During the COVID-19 pandemic there were several supply shortages that impacted laboratories, including testing reagents and materials, PPE, disinfectants, and other items. If disinfectant products against SARS-CoV-2 on the EPA List N are not available, diluted household bleach solutions can be prepared and used if appropriate for the surface.
Bleach containing 5.25–8.25% sodium hypochlorite should be used to make dilutions with unexpired household bleach that will be effective against coronaviruses when properly diluted. Do not use a bleach product if the percentage is unknown or not within this range. Never mix household bleach with ammonia or any other cleanser as this can cause toxic fumes that may be very hazardous to breathe in. Bleach solutions will be effective for disinfection up to 24 hours.
Prepare a disinfectant solution of bleach by mixing:
- 5 tablespoons (1/3 cup) of 5.25%–8.25% bleach per gallon of room temperature water, or,
- 4 teaspoons of 5.25%–8.25% bleach per quart of room temperature water
Alcohol solutions with at least 70% alcohol may also be used as a SARS-CoV-2 disinfectant. It is important to note that alcohol can evaporate quickly and may need to be reapplied in order to meet contact time recommendations.
Always read and follow the directions on the label to ensure safe and effective use. Wear skin protection and consider eye protection for potential splash hazards. Use no more than the amount recommended on the label, and label diluted cleaning and disinfection solutions accordingly. Use water at room temperature for dilutions (unless stated otherwise on the label). Never eat, drink, breathe or inject these products into your body or apply directly to your skin as they can cause serious harm.
