This chapter presents methods for the management and ultimate disposal of laboratory waste that may present chemical hazards, as well as those multihazardous wastes that contain some combination of chemical, radioactive, and biological hazards. The best strategy for managing laboratory waste aims to maximize safety and minimize environmental impact, and considers these objectives from the time of purchase. As suggested in previous chapters, there is a strategic hierarchy for managing chemicals and waste to accomplish these objectives.
The initial responsibility for implementing this hierarchy rests with trained laboratory personnel. These individuals are in the best position to know the chemical and physical properties of the materials they have used or synthesized. They are responsible for evaluating hazards, providing information necessary to make an accurate waste determination, and assisting in the evaluation of appropriate strategies for management, minimization, and disposal.
The overriding principle governing the prudent handling of laboratory waste is that no activity should begin unless a plan for the disposal of nonhazardous and hazardous waste has been formulated. Application of this simple principle ensures that the numerous state and federal regulatory requirements for waste handling are met and avoids unexpected difficulties, such as the generation of a form of waste (e.g., chemical, radioactive, biological) that the institution is not prepared to deal with.
There are four tiers to waste management to reduce its environmental impact: pollution prevention and source reduction; reuse or redistribution of unwanted, surplus materials; treatment, reclamation, and recycling of materials within the waste; and disposal through incineration, treatment, or land burial. The first tier of this strategic hierarchy incorporates the principles of green chemistry (see Chapter 5, section 5.B): pollution prevention and source reduction. Clearly, the best approach to laboratory waste is preventing its generation. Examples include reducing the scale of laboratory operations, reducing the formation of waste during laboratory operations, and substituting nonhazardous or less hazardous chemicals in chemical procedures.
The second strategic tier is to reuse unwanted material, redistribute surplus chemicals, and reduce hazards. Practices that implement this strategy include purchasing only what is needed, keeping chemical inventories to prevent the purchase of duplicates, and reusing excess materials. Sanitary sewer disposal of certain aqueous liquids is considered within this tier, although there are many restrictions (see section 8.B.6.2, below). At this tier it is important for laboratory personnel and environmental health and safety (EHS) staff to work cooperatively to determine the point at which the chemical becomes regulated as a waste and to ensure that requirements are met. In general terms, waste is defined as material that is discarded, is intended to be discarded, or is no longer useful for its intended purpose. This point may occur after the chemical has left the laboratory, however, if the organization has a way to reuse or redistribute the material or to use it in another procedure. Note that regulators may consider a material to be a waste if it is abandoned or is inherently wastelike (e.g., spilled materials). The determination of whether a waste is regulated as hazardous is usually made either by the institution’s EHS staff or by employees of the waste disposal firm.
While the first two tiers are the preferred ways of managing chemical waste, the third strategic tier also provides safety and environmental benefits (see Section 8.B.6). If waste cannot be prevented or minimized, the organization should consider recycling chemicals that can be recovered safely from the waste and the potential for recovering energy from the waste (e.g., using solvent as a fuel). Although some laboratories distill waste solvents for reuse, these strategies are most commonly accomplished by sending the waste to a commercial recycling or reclamation facility or to a fuel blender. These strategies are described later in this chapter.
The fourth and final strategic tier for managing laboratory waste includes incineration, other treatment methods, and land disposal. Decisions within this tier consider the environmental fate of the waste and its constituents and process byproducts after it leaves the institution or firm. As with other tiers, the goal is to minimize risk to health and the environment. Land disposal is the least desirable disposal method. Although modern hazardous waste landfills can contain waste for many decades, there is always a future risk of leaking, contaminated runoff or other harmful releases to the environment. Laboratories that ship chemical waste off-site must address land disposal restrictions and treatability standards, which were put in place to discourage landfilling. Other reasons to consider environmental fate include exhibiting good environmental stewardship, teaching students and employees responsible waste management practices, and maintaining a good public image.
Of course, all laboratories wish to avoid fines and sanctions from federal, state, and local regulators. Because these potential penalties can be significant, this laboratory waste management guidance includes information on laws, regulations, rules, and ordinances that are likely to be most important to people who work in laboratories and support laboratory operations.