What is a re-entry interval (REI)?
Re-entry interval (REI) is the term used in BC pest management for the time between when a product is applied and when people can safely re-enter the treated area. REIs appear on every PMRA-registered product label — they're not advisory but legally required. A BC-licensed pest professional is obligated to communicate the REI to the homeowner before leaving the property. REIs exist because liquid pesticide formulations need time to dry, bind to surfaces, or off-gas to ambient levels below the exposure threshold established in the product's safety data. Once the REI has passed and surfaces are dry to the touch, the product is either fully bound to the substrate (crack-and-crevice applications) or below detectable residual concentration (exterior perimeter treatments). The REIs listed below are standard for Wild Pest's protocols. If you have a sensitive household (asthma, pregnant occupant, infant, caged birds), see the 'When to extend' section below for adjustments.
REI by treatment type
| Treatment type | REI | Notes |
|---|---|---|
| Interior crack-and-crevice spray | 1 hour | Standard residential. Pets and children out during application and until dry. |
| Exterior perimeter spray | 2-4 hours | Yard access after dry; rain within 1 hour of application may reduce residual but doesn't extend the REI. |
| Gel bait application | Immediate | No liquid application; re-entry after tech leaves is fine. Bait is in enclosed locations. |
| Tamper-resistant bait stations only | Immediate | No spray applied; stations are closed. Immediate re-entry. |
| Heat treatment (bed bugs) | 4-6 hours | Wait for room to return to normal temperature after equipment removal. Typically 4-6 hours post-equipment-pull. |
| Wasp dust treatment | Immediate (exterior) | Stay 5 m from nest area for 24 hours as nest activity declines — safety, not chemistry. |
| Rodent inspection only | Immediate | No treatment applied. |
| Fumigation (rare, structural) | Per specialist instruction | Wild Pest does not perform structural fumigation. Refer to specialist for that REI. |
When to extend the wait
- Asthma, COPD, or respiratory condition in any household member: extend interior RE to 3-4 hours; ensure cross-ventilation during and after.
- Pregnant women: standard REIs are considered safe by PMRA; extending to 3 hours is reasonable for additional peace of mind.
- Crawling infants (under 18 months): standard 1-hour dry time plus 2 additional hours of ventilation before bringing infant back to treated floor areas.
- Caged birds: extend exclusion to 4-6 hours due to avian respiratory sensitivity to pyrethroid vapours.
- Aquariums: maintain cover and pump-off until full dry interval complete; then resume normal operation.
- Chemical sensitivity / Long-COVID chemical sensitivity: discuss with us on booking. We can use low-volatility formulations and extended REIs.
How to confirm the area is ready
The simplest check: touch a treated surface with a gloved hand or tissue. If dry to the touch, the REI has been met in practice. You should not smell strong chemical odour in living areas after a standard crack-and-crevice treatment — the product was applied inside voids, not open surfaces. Any residual odour from solvents typically clears within the REI with normal ventilation. For exterior treatment: check whether pooling water is still visible on treated surfaces. If the spray has dried and weather is not actively raining, re-entry is appropriate. For heat treatment: the room should feel at or below normal room temperature (under 30°C). Some areas of the home may take longer to cool than others — attic-adjacent rooms take longest. Use a thermometer if unsure.
What the REI is not
The REI is not the 'danger window.' It's not the case that re-entering at 59 minutes causes harm and 61 minutes is safe. The REI is a regulatory margin built into PMRA labelling to account for worst-case scenarios: maximum application rate, minimum ventilation, most sensitive population. For a healthy adult in a well-ventilated home where a professional applied a standard residential rate, the actual exposure risk drops off much faster than the REI. The implication: if you need to return briefly during the REI (forgot something), a short visit is not an emergency. Step in, get what you need, step out. If you have a medical condition or pregnancy, avoid this — stick to the extended guidance above.