Hazard Class Descriptions

Nine hazard classes have been identified for describing and grouping hazardous materials. This information may prove useful when advising others on how to properly identify and classify fuels and other hazardous materials. 

1) Flammable solids. Solids, other than those classified as explosives, which are readily combustible, or may contribute to fire through friction during transport 

2) Substances liable to spontaneous combustion. Substances which are susceptible to spontaneous heating during transport substances which heat up in contact with the air and catch fire 

3) Substances which emit flammable gases when in contact with water 

1) Substances which may not combust themselves, but by yielding oxygen, may contribute to the combustion of other materials. 

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CAS number UN number Classification Hazard class Description ... 

Hazard Class A series of nine descriptive terms that have been established by the UN Committee of Experts to categorize the hazardous nature of chemical, physical, and biological materials. These categories are flammable liquids, flammable solids, explosives, gases, oxidizers, radioactive materials, corrosives, poisonous and infectious substances, and dangerous substances. 

The manifest must contain the name, address, telephone number and EPA identification number of the generator, transporter and designated receiving facility, and description, quantity, hazardous waste ID number, and hazard class of waste. 

The proper selection of chemical shipping descriptions, and the determination of the hazard class, require chemical expertise and familiarity with DOT definitions of such classes, which are provided in Part 173 of the hazardous materials regulations. In some cases such definitions are sufficiendy... 

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). 

This handbook is designed for people who have to find data quickly in emergency situations. Data are provided in the form of MSDSs including chemical name and synonyms. DOT hazard class andguide number, physical description, chemical properties, health hazards, first aid procedures, and hazards associated with fire, reactivity, corrosivity, and radioactivity. 

Because of the descriptive nature of the flammable solid and oxidizer definitions it is difficult to determine if a material falls within the definition of either hazard class. In efforts to make both definitions more specific and to provide tests which would allow appropriate classification, the Materials Transportation Bureau has requested comments on new definitions and proposed test methods for the flammable solid and oxidizer hazard classes. The reader should become aware of these test methods definitions since they could become part of the regulatory framework. In addition, the test methods could serve as guidance, even at present, for decisions involved in classifying a material as a flammable solid or as an oxidizer. 

Carbon tetrachloride is regulated for shipments by air or water as an ORM-A material, as indicated by the letters A and W on Column 1 of the Hazardous Materials Table. This chemical also has on the table the letter E on column 1. As with all hazardous substances, the reportable quantity (RQ) for that material follows the name of the substance, 5,000 pounds in this case. Thus, if more than 5,000 pounds of carbon tetrachloride are shipped in one package, or in one transport vehicle if not packaged, carbon tetrachloride is regulated, as a hazardous substance, by all modes of transportation. However, the hazard class remains ORM-A and the regulatory requirements are met by the addition of the letter RQ to the proper shipping description. 

Dangerous Goods List contains relevant information on the listed hazardous materials including the UN number, chemical name and description, hazard class, packing group(s), label(s), special provisions, exemptions, and limited quantities... 

Storage class Description RID/ADR Hazard characteristic in accordance with 3 a) of German chemicals law Relevant hazard warning (R phrases) ... 

Failure to include a hazard class/ division number in the shipping description 172.202 ... 

Hazardous Material Description Enter the proper shipping name, technical or trade name, hazard class or division, ID number, packing group, and amount of material released. All of this information, except the amount of material released, can be found on the shipping papers that accompany the shipment, 172.202. When indicating the amount of material released, include units of measurements (examples 115 gallons, 69 tons). 

Also referred to as the Uniform Hazardous Waste Manifest (UHWM). If all DOT requirements, i.e., the basic description (proper shipping name, hazard class/division, ID No., and packing group) are entered on the UHWM, the manifest may he used as a shipping paper per 49 CFR 172.205. 

Over the past few years a better understanding of lasers has resulted in an evolution of classification systems for lasers. Before 2002 the older system of classification used Roman numerals with the most hazardous class being Class IV (see Special Topic 7.3.3.1 Old Laser Classification). As experience with lasers grew, the classification system was updated to include new defining specifications. Beginning in 2002 a newly revised classification system was phased in and was fully implemented in 2007. It is based on International Electrotechnical Commission (lEC) Standard 60825-1/ANSI Z136.1—2007 that separates lasers into four classes. Class 1 is the least hazardous, Class 4 is the most hazardous, and there are new subclasses." The classification of lasers is dependent on the dose of radiation that can be received from a laser. A brief description of these laser classes is presented in Table 7.3.3.2. 

