Carbon monoxide and hydrogen cyanide are the silent killers that fire-fighters must be protected from
Today’s fires are more hazardous than ever. The reason for this is not that residential and office fires are hotter or somehow more dangerous, but rather that the smoke associated with these fires is more toxic than ever. Inhaling this smoke can kill a fire-fighter immediately or cause chronic health problems.
This is such a big problem that many organisations are changing the way they fight fires. Inhaling smoke used to be part of a firefighter’s job, but now that they realise how dangerous it is to do so, firefighters are increasingly using self-contained breathing apparatuses (SCBAs) during fire overhaul operations.
Another safety measure that some organisations are using is deploying wireless gas-detection systems when they fight and overhaul a fire. These gas-detection systems can be deployed rapidly and give commanders the information they need to determine when the air at a fire scene is safe enough to breathe. Monitors are being deployed as personal monitors as well as in the command and EMS vehicles, so that all fire personnel can protect themselves from harmful smoke.
The “toxic twins”
The most dangerous components in fire smoke are carbon monoxide (CO) and hydrogen cyanide (HCN) gases, sometimes known as the “toxic twins.” Carbon monoxide is produced when materials containing carbon, such as wood or plastic, burn in an area where there is insufficient oxygen to burn completely. CO can cause tissue hypoxia when inhaled, which prevents the blood from carrying sufficient oxygen, and can cause dizziness, nausea, headache and, at higher concentrations, convulsions, tachycardia (excessively rapid heartbeat) and death.
Like CO, HCN is an invisible gas that cannot be detected by the colour or the amount of smoke emitted by a fire. HCN is created as a result of burning laminates, synthetics, foams, plastics and wood—many of the materials found in furniture, PCs/office equipment, PVC pipe, carpet and upholstery items in homes and offices. While the dangers of CO have been long understood, the health risks of cyanide are now considered a substantial component of smoke inhalation. Exposure to large amounts of cyanide can cause convulsions, unconsciousness or death.
When inhaled together, the “toxic twins” can have a synergistic effect, experts say, causing even more harm. The time it takes for a person to become incapacitated by HCN gas is reduced if they inhale CO at the same time. At high HCN concentrations (>200 ppm), a person becomes incapacitated in two minutes or less. Once incapacitated, they continue to inhale the HCN/CO mixture for as long as they continue breathing.
While the majority of deaths may be attributed to CO inhalation alone, incapacitation due to inhaling HCN facilitates the process. This one-two punch is why HCN and CO are called the “toxic twins.”
These gases also present long-term dangers: Firefighters are now developing chronic illnesses, including cancers and cardiac-related illnesses like never before. In a 2006 study, University of Cincinnati(UC) environmental health researchers determined that firefighters are significantly more likely to develop four different types of cancer than workers in other fields.
The researchers found, for example, that firefighters are twice as likely to develop testicular cancer than non-firefighters and have significantly higher rates of non-Hodgkin’s lymphoma and prostate cancer. They also confirmed findings that firefighters are at greater risk for multiple myeloma (a cancer of the plasma cells).
New operating procedures called for
There is a growing awareness now that emergency responders must change the way they fight fires. The Fire Smoke Coalition (www.firesmoke.org) is a group that’s working hard to increase that awareness. Based in Indianapolis, the 501(c) (3) nonprofit organisation provides information and conducts hands-on workshops for firefighters and medical personnel focused on the protection against and the prevention and detection of smoke dangers. The workshops include global classroom and hands-on practical training that educate firefighters and others about the risk of fire-smoke exposure based on the latest research and institutional knowledge. The symposiums provide information that dispels the myths and misunderstandings about the threat of HCN exposure. The information also warns attendees about the long-term health effects of exposure.
One of the founders of the Fire Smoke Coalition is Capt. Rob Schnepp of the Alameda County Fire Department in California. Capt. Schnepp states, “By raising awareness based on the latest research, we can eventually trigger a paradigm shift whereby fire smoke is scrutinised and appreciated for its impact on acute and chronic health of firefighters and its impact on civilians who get exposed.”
“I think the effort is a game changer for our profession,” Schnepp says. “There are agencies that have made instant, and in some cases, widespread changes. There’s a huge movement now of departments doing more gas detection and monitoring, wearing air during overhauls and carrying cyanide antidote kits. There are a lot of people really embracing the message.”
Wireless gas detection keeps firefighters safe
Many of the toxic gases, including HCN and CO found at fire scenes, can only be detected with gas-detection instruments. Not only are today’s gas detectors more effective than ever, but they can now be connected wirelessly to create a system that makes fire overhaul much safer. A typical configuration might include :
One or more area monitors, such as RAE Systems’ AreaRAE • multi-gas detection system (this could also be mounted near the command center or trucks).
Personal monitors, such as RAE Systems’ ToxiRAE Pro or, or • multigas monitor such as the MultiRAE.
A real-time monitoring and control platform, such as RAE • Systems’ ProRAE Guardian.
The area monitor provides information on a number of different gases, including HCN, CO, and other hazardous gases. When equipped with a wireless interface, it can transmit continuous data readings in real time to the command centre. In addition to the area monitor, individual firefighters can be outfitted with personal monitors.
Personal monitors are available that can detect volatile organic compounds (VOCs), toxic gases and oxygen, as well as combustible gases and vapours. These personal monitors can also be wirelessly connected to a monitoring network and the readings recorded to give a continuous log of time-based exposure levels. This log can then be used to verify that OSHA exposure levels for worker safety are not exceeded.
Tying the system together is the real-time monitoring and control software. This platform collects data from each instrument and provides a comprehensive real-time display of gas and radiation data at any time and from any location. This data gives commanders a full picture of the threats at the overhaul site and allows them to determine whether it is safe for firefighters at the scene to remove their SCBA facemasks and to direct firefighters to potential hotspots.
Lt. Mike Becker, an 18-year veteran of the Longmont (Colorado) Fire Department, is a proponent of using wireless gas-detection systems at a fireground. His department uses detection equipment to help them determine their strategy for fighting a fire, as well as for keeping personnel safe. “I’ve gotten hits on HCN with meters at fires before,” says Becker, “If you truly know how to use the instrument, it can be your best friend when you need to determine the safety of an environment; it keeps everyone safe and healthy.”
Improve your control. Protect your teams.
Networks of wireless gas detection instruments and monitoring systems can be deployed to give responders and commanders greater visibility and control during operations and overhaul, and to ensure team safety.
Emergency responders can reduce their gas and volatile compound vulnerability by deploying wireless solutions that provide:
Rapidly deployed area-wide multi-gas detection for • measurement of V (the lower explosive limit of a combustible gas, and oxygen, respectively).
Command-centre control that facilitates faster, data-driven • decision-making that helps responders save lives and assets.
Comprehensive data collection and information sharing for • more focused remediation and health tracking.
Biometric and GPS tracking of responders that provides real-• time visibility to the physical status of personnel operating in high-stress and extreme-condition environments.
Emergency responders and EMS professionals must learn to apply their knowledge of the “toxic twins” by taking action to institute policy changes at the departmental level. The toxic and long-term dangers from smoke and HCN is not reserved for HazMat teams only. First-line firefighters must think health and safety first and change perceptions about smoke hazards, especially with those “rough and tough responders” who are often resistant to change. Today, emergency responders must have a mental mindset where they look at a structure fire as a HazMat situation.
