On July 29, 2026, U.S. Customs and Border Protection (USCBP) temporarily suspended operations at Montréal-Trudeau International Airport (YUL) due to a strong odour of varnish associated with painting work from nearby construction materials. Around 20 U.S.-bound flights were cancelled as a result of the stoppage, which affected passengers travelling to destinations in the United States.
Operational Response and Passenger Advisories
Montréal-Trudeau International Airport officials stated on social media that every effort was being made to resume USCBP operations as quickly as possible. Ventilation in the affected customs area was increased following the incident. The Montreal Fire Department inspected the site and confirmed the odour did
not pose a health risk. U.S. Customs operations were gradually resuming on the same day but delays were expected. Passengers were encouraged to check the status of their flights with their airlines before travelling to the airport due to possible ongoing cancellations and delays.
Montréal-Trudeau Airport is currently undergoing a $10-billion redevelopment project, with major construction expected to continue over the next decade. The odour originated from materials related to this ongoing construction near the customs area.










