Survival Tip 9: Suspicious odors in buildings
By Steven De Lisi
Early one evening, your engine is dispatched to “check for the odor of gas” at a nearby apartment complex. No further details are provided. From prior experience, you know that there are four apartments in every building with a common entranceway and that all units are served by natural gas. Upon arrival, you are met outside of the building by the apartment manager who states that one of the residents had just arrived home and detected the odor of natural gas from a neighboring unit that is unoccupied. There have been past incidents at this location involving problems with appliance pilot lights, so you ask the manager for the key to the apartment in order for you to enter the unit.
Since you anticipate only a minor amount of natural gas being present, you don’t wear your SCBA and you don’t consider shutting off the gas supply to apartments in the building because you don’t want to inconvenience the other tenants. One of the two firefighters is carrying an atmospheric monitor with the capability to detect combustible gases and vapors.
Upon entering the unit, you detect a slight hydrocarbon odor, and the combustible gas sensor of your atmospheric monitor reads 3% Lower Explosive Limit (LEL). Your crew then uses the atmospheric monitor to check all supply lines for the gas stove and hot water heater, but there is no significant increase in the reading near any of the appliances. Puzzled, you begin to check elsewhere in the apartment and soon discover numerous “bug bombs” (also known as total-release pesticide foggers) in each of the three bedrooms of the apartment. The use of these devices far exceeds what should be used in order to be effective. You immediately exit the building, yet despite your quick retreat, your crew has been exposed to enough of the pesticide that the two firefighters with you are now complaining of eye irritation. Despite these physical effects, you consider yourself lucky since you know that use of “bug bombs,” especially in amounts exceeding recommendations of manufacturers have resulted in explosions and fires when these chemicals were ignited by pilot lights from gas-fired appliances. You also know that use of these devices have been known to activate smoke alarms with the potential to expose unsuspecting firefighters. You quickly shut off the gas supply to all apartments, evacuate the building, and call for assistance. In hindsight, you know that use of SCBA would have lessened your exposure, but it is too late for that now.
The manager was unaware that maintenance personnel from the apartment complex had earlier in the day placed the devices in the vacant apartment without first reading the safety precautions. These individuals believed that because of the extent of insect infestation, the recommended dosage would have been insufficient and that more than one of the devices in each bedroom room would be necessary to finish the job!
When called to an incident involving a report of a suspicious odor in a building, the one thing first responders should not do is jump off their apparatus, run inside and sniff around. While some may claim this is the only way to determine the source of the problem, it is also an opportunity for disaster. Always remember that in addition to posing a potential health hazard, suspicious odors could originate from hazardous materials that are potentially flammable.
Sources of suspicious odors can include routine activities such as floor finishing, painting, and plumbing work involving the use of liquid drain cleaners. However, other sources could be leaking containers, such as compressed gas cylinders, or those that contain liquids capable of producing vapors. These containers could be leaking inside of a building, or they could be leaking outside near an air intake for building HVAC systems. Stopping a release from containers may require skills and equipment typically found with hazardous materials teams rather than with first-arriving engine and ladder trucks. For odors known or suspected of being related to the release of natural gas or propane, first responders may be able to operate control valves for these gases, such as those found on metering devices, but only if doing so will not expose them to a dangerous atmosphere. Remember that potentially flammable atmospheres will also require the control of ignition sources and hose lines for the protection of personnel.
Upon arrival at any incident involving a suspicious odor, first responders should always assess the scene, evacuate affected buildings, account for all personnel, and treat anyone who may be symptomatic. These symptoms may be from exposure or they could be psychological. Some individuals may also have evidence of chemical contamination and require decontamination prior to receiving medical care. First responders should also anticipate that any response to investigate a suspicious odor at a large building can quickly escalate into a mass casualty incident.
When conducting your size up of the situation, never forget that the description of an odor is often nothing more than the opinion of the complainant. Don’t bet your life on this subjective assessment of the incident and just assume that their description is correct. Instead, first responders are encouraged to speak with occupants, building owners, and those responsible for maintenance. At a private residence these will likely all be the same person, while for buildings such as apartments, offices, or industrial facilities, there are likely to be three separate parties involved.
Request to know what activities have recently taken place, especially those that may have involved the use of chemicals. These can include maintenance activities or those related to normal work-related operations. Another consideration for questioning is an inventory of materials stored on site.
When using atmospheric monitors to detect the presence of a suspicious odor, these devices may provide a false sense of security. Some atmospheres may also damage the atmospheric monitor rendering it useless. Remember too that there are no “magic meters” that can detect all dangerous atmospheres and first responders who incorrectly assume that zero readings on a “four-gas” atmospheric monitor means they can declare the area safe may be in for an unwelcome surprise later on.
Never believe that first responding companies need to have an answer for all occasions. Instead, some investigations may best be conducted by members of hazardous materials teams or industrial hygienists. In the scenario presented in this article, first responders could have first checked with the apartment maintenance workers to determine the likely source of the odor without ever having to enter the apartment. A few simple questions posed to individuals outside of a building can avoid exposing first responders inside to a potentially dangerous environment.
When dealing with suspicious odors in buildings, be smart, be safe, and remember, everyone goes home!
Discussion Points
- Does your department have a procedure for investigating the source of a suspicious odor in a building? If so, does this procedure include use of a hazardous materials team if an entry is to be made?
- Have first responders in your department ever been exposed to a hazardous material when checking for a “suspicious odor” in a building? If so, what were the outcomes?
Click here for more info on Steven De Lisi’s book, Hazardous Materials Incidents: Surviving the Initial Response.
Steven M. De Lisi is a 26-year veteran of the fire service and is currently Deputy Chief for the Virginia Air National Guard Fire Rescue located at the Richmond International Airport. De Lisi is a Hazardous Materials Specialist and chairman of the Virginia Fire Chiefs Association’s Hazardous Materials Committee. He is also an adjunct instructor for the Virginia Department of Fire Programs and a former member of the NFPA committee on hazardous materials protective clothing. De Lisi began his career in hazardous materials response in 1982 as a member of the HAZMAT team with the Newport News (VA) Fire Department. Since then, he has also served as a Hazardous Materials Officer for the Virginia Department of Emergency Management and in that capacity provided on-scene assistance to first responders involved with hazardous materials incidents in an area that included more than 20 local jurisdictions.
