Page 38 - OHS, April 2020

FIRE SAFETY
Protecting Firefighters from Invisible Hazards
Whether responding to a carbon monoxide call or performing an overhaul and investigation, a gas detector could save your life or the lives of nearby civilians. BY HOLLY MAZZIA
34 Occupational Health & Safety | APRIL 2020
www.ohsonline.com
When firefighters attack a structure fire, the hazards to life and health are obvi- ous. The flames, the heavy smoke, and the extreme heat are clear reminders of what’s at stake.
What’s often overlooked, however, is the danger of gas hazards both during and after a fire. As infor- mation on the hidden dangers of fire smoke prolifer- ates, a growing number of firefighters are realizing that gas monitors are a vital part of their turnout gear. Atmospheric testing at fire scenes has shown that toxic fumes are present at every stage of the fire—and without a portable gas detector, there is no way to determine whether the air in the cold zone is actually safe to breathe.
Research has shown that toxic gasses linger at alarming levels well after the fire has been extin- guished. But because most firefighters do not carry portable gas detectors, they’re probably unaware of the danger and may remove their SCBA mask and risk inhaling toxic fumes.
Fire smoke is a complex mix of toxins, and hydro- gen cyanide (HCN) has emerged as one of the most common and dangerous. While carbon monoxide (CO) often gets public attention, HCN is commonly found alongside it, and together, they’re known as the
“toxic twins.” Both are asphyxiants, meaning they in- terfere with the body’s ability to process oxygen. In- dividually they’re dangerous. Together, they’re even more deadly.
In the past, HCN was not a concern after a typical house fire. But as the use of synthetic materials has replaced natural materials in the construction indus- try, HCN has become more prevalent. When heated, these fibers and petroleum-based products emit HCN at levels unseen by earlier firefighters.
While CO has almost always been a concern, the early signs of poisoning are difficult to detect and are often mistaken for the flu. Seemingly tailor- made to fool the unsuspecting, CO is invisible and odorless, so it’s impossible to detect without spe- cialized equipment.
The Dangers of Gases
The National Institute for Occupational Safety and Health (NIOSH) has determined that at 50 ppm, HCN can render someone unable to escape to safety and is therefore immediately dangerous to life and health (IDLH). However, even at much lower levels, the long-term health effects are a concern. At only 4.7 ppm, exposure should be limited to just fifteen min- utes per day.