Shipping Papers DOT regulations require that a shipping order, bill of lading, manifest or other document used to initiate a shipment must describe any hazardous material offered for shipment. The description must include the name of the material, the DOT hazard class and division, the... 

US. Department of transportation description (including proper shipping name, hazard class. UN ID number, and any additional Information)... 

Sym- bols Hazardous material descriptions and proper tipping names Hazard class or Division Identi- fication numbers PC Labe codes Special provisions Excep- tions Non bulk Bulk Passenger aircrafl/rail Cargo aircraft only Loca- tion Other... 

Item 9. U.S. DOT Description (Including Proper Shipping Name, Hazard Class or Division, Identification Number, and Packing Group)... 

Item 2 7. U.S. D. O. T. Description Including Proper Shipping Name, Hazardous Class, and ID Number (UN/NA)... 

The European Standard EN 599-1 (1996) provides a good description of testing requirements according to hazard class. Similar descriptions may be found which are used on other continents, for example, the American Wood Preservers Association Standards (AWPA). Brief descriptions of test types are given below ... 

Likewise, the evaluation of each safety plan provides further data essential to establishing a hazard rating for a laboratory. As a part of the safety plan review process, each PI must complete the laboratory process description form, modeled after 29CFR1910.1450(e) (see Figures 1,2), and submit an up to date copy of the laboratory chemical inventory to facilitate the ranking of labs into a hazard class. This ranking is a subjective assessment of the degree of hazard to personnel and the environment presented by the procedures and chemicals in the lab. 

DOE recommends the use of a systematic approach to training, in which the content of training is commensurate with the potential hazards, exposures, worker roles and responsibilities, and requirements of the project (see Eigure 8-1) [1]. The description of this systematic approach sounds like a great idea. However, in some cases the execution of the systematic approach is difficult to attain. In general, training classes aim content and level to reach at least 80 percent of attendees. 

There are various fire classes that require different sprinkler designs. The detailed descriptions of these classes and sprinkler specifications are given in NFPA 13.12 An average chemical plant is classified as an ordinary hazard (Group 3) area. Various sprinkler specifications for this type of area are given in Table 7-7. 

UN or IX). No. Proper Shipping Name/Description Haz. Class Sub. Risk Hazard Label Pack Grp. 

Another important feature of the classification system for nuclear fuel-cycle wastes in the United States is the definition of low-level waste only by exclusion there is no definition of what low-level waste is, only a definition of what it is not. As a result, in contrast to the earliest descriptions of low-level waste prior to the establishment of definitions in law, this class is not restricted to waste that contains relatively low concentrations of radionuclides compared with high-level waste. Rather, low-level waste can range from virtually innocuous to highly hazardous over long time frames. 

Given the qualitative definitions of the three waste classes, the boundaries of the waste classes would be quantified based on explicit descriptions of how the definitions are related to risk. The boundaries would be expressed in terms of limits on amounts (concentrations) of individual hazardous substances, with specified rules for how to classify waste that contains mixtures of hazardous substances, such as the sum-of-fractions rule for mixtures of substances that induce stochastic effects. Specifically, waste would be classified as exempt if the risk that arises from disposal in a municipal/industrial landfill for nonhazardous waste does not exceed negligible (de minimis) levels. Use of a negligible risk to quantify limits on concentrations of hazardous substances in exempt waste is appropriate because the waste would be managed in all respects as if it were nonhazardous. Nonexempt waste would be classified as low-hazard if the risk that arises from disposal in a dedicated near-surface facility for hazardous wastes does not exceed acceptable (barely tolerable) levels. An essential condition of the definitions of exempt and low-hazard waste is that an acceptable (barely tolerable) risk must be substantially greater than a negligible risk. Waste would be classified as high-hazard if it would pose an unacceptable (de manifestis) risk when placed in a dedicated near-surface facility for hazardous wastes. 

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