Responding to incidents involving oxidizers takes awareness and planning
Responders are called to an ever-increasing number of diverse types of incidents these days, which makes it difficult to stay prepared and practiced for all the possibilities we may encounter. That especially applies to responding to hazardous materials incidents. So, if you are not on a hazardous materials response team how often do you review and refresh your knowledge on the classes of hazardous materials we encounter in the course of doing the job? Sure, it’s important to keep sharp on fire operations but those calls that we don’t respond to very often can really hurt us or worse.
Recent events like the devastating explosion in Beirut, Lebanon give us pause to think about those firefighters who were just doing their jobs and, boom, tragedy happens. This incident makes me think about the impact that oxidizers can have on fire and what they can do when they mix with incompatible material such as organic compounds.
Guidelines for safely handling incidents involving oxidizers
A good definition of oxidizers can be found in NFPA 400, Hazardous Materials Code, 2022 edition. Oxidizers are: “Any solid or liquid material that readily yields oxygen or other oxidizing gas or that readily reacts to promote or initiate combustion of combustible materials and that can, under some circumstances, undergo a vigorous self-sustained decomposition due to contamination or heat exposure.”
Furthermore, oxidizers are broken down into four classes from Class 1, “…does not moderately increase the burning rate…” to Class 4, “…can undergo an explosive reaction due to contamination or exposure to thermal or physical shock…”
NFPA 400 provides a wealth of information and can be a helpful resource. Annex E covers Properties and Uses of Ammonium Nitrate and Fire-Fighting Procedures and is included for informational purposes only, but can be a helpful guide when developing department standard operating procedures for handling events that include oxidizers. An additionally helpful chapter is Annex I, Emergency Response Guideline. This chapter speaks to the emergency response training requirements for handling hazardous materials emergencies found in OSHA 29 CFR 1910.120, including the levels of awareness, operations, technician, specialist and incident commander also explained in NFPA 470 Hazardous Materials/Weapons of Mass Destruction Standard for Responders, 2022 edition.
Sure, the larger cities have hazmat units to handle all that, but many of our more rural departments may rely on a regional response team who is several miles away or some teams may have to assemble at the station before they respond to your incident, which takes time. Some departments don’t even have that luxury, so what do we do?
Oxidizer identification and pre-planning matter
One of the first things that is necessary is identification. Identifying what oxidizers look like, how they are identified, and where they exist in your response area is an important step. You can do that by reviewing what the container markings look like and by getting out into your response area on pre-planning trips to learn about what and where they are used and stored. In the case of rail transport, what is traveling through your jurisdiction? I would recommend connecting with the rail transport organizations that have stock rolling through your jurisdiction. Pre-planning is a very important part of keeping your team situationally aware and prepared for an incident at a specific location.
When arriving on-scene, the Emergency Responder Guide (ERG) can help
Another very useful quick guide is the Emergency Response Guide (ERG). This guidebook created by the US Department of Transportation, Pipeline and Hazardous Materials Safety Administration, is a guide designed to provide important information to responders in the first minutes of an incident. The guide is set up with separately colored pages that provide important information about material identification, classification, attributable hazards, and response and evacuation guidelines. For example, information on general oxidizers can be found in Guide #140. In this yellow page portion of the document, you will find information on potential hazards such as fire or health, what considerations to make on protective clothing, evacuation measures to consider, emergency response actions in the case of spill or fire, and first aid measures to take if exposed. The information found on this guide page and others can be reviewed with your team in a quick drill format and be a useful refresher on dealing with oxidizers.
Another example of what can happen when oxidizers are exposed to heat is an incident that occurred May 28, 2013 in Rosedale, Maryland when a three-axle roll-off straight truck entered a grade level train crossing and was struck by an oncoming freight train. Fifteen of the train cars derailed with three of the cars carrying hazardous materials. Two of the cars spilled their contents, including an oxidizer and an organic acid, resulting in fire. The heat from the fire caused the oxidizer to explode early into the fire. Fortunately, the responding units had not arrived, or the results might have been tragic.
Additional information about this accident may be found in the investigation report, which can be accessed at the NTSB website under report number NTSB/HAR-14/02.
Slow down and be cautious
So especially when responding to bulk storage units or large capacity transportation rail cars, use the utmost caution until you can verify the identity of the contents contained within. Based on the reports of the first due units trained to identify railcars carrying chemicals such as oxidizers, they can alert other incoming units and help initiate the appropriate action plan.
Remember when responding into a potential hazardous materials incident: slow down and take some time to look for signs that indicate what you may be dealing with before getting into a potentially career ending event. Take the time to refresh on the basic types of hazardous materials and what their characteristics are. Especially with oxidizers, remember that when exposed to other types of organic compound they can react explosively and when exposed to heat they can explode. It’s all part of situational awareness. Be aware and be safe.