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Chapter 2 -- Hazardous Waste Determination |
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The initial step in safely managing hazardous waste or potentially hazardous waste is determining if you really need to use the hazardous constituents or whether something that is less hazardous or non-hazardous could be substituted. If you must use a hazardous material, and it in turn becomes a waste material you must determine if it is a "Hazardous Waste". Federal and state regulations contain lists of specific chemicals and chemical characteristics that determine whether a waste is regulated as hazardous or not. This chapter identifies those chemicals which are classified as hazardous and require disposal by the Hazardous Materials Management department. For the purposes of this program, chemicals that should be considered "waste" are those which are spent or can no longer be used. Contaminated chemicals, chemicals in deteriorating containers and any other chemicals which are no longer "used and useful" should be considered waste. Chemicals which can be beneficially reused are not considered waste and should be collected by the LAB WASTE MANAGEMENT OFFICE for redistribution (see Chapter 5).
Listed Hazardous Wastes Federal and state regulations reference several categories of substances which have toxic, carcinogenic, mutagenic, or teratogenic effects in humans or adverse impact on the environment. Currently there are over 700 listed hazardous wastes. Many other chemicals do not appear on these lists but are still considered hazardous (e.g. ethidium bromide and malathion). In general any chemical suspected of having toxic or hazardous properties should be handled by LAB WASTE MANAGEMENT OFFICE. You should refer to Material Safety Data Sheets (MSDS) or other competent reference books such as the Merck Index to make determinations about toxicity. For guidance about whether a waste is hazardous or not, contact the LAB WASTE MANAGEMENT OFFICE staff.
Characteristic Hazardous Wastes Certain wastes which are not specifically listed by name are regulated as hazardous because they exhibit one or more of the following characteristics: ignitability, reactivity, corrosivity, or toxicity. If wastes exhibit any of these characteristics they must be handled as hazardous wastes and disposed of by EM. Material Safety Data Sheets, the manufacturer's container labels, and reference books can be used to identify whether one or more of these characteristics are present. Ignitable: A waste exhibits the ignitable characteristic if it is a liquid with a flash point of less than 140 degrees Fahrenheit (60 degrees Celsius). This includes most non-halogenated solvents such as methanol, acetonitrile, ethanol, gasoline, and ethyl ether. The University also treats as hazardous waste chemicals which are flammable solids, such as magnesium dust, solid naphthalene and nitrocellulose. Corrosive: A waste exhibits the corrosive characteristic if it is a liquid with a pH of less than 2 or more than 12.5 and must be treated as hazardous waste. It cannot be disposed of in the sanitary sewer without first being neutralized (provided it has no other dangerous properties such as toxicity). Examples include hydrochloric acid, photographic chemicals, sodium hydroxide, and corrosive cleaning agents. Dilution of acids or bases with water is not an acceptable practice. It is recommended that acids and bases be neutralized as part of the experimental procedure to reduce the amount of hazardous waste generated. Reactive: A waste exhibits the reactive characteristic if it is unstable, explosive, water or air reactive, a strong oxidizer, an organic peroxide, or contains cyanide or sulfide bearing materials that release toxic gases in contact with acids. Examples include picric acid, potassium metal, metallic picrates, trinitrotoluene, and old ethers. Toxic: A waste exhibits the toxicity characteristic if an extract from the waste contains any of the contaminants in Table 1 at a concentration greater than or equal to the value in that table. The extraction procedure is an EPA-specified test method and costs over $300 to run. In the absence of concentration data, waste containing any of these constituents should be considered hazardous. Many chemical wastes produced at the University are not on this list but are still considered hazardous for our program purposes and can not be disposed of in the sink or regular trash. A more detailed discussion of these materials is found elsewhere in this chapter and Chapter 4. Table 1
Non-Hazardous Wastes As a rule persons who generate chemical wastes should not pour them down the sink or put them in the regular trash unless they are certain that the wastes are non-hazardous to humans or the environment. University personnel should consult Material Safety Data Sheets, the manufacturer's container labels, reference manuals, or call the EM department for guidance on how to dispose of these materials. In general, only non-hazardous solids should be disposed of in the regular trash. Non-hazardous free liquids that are water soluble may be disposed of down the sink. Free liquids that are not water soluble should be referred to the EM department for disposal. Materials that have strong or unpleasant odors should be referred to the EM department for disposal. Chemicals in damaged containers should be placed into appropriate secure containers. If not safe to do so, they should be referred to EM for disposal.
Unknown Wastes/Chemicals All waste materials picked up by the EM department must be completely and accurately identified. Materials that are not identified are referred to as "unknowns." EPA permit regulations prohibit EM from picking up, transporting, or storing unknown waste materials. When an unknown is discovered, an attempt must be made to identify its contents immediately. Usually the contents can be identified by consulting persons who work in the area where the material was used. If this fails to positively identify the material then some elementary analysis on the material must be performed. Elements of this analysis may include: · pH on liquids · Flash point · Reactivity with water (on a very small scale) · Specific gravity · Flammability (on a very small scale) · Water solubility Maintenance of labels, periodic inspections of chemical stocks, and good chemical hygiene practices will prevent the occurrence of unknowns. The University's LAB WASTE MANAGEMENT OFFICE Plan also has specific requirements for labeling chemical containers. |
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