Professional cleaning and testing – What do property managers do if someone tests positive for COVID-19?
In this blog series, EBI Consulting’s Certified Industrial Hygienist, Peter Hosford, has been answering questions about COVID-19 safety protocols for property managers. The first blog post covered measures to prevent transmission of the virus and in-house disinfection processes. But what are the next steps once the virus is present, or suspected to be present?
What do we do if a tenant/visitor show signs of illness or tested positive for COVID-19?
If you suspect someone is or has been ill, or if they have tested positive, there are immediate steps to follow established by the CDC:
- Close off any areas visited by ill persons
- Open outside doors and windows, and use fans to increase circulation
- Consider using 100% outside air from HVAC systems
- Wait 24 hours before beginning cleaning and disinfection
- If it has been more than 7 days since the sick person visited, then no additional cleaning is necessary
- Cleaning staff should clean spaces visited by the sick person, rest rooms, common areas, and high-touch surfaces
- If a sick person is housed in the building, limit the person to a bedroom and separate bathroom, if possible. Limit cleaning and disinfecting in these rooms to minimize exposure to others. If a separate bathroom is not available, the cleaning staff should wait as long as possible before cleaning the rooms
- There is additional CDC guidance for facilities that house people overnight, like institutions of higher education
What should I look for when hiring a cleaning contractor?
Don’t wait until there is an issue to hire a cleaning contractor. You want to take the time to find a reputable company and have them contracted before they are needed. Here are some things to look for in your research:
- Use a known and respected company
- Hazardous waste/Biowaste remediation companies (such as Clean Harbors, Veolia, Triumvirate)
- Cleanup and restoration companies, i.e. disaster recovery (ServePro, Service Master)
- These companies have the equipment, training, and PPE to use industrial strength cleaner safely
- Review and approve the cleaning protocols and cleaning products
- Use a broad-spectrum antimicrobial disinfectant proven to kill bacteria, fungus, and COVID-19 virus
- The company should use cleaning chemicals that meet the EPA’s criteria for use against SARS-CoV-2 (List N)
- Make sure they follow the manufacturer’s directions. Contact time is important. The disinfectant must remain on the surface for the designated period of time specified by the manufacturer. This can be anywhere from 3 to 10 minutes. It may require re-application of the disinfectant, so the surface remains wet for the entire 10 minutes. Allow all surfaces to air dry, then wipe with a clean cloth to remove any residue or film
- Heavily soiled surfaces must be cleaned before disinfecting
Depending on the size of the space being disinfected, there are two cleaning methods that could be employed, each with their pros and cons.
- Small spaces or projects: Clean every surface and article by hand
- