Police arrested a 57-year-old man following the discovery of a suspected teargas canister at Heathrow Airport’s Terminal 4, forcing the temporary closure of the check-in area.
The incident occurred on Monday evening, prompting an evacuation that lasted for about three hours as emergency services investigated a potential hazardous materials threat. Terminal 4’s operations were briefly halted, with security officers and paramedics responding to passenger reports of discomfort.
Authorities confirmed that approximately 20 individuals experienced irritation symptoms, including burning sensations in the eyes, throat, and skin. Medical teams treated those affected at the scene, and officials noted that no life-threatening or lasting injuries were sustained.
Police later recovered a canister believed to contain CS spray, commonly known as teargas. This substance, often used in riot control, is designed to temporarily incapacitate by irritating the respiratory system and eyes. Investigators said the canister was the likely cause of the reactions experienced by passengers in the check-in area.
The arrested man is being held on suspicion of possession of a firearm, as CS spray falls under restricted weapon regulations in the UK, and for causing a public nuisance. Authorities emphasized that the case is not being treated as terrorism-related.
Initially, there was speculation that the reported symptoms could have been linked to “mass hysteria,” since officers could not immediately locate the source of the irritant. However, the discovery of the spray canister confirmed the substance’s presence within the terminal.
Police were alerted shortly before 5pm, with Terminal 4 reopening by 8.30pm once safety checks were completed. Airport officials reassured travelers that flight operations would continue with minimal disruption. Only minor delays were reported, and most scheduled departures went ahead as planned.
The incident has highlighted ongoing concerns over the security risks posed by hazardous substances in public transport hubs. Investigations are continuing to determine how the spray entered the airport and whether additional safety measures are required to prevent similar situations in the future.
