Class 7 placards

General placarding requirements are described in 49 CFR 172.504. Placards are required at each end and on each side of a transport vehicle, bulk package, or freight container for hazardous materials in accordance with Table 1 of this section. Radioactive materials require Class 7 placards if package dose rates merit a Yellow-111 label, and for exclusive use LSA and SCO shipments. Note that placards for a highway route controlled quantity are of a different design than standard Class 7 placards. 

Shipment of hydrazine solutions is regulated in the United States by the Department of Transportation (DOT) which classifies all aqueous solutions between 64.4 and 37% N2H4 as "Corrosive" materials with a subsidiary risk of "Poison". Hydrazine has been identified by both the Environmental Protection Agency and the DOT as a hazardous material and has been assigned a reportable quantity (RQ) of 0.450 kg (1 lb) if spilled. Dmms for the shipment of these solutions must bear both the DOT specification "Corrosive" and "Poison" labels in association with the markings "RQ Hydrazine Aqueous Solution UN 2030." Aqueous solutions of 37% concentration or less are a hazard Class 6.1, UN 3293, Packing Group III and require "Keep Away From Food" placards and labels. 

Fig. 2. Placard signifying the presence of a flammable gas. The numeral in the lower corner represents the primary ha2ard class of the material in the...

The acid may be shipped in tank cars, tank tmcks, iso-tainers or dmms via common carrier (40). The shipping ha2ard class is Corrosive Material, the DOT labels and placards required are Corrosive and Poison. The UN number is 1754. When iron content and color are not of concern, the acid may be stored and shipped in steel equipment. The iron content is generally 25—50 ppm and the color is pale yellow to amber. 

UN Hazard Classes and Divisions — The hazard class of a material is indicated either by its class (or division) number, or its class name. For a placard corresponding to the primary hazard class of a material, the hazard class or division number must be displayed in the lower comer of the placard. The UN (United Nations) hazard classes are as follows ... 

The categories of liquids are further subdivided into classes according to the flash point plus the boiling point of certain liquids. These divisions are summarized in Table 8, which shows that flammable liquids fall into Class 1, and combustible liquids into Classes 2 and 3. The products that are at the low end (100°F) of the Class 2 combustible-liquid group might be thought of as borderline cases. These could act very much like flammable liquids if atmospheric temperatures were in die same range. It is not a common industry practice to identify either stationary or portable (mobile) liquid containers by the class of liquid it contains. The usual practice is to label either "flammable" or "combustible" and include the required U.S. Department of Transportation placard. 

Substances which fall into these classes are labelled and placarded using the class labels which are shown in Figure 8.1. 

Fig. 3. Illustration of an identification number on a placard for acetone. The numeral in the lower comer represents the primary hazard class of the material.

Warning labels aid in the identification of chemical hazards during shipment. Under regulations of the DOT, chemicals that are transported in the United States must carry labels based on the UN classification. DOT placards or labels are diamond shaped with a digit imprinted on the bottom corner that identifies the UN hazard class (1 to 9). The hazard is identified more specifically in printed words placed along the horizontal axis of the diamond. Color coding and a pictorial art description of the hazard supplement the identification of hazardous material on the label the artwork appears in the top corner of the diamond (Figure 1-6, A). 

Addresses HM-181 requirements, hazard class recognition, DOT table of hazardous materials, placards, marking and labeling, and packaging. 

The class number on a CORROSIVE placard must be white, and on a COMBUSTIBLE placard with a white bottom as prescribed by 172.332(c)(4), the class number must be red or black. 

Specifying one s label and/or placard is a fairly simple matter once the proper shipping name has been determined. If the label manufacturer has any difficulty at all in day to day operations, it is with those companies who have not properly identified the hazard class for their particular compound. In the waste area, it often appears that the proper shipping name. Hazardous Waste, Liquid, n.o.s. has become a convenient catch-all for materials where the hazards are not known. Proper testing of the material is essential for it is only in that manner one may be certain what the hazard class really is. 

A language barrier should not stand in the way of hazard communication. In some ways, a precedent has already been set vis-a-vis the four-digit placard. This placard, without the use of words, communicates the symbol, color and class number. The four-digit UN number simply identifies the specific commodity. Is the white flame on a red background with Class Number 3 any less a Flammable Liquid label than with the use of those words Or, is the green label with the white cylinder and Class Number 2 any less a Non-Flammable Gas There will be those who will object to the additional training necessary in a world without words. It is suggested that such a step will not be as difficult as it may appear, and further, it will promote safety and economic benefits in both international and domestic trade. 

A freight container, motor vehicle, or rail car, which contains two or more classes of materials requiring different placards as specified in Table 14.3, may be placarded DANGEROUS in place of the separate placarding specified for each of those classes of material specified in Table 14.3. When 5,000 pounds... 

An EXPLOSIVES B placard is not required if the freight container, motor vehicle, or rail car contains class A explosives and is placarded EXPLOSIVES A as required. 

A FLAMMABLE SOLID "W" placard isrequiredonly when the DANGEROUS WHEN WET label is specified in 172.101 for a material classed as a flammable solid. 

A COMBUSTIBLE placard is required only when a material classed as a combustible liquid is transported in a packaging having a rated capacity of more than 110 gallons, a cargo tank, or a tank car. 

It should be remembered, however, that these placarding exceptions relate only to materials found in Table 14.3 but not Table 14.2 (Class A and B explosives. Poison A, specified Flammable solids, and specified Radioactive materials). Placards must be applied for each material in Table 14.2... 

Each hazard class has associated placards and labels identifying the hazards of the class during transportation. Each hazard class and associated placard has a color, which indicates a particular hazard. Hazardous materials may have more than one hazard. It is important to note that the placard on a transport vehicle depicts only the most severe hazard of a material as determined by DOT hazard class definitions. When a material has more than one hazard, the DOT prioritizes the hazard that will be placarded. These hazards are listed by the DOT in 49 CFR 173.2a (see Figure 1.7) to determine which hazard will be assigned to a particular material when the material has multiple hazards. 

Almost every hazardous material has more than one hazard. As an emergency responder, you must be familiar with other potential, and often hidden, hazards that chemicals may present. Figure 1.8 shows the potential hidden hazards of the nine hazard classes. Across the top of the chart are all the potential hazards a chemical could have that would affect emergency responders. Down the left side are all of the colors representing the UN/DOT hazard classes. An X is used to identify the DOT hazard designated for the material and the color of the placard, which will be on the shipment. An asterisk ( ) is used to identify aU of the other potential hazards of the materials. That does not mean that a particular chemical has all of the hazards, but until you are able to obtain additional information, precautions must be taken for each. For example, some corrosive materials are classified as oxidizers, such as perchloric acid above 50% concentration. Perchloric acid above 50% concentration... 

Do not focns only on the hazard depicted by the placard. Thoroughly examine all hazardons materials enconntered to determine all physical and chemical characteristics and hazards associated with the chemical. An incident occnrred in Kansas City, Missonri, in which six firefighters were killed fighting a fire involving commercial-grade ammoninm nitrate, a 1.5 Blasting Agent nnder the DOT hazard class... 

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