Focus on Hazmat

Someone once said that a hazardous material or “hazmat” is anything that sits quietly in its box until something goes wrong, then raises up and bites you. This is not a bad street definition. Nowadays people tend to think of hazardous materials in terms of fuels and chemicals – commodities that are shipped in bulk quantities. These can and certainly do rise up and bite at inopportune moments.

Each regulatory agency establishes its own list of hazardous materials (known in Canada as “Dangerous Goods”). Differences in lists and requirements for packaging lead to a great deal of confusion. Worse, they make problems for hazmat responders. A case in point is the part of CFR Title 49 Part 171.8 which specifies “ORM-D,” a.k.a. “subpart D.”

ORM-D is a marking for mail or shipping in the United States that identifies regulated materials for domestic transport only. Packages bearing this mark contain hazmats in limited quantity that presents a limited hazard during transportation, due to its form, quantity and packaging.

 Consumer commodity is defined as a hazardous material that is packaged and distributed in a quantity and form intended or suitable for retail sale and designed for consumption by individuals for their personal care or household use purposes. This term can also include certain drugs or medicines.

Items classified as ORM-D include aerosol cans, perfumes, photo chemicals, soldering flux, lighters and drain openers.

The Code of Federal Regulations (CFR) Title 49 Part 171.8 defines a consumer commodity and other items with exceptions listed in the 172.101 table. Any item of limited quantity and conforming to the definition of consumer commodity may be marked and sent ORM-D. Weight and volume restrictions for all ORM-D packages vary by hazard class. For example, a gallon of Class 3 flammable liquid PGII cannot be reclassified as ORM-D because it exceeds the limited quantity volume. However, a gallon of a Class 6, PGIII material is within the volume criteria for a limited quantity. That gallon can be labeled as an ORM-D if it meets the definition of a substance that can be converted from a limited quantity to an ORM-D.

It is impossible to have an ORM-D that does not fit the criteria for a limited quantity. First, an item is determined to be a limited quantity. Then it is determined if it can be reclassified further to become an ORM-D. If the item can be reclassified, the proper shipping name is usually, but not always, “consumer commodity,” as found in the 172.101 table. Other proper shipping names used for ORM-D material are “cartridges small arms” and “cartridges power device.” These products will no longer fall under one of the nine hazard classes, either. The “hazard class or division” is now defined as “ORM-D.”

Material marked ORM-D and shipped by surface transportation does not require hazardous shipping papers, simply an ORM-D and proper shipping name marking on the box. This marking can either be in the form of an ORM-D sticker or written by hand. If written by hand, the letters “ORM-D” must be enclosed by a rectangle. This means a person can purchase a can of a wellknown spray-on lubricant, that has only the barest warning about flammability because it is classed as an ORM-D. If a person purchases a whole gallon of the same lubricant the container has warnings printed all over it and a material safety data sheet is available. In either container, the product will burn quite readily, labeling requirements notwithstanding. In fact, there is an added risk posed by the pressurized aerosol can. Even at ambient temperature, these containers are under pressure due to the propellant gas which is often un-odorized propane or butane. In the event of a fire, they are very likely to burst, releasing a mixture of the flammable product and the propellant. That is not a good thing to have happen on a busy highway or in a residential district. To demonstrate this problem drop one of these aerosol cans into a trash incinerator, but leave post haste.

When transported by air, ORM-D shipments require an ORMD-AIR marking and full hazardous shipping papers.

This is only one example of the unintended glitches in the current hazmat regulations. While these were written and promulgated with the best of intentions, they can sometimes cause more problems than they solve. The prudent response officer will find it expedient to ask a number of questions, including:

• What material is involved? Unfortunately the driver or train crew may not know the answer, particularly in the case of an “ORM-D,” but it is important information. If it can be obtained from the shipper or other source, it will help to determine response methodology.

• Is it the only material involved or is it a mixed load? Many ordinary products are combustible. Even the aluminum and/or magnesium used in auto making can burn. When ignited, these metals (particularly magnesium) burn at extremely high temperatures and are exceedingly difficult to extinguish.

• What is the primary hazard? Is it possible that it is nothing but a hot object? A load of road oil (asphalt) is not in itself hazardous, but when heated to a temperature exceeding 3,000 degrees Fahrenheit, it can cause severe burns and possibly ignite nearby combustibles. The hazard lies in the high temperature, not in the composition or chemical make up of the material involved. The remediation protocol in such a case is to prevent ignition and wait until the material cools. This can be hastened by the use of water fog. Once the material cools, it can simply be picked up and hauled away.

The same thing holds true for the opposite end of the spectrum – cryogenic gasses. Oxygen, nitrogen and carbon dioxide are all normal atmospheric components and are essential to life. Yet, they are shipped as hazmats. The hazard is found not in the structure or composition of the material but in the low temperatures and high pressures used to contain them. Boyle’s law states that all gasses change temperature with changes in pressure. A sudden release of pressure results in an expansion and a concurrent cooling of the gas and its surroundings. This cooling effect is known as “auto-refrigeration.” All gasses exhibit this phenomenon and it is the basis of modern refrigeration systems. While the effect is not as extreme in the case of compressed gasses like chlorine and LPG as it is in the cryogenic gasses, it is enough to freeze flesh and cause severe frostbite.

