As we discussed previously, routine or periodic cleaning and disinfection are an important part of an overall workplace Coronavirus safety program, along with hand washing, social distancing and source control measures such as mask use. Additional cleaning and disinfection can be considered in work areas if one or more workers contract Coronavirus.
According to guidelines from the Centers for Disease Control (CDC) at https://www.cdc.gov/coronavirus/2019-ncov/community/reopen-guidance.html, the first step to disinfect a surface is cleaning with soap and water to remove dirt and dust and reduce the amount of virus on the surface followed by application of application of approved disinfectant.
No matter how they are applied, Covid disinfection requires use of approved disinfectants, including 0.1% sodium hypochlorite (bleach) or 70% alcohol (Ethanol or Isopropyl Alcohol)
- Bleach is generally the best option. It is relatively inexpensive and widely available, and (because it is diluted), a little bleach goes a long way
- CDC recommends 0.1% sodium hypochlorite (bleach) solution; this is a 50:1 dilution of household bleach (typically 5%). Remember - Only use 0.1% solution, stronger is not better!
- 5 tablespoons, 1/3 cup or 80 ml bleach per gallon of water or
- 4 teaspoons or 20 ml bleach per quart (or liter) of water or
- 1-2/3 cup or 400 ml bleach per 5 gallons of water.
Make sure to check the expiration date on your bleach container. Also, the bleach solution degrades over time so ACTenviro recommends making new solution every 24 hours as needed. Finally, pay attention to safety. Bleach is corrosive so wear appropriate PPE, including gloves, eye/face protection, mix outsider or in areas that have good ventilation, have spill supplies available and never mix bleach with ammonia or anything other than water!
For surfaces or locations where bleach is not suitable, 70% alcohol (ethanol or isopropyl alcohol) may be used, although these flammable liquids have their own set of safety issues.
- Ethanol & isopropyl alcohol are flammable with unpleasant odors. Use in poorly vented areas for extended periods of time can lead to over-exposure
- Limited contact with skin is generally acceptable (IPA is rubbing alcohol after all), however they can cause irritation over time. Butyl or nitrile gloves will generally provide adequate protection however (as always), users should refer manufacturers compatibility guidelines
The EPA also maintains a list of disinfectants that are anticipated to be effective against Covid/Coronavirus – EPA List N – Approved for “Emerging Viral Pathogens”
- For example List N contains one product with quaternary ammonia as the active ingredient, indicated by an EPA registration number beginning with 1839-166.
- Any other registered products starting with 1839-166 uses quaternary ammonium and is expected to offer equivalent protection, even if not specifically listed
Keep in mind though that Manufacturer’s instructions must be followed and use of any of these materials should be reviewed to determine if additional PPE (including respiratory protection) is required.
Still have questions? See our previous post that looked at cleaning and disinfection requirements or stay tuned for our next post where we will talk about at validation and how to make sure that your cleaning and decontamination process is effective.
