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Laboratory Hazardous Waste Management: Classifying and Handling Hazardous Wastes – the Right Way

Laboratory Hazardous Waste Management focuses on handling specific wastes generated from laboratory experiments and research.

By Theresa Gacusan in Guides

What is Laboratory Hazardous Waste Management?

Laboratory Hazardous Waste Management is more complex than ordinary waste management. The activity focuses on handling specific wastes generated from laboratory experiments and research. These wastes are usually complex, toxic, and potentially dangerous to human health and the environment if not managed properly.

Treatment of these wastes involves:

  • Proper characterization of wastes to determine their hazards;
  • Separation of hazardous from non-hazardous wastes;
  • Storage of wastes containing one or more hazardous components;
  • Treatment and disposal of hazardous wastes; and
  • Record-keeping and reporting requirements.

As a general rule of thumb, laboratory hazardous waste management is an activity that requires regular involvement by the principal investigator (PI) to ensure compliance with relevant regulations.

Laboratory Hazardous Waste characterization

Waste characterization is a waste management process that identifies the health and environmental risks of each waste stream and classifies them to determine the appropriate disposal method to minimize risks to workers, communities, and ecosystems. Waste characterization is performed by industrial hygienists, safety professionals, waste generators, or regulators and involves determining whether a waste is ignitable, corrosive, toxic, or reactive.

The outcome of this process is a set of characteristics or properties of the waste called its "hazardous waste code" or "identifier." The most widely used hazard codes are produced by the American Society for Testing and Materials (ASTM), but other systems are also used worldwide. Most countries have developed their hazard codes based on ASTM standards to comply with their regulatory bodies.

Segregating Laboratory Hazardous Waste

Laboratory hazardous waste must be segregated into three categories: solid, liquid, and gaseous.

Solid hazardous waste includes infectious or pathological wastes, culture dishes, discarded chemical reagents, and glassware. It can be placed in plastic bags and stored as-is, as long as the area it's being stored in is properly ventilated.

Liquid hazardous waste includes chemical solutions containing acids or bases, organic solvents, and water from chemical reactions. These wastes must be neutralized before being disposed of; otherwise, they could cause burns or create an explosive environment. They may include thinners, solvents, and stains.

Gaseous hazardous waste contains toxic gases that pose a risk to humans because they can irritate the eyes, nose, and throat or cause headaches and nausea. Gases such as methane, hydrogen sulfide, and carbon monoxide are all examples of gas-based laboratory waste products.

Hazardous Waste Handling and Storage

Handling hazardous laboratory waste involves professionals who can carry out all these processes. The first step is to segregate hazardous waste from other wastes. Next, identify the type of waste and store them separately in labeled containers for future disposal and treatment.

Hazardous Waste Treatment and Disposal

Treatment methods for laboratory hazardous wastes can be divided into two broad categories: environmentally acceptable or technologically enhanced methodologies. Specifically, these methods include physical/chemical treatment such as thermal treatment (incineration), chemical treatment (acid/alkaline hydrolysis), and biological treatment. The choice of a treatment method depends on the characteristics of the hazardous wastes being treated, as well as site-specific considerations. A combination of treatment options may be required to meet site-specific regulatory requirements and protect human health and the environment.

Disposal refers to the final resting place of hazardous waste after all possible treatments have been applied. Waste disposal may be either land disposal or incineration.

Solid chemical wastes are usually disposed of in landfills or incinerated. Wastewater treatment plants are used for liquid chemical wastes, but radioactive chemical wastes require special disposal procedures. In addition to chemical wastes, biological wastes such as animal carcasses and sewage also fall under hazardous laboratory waste.

Radioactive materials are usually disposed of via radiation treatment centers or landfills that have been approved for radioactive material disposal. Infectious agents are treated differently from other laboratory waste because they are usually highly regulated by government bodies.

In general, environmentally acceptable methods are preferred for laboratory hazardous wastes because they are less costly than technologically enhanced methods.

Preventing Hazardous Waste Accumulation

Hazardous waste is a dangerous and expensive problem for laboratories to deal with. Some common concerns associated with hazardous waste management are disposal methods, toxicity, cost-effectiveness of treatment options, and the financial impact on lab budgets. The best way to deal with hazardous waste is to prevent it from accumulating.

There are many ways to prevent hazardous waste accumulation in your lab:

  • Dispose of small amounts immediately after use
  • Do not leave chemicals exposed in flasks or bottles overnight
  • Don't collect larger amounts than you need for immediate use
  • Always keep chemicals in their original containers (bottles, flasks, etc.)
  • When decanting material, transfer it into smaller containers
  • Use reusable glassware instead of disposables (such as pipette tips).
  • Labels should include the name of the product, date prepared, date opened, date expires, usage information, and contact information (name, phone number).

Managing Biohazards

A biohazard is a technical term that means any biological agent that poses a threat to healthy living organisms. It can be a virus, bacteria, or other pathogens that cause illness and disease in a living system. There are levels of biohazard wastes based on their potential risk if they are released into the environment.

Although these levels have been assigned by the Centers for Disease Control (CDC), they are not regulated by any federal agency. These classifications are used by waste management companies to determine the safest disposal method, and they vary from company to company.

There are four biohazard levels as per the CDC.

  • Level 1: Inanimate objects that come in contact with infectious material.
  • Level 2: Contaminated sharps, laboratory cultures from potentially infected patients, and other items that have been exposed to infectious material.
  • Level 3: Clinical specimens that have been collected from potentially infected patients and have been identified as containing infectious material. These items must be placed into a leak-proof container prior to transport.
  • Level 4: Patients who are known to be infected or are suspected of being infected with a pathogen that has the potential to spread through airborne transmission.

Although no federal regulations exist for biohazard classification or disposal, regulated medical waste must be disposed of at a treatment facility that has been registered with the state. These facilities use special incinerators to destroy hazardous medical waste and then dispose of the remaining residue in a landfill. Some states allow for special medical waste landfills that aren't available in all areas.


Management of hazardous laboratory waste will not only help your laboratory dispose of waste in an eco-friendly and cost-effective way, but will also save your staff and employees from accidental exposure and protect the environment.


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