Prion Disinfection Options

Prions are characterized  by extreme resistance to conventional inactivation procedures including irradiation, boiling, dry heat, and many chemicals (formalin, betapropiolactone, alcohols). Fixation with alcohol, formalin, or glutaraldehyde strongly stabilizes the infectivity of prions and makes them more difficult to inactivate. Formalin-fixed and paraffin-embedded tissues, especially of the brain, remain infectious. As a consequence, contaminated materials should not be  exposed to fixation reagents, and should be kept wet between the time of use and disinfection by immersion in chemical disinfectants. Fixed material that contain or may contain prions must be disposed of as "prion waste".

Note: Be sure to decontaminate all equipment prior to maintenance or service work. 

Effective Disinfectants

  • 40% household bleach, per USDA requirements (2% free chlorine by making a final concentration of 2.5% sodium hypochlorite solution) with a one-hour contact time
  • Freshly made 2N NaOH with a one-hour contact time

In addition to the above disinfectants, prions can be inactivated by:

  • Steam autoclaving at 134°C for one hour, or
  • Incineration

Disinfection of Surfaces and Laboratory Equipment

  • Flood with 2.0N NaOH or full-strength household bleach and let stand for one hour. Mop up and rinse with water.
  • Clean with 1.0N NaOH allowing a 5-minute contact time, followed by a wipe down with 1.0N HCl. Rinse with water. 
  • If possible, autoclave the equipment at 134°C for one hour.

Spill Cleanup

  • Notify other lab workers that a spill has occurred
  • Keep contaminated surfaces moist until decontamination is complete, as the infectious agents become even more resistant to chemical inactivation when dry.
  • Cover spill with paper towels or other absorbent materials. 
  • Saturate with 2N NaOH or 40% bleach and let sit for at least 60 minutes. If possible, leave the lab to avoid prolonged breathing of fumes. 
  • Direct other workers not to enter the lab.
  • Dispose of absorbent material and any other cleanup material in yellow waste bag.
  • Report all spills to lab supervisor.