Montréal-Pierre Elliott Trudeau Airport sees US flight cancellations and delays after varnish odour shuts down customs. Here's the latest update passengers need to know

Passengers travelling to the United States from Montréal-Pierre Elliott Trudeau International Airport faced major disruptions on Wednesday morning after an odour linked to painting work forced the temporary suspension of U.S. Customs and Border Protection (USCBP) operations.

In its latest update, the airport confirmed that USCBP operations are gradually resuming, but warned that travellers should still expect delays as normal processing returns.

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"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."



The incident led to several flights to the United States being cancelled or delayed during the busy morning travel period, leaving hundreds of passengers waiting for updates.

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What caused the disruption at Montréal-Pierre Elliott Trudeau International Airport?

According to Aéroports de Montréal (ADM), the disruption began after an odour from construction material was detected inside the U.S. Customs and Border Protection preclearance area.

Airport officials later clarified that the smell came from interior painting work, specifically varnish used during ongoing maintenance. Because of the strong odour, USCBP temporarily suspended its operations while the situation was assessed.

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ADM initially advised passengers to contact their airlines before travelling to the airport, saying: "Every effort is being made to resume operations as quickly as possible."

Airport officials later emphasized that although the smell was unpleasant, it did not pose any health risk.

Flights to the United States cancelled and delayed

The temporary closure of the US preclearance area meant travellers could not complete customs processing required before boarding flights to the United States.

As a result, multiple departures were either cancelled or significantly delayed. By around 11:15 a.m., airport officials said US Customs operations had begun returning gradually, but warned passengers that delays were still expected throughout the day.

Travellers were urged to keep checking with their airlines for the latest information regarding their flights.

Airport says varnish smell was unpleasant but not dangerous

After investigating the incident, ADM confirmed the smell was caused by varnish associated with interior painting work. Officials stressed there was no danger to passengers or staff, saying the odour may have been uncomfortable but did not present any health concerns.

The airport thanked travellers for their patience while normal operations resumed.

What passengers should do now

Although US Customs operations have resumed, airport officials continue to warn that travellers heading to the United States should expect delays while processing returns to normal.

Passengers are advised to:

• Check their flight status before leaving for the airport.
• Stay in contact with their airline for schedule changes.
• Allow additional time for U.S. preclearance procedures.
• Contact US Customs and Border Protection directly for questions related to preclearance operations.

With customs processing gradually returning to normal, airport authorities expect operations to stabilize, but travellers should remain prepared for longer wait times until the backlog is cleared.