U.S. Customs and Border Protection (USCBP) temporarily suspended operations at Montréal-Trudeau International Airport on Wednesday, July 29, 2026, causing the cancellation of approximately 20 U.S.-bound flights. The suspension was triggered by a strong odour identified as varnish from construction materials near the customs area.
The incident occurred during a $10-billion redevelopment project at Montréal-Trudeau Airport, one of the largest infrastructure transformations in the airport’s history. The ongoing construction, including painting work, generated the odour prompting the customs suspension, directly impacting cross-border departures on that day.
Response Measures and Inspection
Airport authorities increased ventilation in the affected customs zone immediately after detecting the varnish odour.
The Montreal Fire Department inspected the site and confirmed the odour did not pose any health risk to passengers or workers.
Passenger Impact and Advice
The temporary suspension caused significant delays for international travelers in addition to the cancellation of around 20 flights bound for the United States. Passengers were urged to check their flight status with their airlines before traveling to Montréal-Trudeau Airport. USCBP operations gradually resumed but delays were expected to persist.
Official Statements on the Incident
Airport officials posted on social media that every effort was being made to restore U.S. Customs operations quickly and thanked passengers for their patience and understanding. They emphasized the odour,
while unpleasant, did not pose a health risk. The airport website apologized for the inconvenience and provided contact information for questions regarding U.S. preclearance operations.
“USCBP operations are gradually resuming. However, passengers should expect delays. The temporary suspension was caused by the odour of varnish associated with painting work. While the odour may have been unpleasant, it did not pose any health risk. We thank passengers for their patience and understanding,” airport officials said.
Ongoing Redevelopment Context
Montréal-Trudeau International Airport is undergoing a decade-long $10-billion redevelopment project expected to continue major construction work over the next ten years. This extensive infrastructure transformation includes
ongoing painting and other upgrades that contributed to the incident causing the temporary customs suspension.
