Change your mask before leaving the lab


Updated July 18. 2022

Keep in mind the facemask required for working in a lab is different than the facemask you may wear outside the lab.

If you are working with infectious agents, hazardous chemicals or radiological materials in the lab while wearing a cloth face covering, it could become contaminated during the course of your work and you may not even know it. You could take that biological agent or chemical home with you on your cloth mask - potentially exposing yourself, your family, roommates or the general public. Just like you don’t wear your lab coat and gloves outside the lab, you should not wear a potentially contaminated mask outside the lab.

If your lab work includes handling hazardous materials, or you work is in an area where hazardous materials are being used, follow this guidance to prevent bringing contamination outside the lab:

surgical mask
medical/procedure mask

  • If you wear a mask, whether required or by choice, wear a disposable medical/procedure mask along with other appropriate personal protective equipment (PPE).
  • For work with biohazards, a disposable medical/procedure mask is required at Biosafety Level 2 (BSL-2) and higher. Do not wear a cloth mask during BSL-2 or higher work.
  • Dispose of your mask before leaving the lab, as it could have become contaminated.
  • You can replace your disposable mask with a clean face covering of your choice if you want to wear a mask outside the lab. A well-fitting, high quality facemask is recommended.

If you work in a lab, it is your responsibility to follow safe laboratory practices, including wearing your COVID-19 face coverings in the safest manner possible. For more information, visit the EH&S Face Covering Requirements webpage and review the COVID-19 Face Covering Policy.

If you have questions, contact your principal investigator (PI) or supervisor about providing you and your coworkers disposable masks that may be appropriate for your work environment.

If you have questions about what type of lab work requires wearing disposable face masks, contact EH&S Biological Safety at or 206.221.7770.