Around 20 people reported an injury but “no trace of any adverse substance was found” after officers were called to Heathrow, the Metropolitan Police has said.
Terminal 4 check-in was evacuated as a precaution on Monday evening while emergency services responded to a “potential hazardous material incident” at the airport, the London Fire Brigade said.
According to police, around 20 people had reported an injury, but no trace of any hazardous substance was found after officers conducted a thorough search of the area.
Emergency services have confirmed Terminal 4 is safe to reopen and we are doing everything we can to ensure all flights depart as planned today. We are very sorry for the disruption caused, the safety and security of our passengers and colleagues is our number one priority. We… pic.twitter.com/AykEmpgnKh
— Heathrow Airport (@HeathrowAirport) September 8, 2025
A London Ambulance Service spokesperson said a total of 21 patients had been treated and one had been taken to hospital while all the others had been discharged at the scene.
In a statement, a spokesperson for the force said: “On Monday, September 8 at 16:56hrs police were called to a potential hazardous materials incident at Heathrow Airport, Terminal Four.
“Specialist officers attended the scene alongside the London Fire Brigade and London Ambulance Service and conducted a thorough search of the area.
“No trace of any adverse substance was found.
“Around 20 people reported an injury. None were deemed to be life-threatening or life-changing. Enquiries are ongoing.”
Is Terminal 4 open at Heathrow Airport?
If you have a flight booked, you’ll not need to worry as flights from Terminal 4 are going ahead so far this morning.
At 8.27pm on Monday evening after the incident, the airport updated passengers by posting to X.
It said: “Emergency services have confirmed Terminal 4 is safe to reopen and we are doing everything we can to ensure all flights depart as planned today.
✅CLEARED: #HeathrowTerminal4 – Trains are now able to call at Heathrow Terminal 4 following the emergency services dealing with an incident
— National Rail (@nationalrailenq) September 8, 2025
“We are very sorry for the disruption caused, the safety and security of our passengers and colleagues is our number one priority.
“We encourage passengers to check with their airline for the latest information about their flight this evening and our colleagues will be on hand into the night to assist”.
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According to the Heathrow Airport website, flights are arriving and departing as usual, at the time of writing, with more expected to throughout the day.
Where does Heathrow Terminal 4 fly to?
Heathrow Terminal 4 flies to various European, North African, Middle Eastern, and Central Asian destinations served by airlines like Air France, Etihad Airways, KLM, Malaysia Airlines and Qatar Airways.
Major airlines operating from Terminal 4 include Air Algerie, Air Astana, Biman Bangladesh, China Southern, Gulf Air, Korean Air, Kuwait Airways, Royal Air Maroc, Saudia and Oman Air.
Keep up to date with the latest via the Heathrow Airport website (linked above) and X account. You can also keep an eye on updates from your airline or contact them.
