Four fire engines and around 25 firefighters attended a carbon monoxide leak on Middlesex Street in the City of London.
Three people were evacuated from a flat. A further 50 to 100 people from a pub and neighbouring flats were asked to stand outside a 25 metre cordon as a precaution. There were no reports of any injuries.
Firefighters used specialist equipment to carry out a systematic sweep of the building to check for elevated readings of chemical substances and isolated the gas supply. Crews ensured no elevated readings remained before leaving the scene.
A London Fire Brigade spokesperson said: “You can't taste, see or smell CO fumes, but it can kill in minutes.
"It's really important to fit a CO alarm in all rooms containing fuel burning appliances, ensuring that the alarm is able to be heard throughout the property. When sleeping, it is important that your alarm would wake you if it sounds.
"It’s also a good idea to familiarise yourself with the signs of carbon monoxide poisoning and learn what to do if you suspect someone may be affected.”
The Brigade was called at 1343 and the incident was over for firefighters by 1627. Crews from Shoreditch, Bethnal Green, Islington and Euston fire stations attended the scene.
CO poisoning symptoms:
These symptoms also apply to your pets – so keep an eye on them too. Poisoning symptoms can easily be confused with just feeling unwell, which is why CO poisoning is so dangerous, and so often missed.