• Are there secondary hazards caused by reactions of the spilled product? Chemicals react with their environment and elevated temperatures usually accelerate chemical reactions. The result is that the responder is confronted by something not part of the shipment, and he has no clue to its identity other than evidence present at the site. A good example of this is domestic scouring powder which carries a label warning against mixing with household bleach. The warning does not specify that the reaction results in a highly toxic gas. Pouring bleach into the black-water holding tank of a recreational vehicle nearly cost the owner his life. It reacted with the urea present in the waste water and generated enough gas to make the atmosphere toxic.

Nitric acid reacts with red metals such as copper and brass to evolve nitrogen dioxide, a highly toxic reddish brown gas. This reaction is often seen when nitric acid, and occasionally other nitrogenous materials react with copper plumbing or electrical wiring. Again, a secondary hazard not associated with the original shipment.

 Nitric acid exhibits different chemical properties reactions at various concentrations. At concentrations below 37 percent nitric acid reacts like most other mineral acids. It is used to etch metals, including copper, which yields a blue solution of copper nitrate. However, above 37 percent it also exhibits the properties of an oxidizing agent. It can ignite organic materials such as sawdust or cause the evolution of nitrogen dioxide. This explains why concentrated nitric acid is shipped with two placards, “oxidizer” and “corrosive.” It also explains why sawdust or any other organic sorbent should never be used to contain nitric acid.

Polymers, i.e. plastics, are particularly bad about secondary or “side” reactions. When they get too hot, they tend to decompose. The products of this decomposition are, more often than not, highly toxic. This was demonstrated years ago when an underground vault in New York City owned by the telephone company burned. The wiring was covered in polyvinyl insulation. When this wiring overheated and burned, large quantities of HCL, CO and other gases, mostly toxic, were released. A number of very serious injuries resulted, some permanently disabling the victims. Most injuries resulted from breathing the contaminated atmosphere.

In the United States, untold millions of miles of electrical wire is covered in vinyl plastics. It is found in homes, commercial buildings, airplanes, trains and highway vehicles. It is all hazardous in case of fire or severe electrical overload but this is not mentioned on the shipping papers. No warning placards pertains to them. It is prudent to assume that these are always present and burning until it is proven otherwise.

The fire department responds to a hazmat transportation incident 20 miles south of West Nowhere. The available documentation and operator information, if any, has been collected. Decide what to do. Of course, the surroundings play a big part in that decision. The response in a congested residential area is quite different from the same incident in a remote desert area 20 miles from the nearest habitation. The shipper and/or manufacturer, contacted through CHEMTREC (CHEMical TRansportation Emergency Center) is an ideal source for information. These people will be the most knowledgeable about the problem, but they may be a long way from the incident. Another excellent resource is the local education system. A knowledgeable high school chemistry teacher or, better yet, a professor at a local community college or university will be familiar with chemicals used in or transported through the community. Make contact with this individual and build a relationship, particularly as a mentor of a response agency in a smaller community utilizing volunteer departments. Water treatment plant operators are another good source of information, especially regarding chemicals they use daily. Local medical providers should be consulted and advised of any injuries and/or exposures. These people can advise responders as to the degree of exposure and what first aid measures to undertake.

The Fire Protection Guide To Hazardous Materials (NFPA) is an excellent information source regarding secondary chemical reactions and should be in every response organization’s library. Common knowledge or “street chemistry” is a valuable asset when dealing with hazmat incidents. For instance, anhydrous ammonia (NH3) reacts with hydrogen chloride (HCl) or hydrochloric acid (an aqueous solution of HCl). In doing so, it produces voluminous quantities of white smoke composed of ammonium chloride (NH4Cl). A commercial grade of hydrochloric acid commonly used for cleaning masonry and metals, it is marketed as “muriatic” acid. When burning, its smoke is fairly innocuous in moderate quantities. However, the amount produced by even a small leak can be deceiving. Reddish-brown fumes emanating from a pile up indicate poisonous nitrogen dioxide, and it is time to either leave the area or don SCBA (self-contained breathing apparatus). A high pitched scream emanating from a venting safety valve on an LPG tank rising internal pressure. A rupture followed by an explosion is likely imminent.

Take warning signs like these seriously. Labels, placards and shipping papers are not fool-proof. The possibility exists that a shipment is misrepresented, by accident or design. Perhaps someone failed to attach a label or install a placard. Perhaps they are recycling a container and failed to remove the markings from the previous contents. Of course the possibility exists that the contents of a damaged and/or leaking container may instigate reactions releasing dangerous materials that are not even contemplated. Whatever the case, one should go with what is happening at the site. Follow the old adage, “If you don’t know, don’t go – it may blow.”

You may be accused of over reacting. So what? As David White’s column on Page 4 says, only the paranoid survive. The important thing to worry about is being around to get a chance to look silly again tomorrow.