Firehouse Magazine, December 2005
Hazardous Materials
By Jonathan Bastian
This month’s Firehouse theme is hazardous materials. In keeping with the theme, this column will revisit the topic of using thermal imagers at hazmat incidents. While hazmat incidents are not the most common TI applications, they are an important one. A number of fire departments have received TI funding through their hazmat companies, which signals the importance of the technology in hazmat response. Combining this month’s tips with regular practice and use will hone and develop skills at a variety of scenes, not just hazmat incidents.
This month’s column will also ask you, the reader, to become involved with this series in 2006.
Essentials
As with all technology applications, it is important that firefighters remember the normal usage and limitations of thermal imagers. While creativity pushes users to test boundaries and explore new TI applications, creativity must be tempered by reality. The user must have a realistic expectation of what his TI can and cannot do.
- Safety is always paramount, so don’t overlook the basics. TIs are not intrinsically safe, nor is there an explosion-proof model available to the fire service. If the hazmat team is concerned about explosive limits, the TI should probably not enter the hot zone.
- Remember that the interior of the TI is not hermetically sealed. Decontamination efforts will not reach the interior of the TI; if this is a concern, you will have to dispose of the TI as hazardous waste (and bill the responsible party). You may be able to seal the TI in a clear plastic bag (polyethylene seems to work best for the TI) to protect it from the hazardous material and make decontamination easier. Practice protecting your TI prior to actually using it on a hazmat scene.
- A TI generally will help only with liquid and solid hazardous materials. These materials may differ in temperature from the container and the vapor space inside the container. Under the correct conditions, temperature differences enable a TI to help indicate a product level.
- Pressurized gases will not show a product level in a container. However, gases escaping a pressurized system cause an endothermic reaction, potentially making the area of escape colder than the rest of the system. During a search for a gas leak, looking for a cold section in the containment system could help you locate the primary location of the leak.
- Sometimes, a product level will not be visible. Do not fool yourself into seeing a product level that is not really present. Consider the effect of reflections and external heat sources on the container, as well as your knowledge of the material, to help you evaluate whether the indications on the TI are truly product levels. Insulated and double-hulled containers will impede temperature transfer to the container surface, and make it more difficult for your TI to detect a temperature difference and indicate a product level.
- A TI can help locate and track spills of solid and liquid materials. If the spilled material is a different temperature than the ground or water on which it is spilled, and the material stays on the surface, it should be visible to your TI. This can help you locate a spill, track its source and determine the extent of contamination.
Practice Makes Perfect
Tracking product spills and identifying product levels in containers are two common hazmat applications for the TI. You can practice both skills by using materials in and around the firehouse. Pour non-toxic materials on the floor, or in a sink filled with water. Have members use the TI to locate and track the material. You can fill empty containers, or use partially full containers from around the station, to practice determining product levels. As you examine items in the firehouse, you should notice that sometimes you cannot determine a product level. This is not because there is no product, but rather because there is no temperature difference on the container surface for the TI to detect.
Transfer these same skills out into your fire district. While traveling your still district, you should see product levels more frequently because the effects of the sun and weather often create temperature differences within the container.
Final Report
While the TI does not help you remove the hazardous materials at an incident, it can help you locate and isolate the materials. Proper use under the correct conditions can also help firefighters identify the quantities of material they are facing. Regular use around the firehouse as well as on the streets will give firefighters the skill and confidence to use the TI regularly in all types of incidents.
Your Input
This column will take on a new format for much of 2006, a format that will require input from thermal imager users. I would like to take your real-life TI experiences, and share them with the rest of the fire service. What has worked for you, when you thought it would not? What did not work for you, even though you thought it should? What has been your most successful use of a TI, or your greatest disappointment? What do you want to know about your TI, but have not been able to ask?
This column will take your experiences and help analyze them so that all firefighters who read Firehouse can benefit and learn from what happens in your fire company. Send as much information as possible about the incident or situation. Include the make and model of your thermal imager, as well as a way for me to contact you with additional questions. Tell me about your department, as well as the area you serve. And let me know how anonymous you want to be: your situation can be identified by name and FD, by first name and state (“Bill in Wisconsin”), or generically (“a captain on a small career fire department”).
Email your story, experience, frustration or question to me at jonathan_bastian@bullard.com. With your help, this column can address the information you specifically want to know and help you educate your brothers and sisters in the fire service. Be safe.
By setting up a series of containers in the firehouse, firefighters can practice viewing product levels of different materials and temperatures. Depending on the conditions, a product line may not be visible with the TI.
Materials that float or stay on the surface beneath them can be identified and tracked with a TI. Here, oil on water is easy to identify by the temperature differences. Note that materials miscible with water will not be traceable with the TI.
The compressed gas escaping from this cylinder has made the valve stem much colder than the other objects in the image. The endothermic reaction of escaping gas can help firefighters locate a leak in a compressed gas system.