In Montréal, the alert siren is used to quickly notify the public in the event of a toxic product release. Several industrial facilities within city limits are equipped with public warning sirens. Please view the map for details on the location of these facilities, the substance present on the site, and the alert warning zone or area potentially affected by a release.

The siren produces a rising and descending tone that lasts for three minutes. 

The warning siren does not sound the same as the interior sirens of some factories in eastern Montréal. These can be heard every Tuesday around 11 a.m. 

Listen to the sound of a warning siren in this video.

If you hear the siren, follow the instructions below to minimize your exposure to toxic products: 

• Quickly enter the nearest building to avoid breathing in a toxic product. 

• Close the doors, windows and ventilation systemsto keep a toxic product out. 

• Follow the instructions issued by public authorities and stay informed via the media. 

• Leave your children at the childcare centre or school to avoid any exposure to the toxic substance. 

• Avoid using your phone to keep the lines free, unless you are calling 911 to report an emergency. 

If you live near an industrial establishment, subscribe to Montréal’s Notices and Alerts. You will be notified by text message and e-mail if a toxic substance is released.

Each year, Montréal plans a siren test in collaboration with factories or industrial warehouses within city limits to raise awareness among nearby residents and ensure that all equipment is in proper working order.