For everyone's safety, be patient after pesticides have been applied

How long do you need to wait after a pesticide has been applied before returning to the treated area? It depends... on what is indicated on the label.

Generally, the instructions on a pesticide label indicate a waiting period between a pesticide application and the time for a safe return to the treated site, whether outdoors or indoors. There are two types of requirements to control access to a site after pesticide application: the re-entry interval and the restricted-entry interval (REI). Depending on the case, either one or both may be found on labels.

These requirements are intended to reduce the risk of human exposure to pesticides and protect health. Complying with re-entry and restricted-entry intervals (REI) is a legal requirement under the Pest Control Products Act (PCPA) and an essential part of the pesticide safety.

Re-entry interval

The re-entry interval is the period during which no one, including workers, should enter a site that has been treated with pesticides. The applicator may be required to inform people who may enter a treated area when it is safe to do so, either verbally or in writing—such as through posted signage.

This term is usually used for pesticides applied indoors, such as for pest control in buildings, industrial uses, and household pesticides, and for pesticide use on turf.

Examples of re-entry interval statements found on pesticide labels

• Do not enter until residues have dried.
• Do not enter or allow entry into treated areas for 2 hours following application. The commercial applicator is responsible for notifying workers, homeowners, and others of the re-entry interval requirement.
• Leave room closed for 1/2 hour. Ventilate room thoroughly before re-entry.
• Do not re-enter or allow re-entry into treated areas until the spray is dried.

Restricted-entry interval (REI)

The restricted-entry interval (REI) is the period during which workers, or any other person, must not perform manual labour in treated areas after a pesticide has been applied.

REIs are most often seen on the labels of commercial-class pesticides intended for agricultural use, but they are also found on labels of other pesticides, such as products used in horticulture or on golf courses.

Examples of REI statements found on pesticide labels

• Do not enter or allow workers to enter treated areas during the restricted-entry interval (REI) of 12 hours.
• Do not enter or allow the personnel to enter treated areas until 2 days after the treatment.

More details about REI can be found in the Understanding restricted-entry intervals for pesticides fact sheet.

Note

If you have difficulty distinguishing between the re-entry interval and the restricted-entry interval (REI) information on a label, remember that no one should enter a treated site until the waiting period has expired, regardless of how it is described. If the label provides information for the return of workers to the site, it will include instructions specifically applicable to them.

Users must follow the instructions on the most up-to-date labels.

Using a pesticide contrary to the label directions is a violation of the Pest Control Products Act.

Role of Health Canada's Pesticide Compliance Program (PCP)

The PCP is responsible for promoting, monitoring, and enforcing the Pest Control Products Act (PCPA). Health Canada inspectors verify that pesticide use complies with all label directions, including restricted-entry interval (REI) and re-entry intervals. When a violation is identified as a result of an inspection, enforcement actions are taken in accordance with Health Canada’s Compliance and enforcement policy for pesticides.

Read and follow the label

All pesticides registered in Canada have a Health Canada-approved label with a registration number. Read the pesticide label carefully, as it contains specific information on how to use it.

To find the most up-to-date label, use the Health Canada online label search tool, or search for “Health Canada pesticide labels” using your favourite search engine.