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Facts About Hazardous Waste for a Laboratory

Hazardous wastes are common in most laboratory settings. Everyone working with hazardous wastes in a laboratory or elsewhere should be aware of basic safety information and the specific dangers of the chemicals being handled.

  1. MSDS and CAS

    • For every chemical there is a corresponding Material Safety Data Sheet and specific Chemical Abstract Service number. CAS numbers allow for rapid access of a chemical's hazard information from a database, which is organized on an MSDS. Each MSDS contains standard information about a chemical's safety risks, specific traits like reactivity and flammability, measures for first aid upon exposure, and other relevant information if available. Always read an MSDS and be familiar with the hazards of a chemical before working with it. Otherwise, you may pose a risk to yourself and others in the laboratory.

    Hazard Categories

    • The primary categories for safety as found on an MSDS are ratings of health risk, flammability, reactivity and contact danger. Health risks may be the toxicity or poisonous nature of a chemical, while contact danger refers to how corrosive a substance is. Flammability rates how likely a chemical is to catch fire, and will include the flash-point temperature for spontaneous combustion. Finally, reactivity measures how vigorously and violently chemical reactions progress for a substance. More reactive chemicals produce greater amounts of energy and can cause fires or explosions.

    Storage

    • Hazardous waste must be properly stored to avoid accidental release and reactions. Separate storage cabinets should be used for different hazard categories, as many chemicals create strong reactions if mixed. For instance, some chemicals will react readily with water and thus should be stored separately from aqueous solutions.

    Personal Protective Equipment

    • Certain kinds of wastes require a range of personal protective equipment, or PPE. For many substances, disposable nitrile gloves, vented splash goggles, close-toed shoes and a lab coat are sufficient protection. More dangerous wastes, however, require a lab technician to take more rigorous precautions. Respirator masks may be necessary for chemicals that generate fumes or noxious odors, with a filter cartridge appropriate for the fumes. Standard HEPA (high-efficiency particulate air) acid/gas cartridges protect against a range of gases, but always check an MSDS to be sure about safety equipment. Most importantly, personal protective equipment must be fit-checked to be sure it provides the safety it is supposed to. A respirator mask that doesn't form a seal over the face will not protect the user, and may increase dangers by providing a false sense of confidence.

    Disposal

    • Eventually, all hazardous waste in a laboratory must either be neutralized or disposed of properly. Some chemicals can be pH-balanced and evaporated into harmless salts, like many acid/base titrations. If waste cannot be safely neutralized on site, it must be sent to a facility specifically designed for long-term storage or destruction.

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