The “dangerous evolution of heat” sounds like a climate change issue and not something hazardous materials transporters need to worry about in their day-to-day operations. But, here is a recent example of why you need to take this concept into account if you are in the business of transporting hazardous materials that are regulated by the U.S. Department of Transportation’s (DOT) Pipeline and Hazardous Material’s Safety Administration (PHMSA).
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PHMSA officials were recently asked to address the definition of the “dangerous evolution of heat” under the hazardous materials regulations (HMR).
According to the PHMSA, the HMR do not specifically define “dangerous evolution of heat,” but it is described as an “amount of heat sufficient to be dangerous to packaging or personal safety to include the charring of packaging, the melting of packaging, the scorching of packaging, or other evidence” in a number of examples in the HMR. Let’s take a look at six of these examples, four of which concern the transportation of batteries.
Note. Incidents that occur “during the transportation of hazardous materials” include incidents that occur in the course of performing pre-transportation functions, which include, in part, loading, blocking or securing a package or container.
- Transporting batteries on aircraft
In 49 CFR 171.15, the HMR lists the hazardous materials incidents that require immediate notice by telephone (i.e., as soon as practical, but no later than 12 hours) to the National Response Center. These reportable incidents include if a fire, violent rupture, explosion, or dangerous evolution of heat occurs as a direct result of a battery or battery-powered device during transportation by aircraft.
- Detailed report required
49 CFR 171.16(a)(5) outlines when a detailed Hazardous Materials Incident Report is required to be sent to the DOT within 30 days of the discovery of the incident. These reports are required any time there is a dangerous evolution of heat during transport of batteries or battery-powered devices (including loading, unloading and temporary storage). Note that this requirement is not limited to transportation by aircraft but apply to all modes of transportation.
- Special Provision 130 for dry batteries
Special Provision 130 under 49 CFR 172.102(c) refers to the transportation of dry batteries (i.e., batteries, dry, sealed, n.o.s.) that are not covered by another entry in the hazardous materials table at 49 CFR 172.101. Under Special Provision 130, these batteries are exempt from the requirements related to materials on the hazardous materials table with some exceptions. Three of the exceptions concern the dangerous evolution of heat regarding dry batteries:
- Dry batteries that cause a dangerous evolution of heat during transportation by aircraft are subject to the immediate incident reporting under 49 CFR 171.15.
- Dry batteries or battery-powered devices that cause a dangerous evolution of heat during transport by any mode of transportation are subject to the detailed Hazardous Materials Incident Report requirements of 49 CFR 171.16.
- Dry batteries and battery-powered devices must be prepared and packaged for transport in a manner that prevents a dangerous evolution of heat.
- Wet batteries
49 CFR 173.159 contains the nonbulk packaging requirements for shipping wet batteries (i.e., electric storage batteries that contain electrolyte acid or alkaline corrosive battery fluid). These requirements include that the batteries be packaged so as to avoid a dangerous evolution of heat. 49 CFR 173.159(a) contains the conditions for exceptions from the nonbulk packaging requirements of 49 CFR 173.159 for nonspillable wet batteries. However, the incident requirements for aircraft and the report requirements for all modes of transportation related to the dangerous evolution of heat still apply to nonspillable wet batteries.
- Forbidden materials and packages
49 CFR 173.21 lists materials or packages that are not allowed to be transported unless otherwise indicated in the HMR. These forbidden materials and packages include:
- Electrical devices, such as batteries and battery-powered devices that are likely to create sparks or generate a dangerous evolution of heat, unless they are packaged in a manner to preclude such and occurrence;
- A material in the same packaging, freight container, or overpack with another material, the mixing of which is likely to cause, in part, a dangerous evolution of heat; and
- A package that contains a material that is likely to self-decompose at a temperature of 122 ºF or less, or polymerize at a temperature of 130 ºF or less, with a dangerous evolution of heat or gas when decomposing or polymerizing unless the material is stabilized to preclude such evolution.
- Mixed contents
Under 49 CFR 173.24, hazardous materials may not be packed or mixed together in the same outer packaging with other hazardous or nonhazardous materials if the materials are capable of reacting dangerously with each other and causing, in part, a dangerous evolution of heat.