During the COVID-19 pandemic, several supply shortages 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 unavailable, 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 adequately 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. 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
Alternatives containing at least 70% alcohol may also be used as a SARS-CoV-2 disinfectant. However, alcohol can evaporate quickly and may need to be reapplied 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 the recommended amount 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 them directly to your skin, as they can cause serious harm.
