What Concentration of Sodium Hypochlorite is Needed to Sanitize Coronavirus?

The use of sodium hypochlorite, commonly known as bleach, to sanitize against the Coronavirus Disease 2019 (COVID-19), has been a widely adopted method given its effectiveness and versatility. Understanding the proper concentration of sodium hypochlorite is crucial to ensure safe and effective disinfection.

Recommendations from the CDC

The Centers for Disease Control and Prevention (CDC) provides detailed guidelines on the appropriate concentration of sodium hypochlorite to use for sanitizing purposes. For household use, a diluted bleach solution with at least 1000 parts per million (ppm) of sodium hypochlorite or a concentration of 5–6% is recommended.

Preparation and Application

Preparing the solution involves a simple mixture ratio:

For a gallon of room temperature water, mix 5 tablespoons (1/3rd cup) of bleach. For a quart of room temperature water, mix 4 teaspoons of bleach.

These solutions are effective for disinfection up to 24 hours. It is essential to adhere to the manufacturer’s instructions for application and ensure a contact time of at least one minute on the surface being sanitized. Proper ventilation should be maintained during and after the application process.

Dakin's Solution: An Effective Alternative

For those seeking a more specialized solution, Dakin's Solution is a highly effective option. This solution, which contains 0.5% sodium hypochlorite, has been a staple in hospitals and pharmacies due to its potent germ-killing capabilities.

To prepare Dakin's Solution, one can dilute regular store-bought bleach to the recommended concentration by adding approximately 10 parts of water to one part of standard bleach (Clorox). It is important to note that the concentration of water to bleach is not critical, and any container can be used as long as it is dedicated to this solution batch. For convenience and durability, this solution can be stored in the refrigerator and used for up to a few days. However, it should be labeled clearly and used only for surface disinfection.

Risks and Precautions of High Concentrations

It is critical to remember that extremely concentrated solutions of sodium hypochlorite can be highly dangerous if ingested. An accidental ingestion can result in severe health consequences, including potential fatality. It is essential to use and store these solutions with care, particularly in households with children and pets, and to keep all bleach solutions out of reach.

Proper labeling and secure storage should be prioritized to prevent accidental ingestion. Additionally, diluted solutions should only be used for cleaning and disinfection, and never as a substitute for consuming per os treatments.