pesticide application. Restricted entry intervals or re-entry times have been established to prevent people from being exposed to pesticides immediately after application.

A restricted entry interval (REI) or re-entry time is the time after the end of a pesticide application during which entry into the treated area is restricted. This time allows residues to disperse and not pose a risk.

• Post warning signs that state when treated areas can be re-entered.
• Only allow workers or other people into treated areas during restricted entry intervals if they use the proper protective clothing.

Restricted entry intervals on pesticide labels

REIs or restricted entry intervals are on most pesticide labels. When a REI is on a label, the REI must lapse before people can re-enter a treated area. If people need to enter a treated area before this time has lapsed, they must wear protective equipment. The pesticide label will say what protective equipment is needed.

Different pesticides will have different REIs, since pesticides vary widely in toxicity and hazard.   

Many pesticides have more than one different REI.  

• The REI can vary between crops. For example, the REI for raspberries could be 7 days while the REI for apples could be 14 days.
• The type of work activity also affects the REI. This is because the amount of human contact with treated foliage varies. For example, a REI could be 14 days for thinning, but only 48 hours for irrigating.

Restricted entry intervals of WorkSafeBC

WorkSafeBC Regulations for Occupational Health and Safety also have restrictions for workers re-entering areas treated with pesticides. Workers may not enter a treated field until they have waited the required re-entry interval.  Workers should follow the re-entry interval on the label. If there is no re-entry interval on the label, the following intervals should be used:

• 24 hours for a slightly toxic pesticide
• 48 hours for moderately or very toxic pesticides.

The relative toxicity of pesticides is listed in each Crop Production Guide. The following categories are used for these ratings:

Category	LD50
Slightly toxic	1000-2000
Moderately toxic	500 - 1000
Very toxic	0 - 500