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Hazardous materials

Hazardous materials are substances that could harm human health or the environment. Hazardous means dangerous, so these materials must be handled the right way.

Hazard communication, or HAZCOM is teaching people how to work with hazardous materials and waste.

There are many different kinds of hazardous materials, including:

  • Chemicals, like some that are used for cleaning
  • Medicines, like chemotherapy to treat cancer
  • Radioactive material that is used for x-rays or radiation treatments
  • Human or animal tissue, blood, or other substances from the body that may carry harmful germs
  • Gases that are used to make people sleep during surgery

Hazardous materials can harm you if they:

  • Touch your skin
  • Splash into your eyes
  • Get into your airways or lungs when you breathe
  • Cause fires or explosions

Your hospital or workplace has policies about how to deal with these materials. You will receive special training if you work with these materials.

Watch out for Hazardous Materials

Know where hazardous materials are used and stored. Some common areas are where:

  • X-rays and other imaging tests are done
  • Radiation treatments are performed
  • Medicines are handled, prepared, or given to people -- especially cancer treatment medicines
  • Chemicals or supplies are delivered, packed for shipping, or thrown away

Always treat any container that does not have a label like it is hazardous. Treat any spilled substance the same way.

If you do not know if something you use or find is harmful, be sure to ask.

Labels and Signs

Look for signs before you enter a person's room, a lab or x-ray area, a storage closet, or any area you do not know well.

You may see warning labels on boxes, containers, bottles, or tanks. Look for words like:

  • Acid
  • Alkali
  • Carcinogenic
  • Caution
  • Corrosive
  • Danger
  • Explosive
  • Flammable
  • Irritant
  • Radioactive
  • Unstable
  • Warning

A label called the Material Safety Data Sheet (MSDS) will tell you if a material is hazardous. This label tells you:

  • Names of the hazardous chemicals or substances in the container.
  • Facts about the substance, such as the odor or when it will boil or melt.
  • How it could harm you.
  • What your symptoms could be if you are exposed to the material.
  • How to safely handle the material and what personal protective equipment (PPE) to wear when you handle it.
  • What immediate steps to take in case of exposure until more skilled or trained professionals come to help.
  • If the material could cause a fire or explosion, and what to do if this happens.
  • What to do if a spill or leak occurs.
  • What to do if there is danger from the material mixing with other substances.
  • How to safely store the material, including what temperature to keep it at, if moisture is safe, and whether it should be in a room with good airflow.

Work Safely

If you find a spill, treat it like it is hazardous until you know what it is. This means:

  • Put on PPE, such as a respirator or mask and gloves that will protect you from chemicals.
  • Use disinfectant wipes to clean up the spill and put the wipes in double plastic bags.
  • Contact waste management to clean the area and to throw away the supplies you used to clean up the spill.

Always treat any unlabeled container as if it contains hazardous materials. This means:

  • Put the container in a bag and take it to waste management to be thrown away.
  • Do not pour the material down the drain.
  • Do not put the material in the normal trash.
  • Do not let it get into the air.

If you work with hazardous materials:

  • Read the MSDS for all materials you use.
  • Know what type of PPE to wear.
  • Learn about exposure risks, such as whether the material can cause cancer.
  • Know how to use the material and how to store it or throw it away when you are done.

Other tips include:

  • Never enter an area where radiation therapy is taking place.
  • Always use the safest container to move materials from one area to another.
  • Check bottles, containers, or tanks for leaks.

Alternative Names

HazCom; Hazard communication; Material Safety Data Sheet; MSDS


Centers for Disease Control and Prevention website. Personal protective equipment for hazardous materials incidents: a selection guide. Updated April 10, 2017. Accessed October 25, 2023.

Occupational Safety and Health Administration website. Hazard communication. Accessed October 25, 2023.

Review Date 10/13/2023

Updated by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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