A device the size of a cellphone was an unsung hero in the Old East London explosion, potentially saving many lives in the lead-up to the devastating blast that rocked the area less than half an hour later.
Small sensors, or personal gas detectors, that firefighters were wearing on their vests while responding to a 911 call about a car slamming into a house alerted them to the first sign of an explosive in the air.
A natural gas line had been severed.
The warning gave firefighters vital minutes to arrange a street evacuation before the explosion that obliterated one house and severely damaged nine more, forcing hundreds in the area from their homes.
They are our first and last line of defence for our personal safety,
Carried in every London fire engine, the small four-gas detector is used when hazardous material, fire or natural gas are involved. It detects carbon monoxide, hydrogen sulphide, oxygen levels and something called a lower explosive limit (LEL) — the last, the alert so crucial before last Wednesday night’s blast.
Another detector is used to check for hydrogen cynanide.
While the four-gas sensor doesn’t detect natural gas, it detects the explosive limit of that gas, London firefighter Mike Lawrence said.
“Every engine has these on them. We wear them to medical calls and into any fire,” he said.
“This detector will let us know if something is in an explosive range, which is what happened the other night . . . they went in and realized it was explosive range.
“Every time there is a carbon monoxide call, we take these into the house.”
The detectors come in all different shapes and sizes, and prices vary from US$500 to $750, according to Gustavo Lopez, general manger of MSA Safety, which distributes the devices.
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“Fire departments should have them because you never know what you will come across. These products are designed with high-end and the most up-to-date technology to detect hazardous gas that can be a challenge in any type of industry out there,” he said.
He said almost all fire departments have the devices on hand.
“There sensors are very specific, so the LEL sensor for combustible gases, that is probably the sensor that went off. That sensor will detect any type of explosive gas. There are layers of protection built into them in terms of where the alarms are set — as that level is rising, the instrument will alarm,” Lopez said.
“It has to get over 100 per cent of LEL for it to be an explosive atmosphere, but those alarms are usually set at 10 per cent LEL, so you have plenty of time to get the people out — obviously, hopefully, prevent people getting hurt.”
The devices “may be expensive,” but using them is far better than risking losing lives, said Jamie Hillier of the Firefighters Association of Ontario.
“They are our first and last line of defence for our personal safety,” he said.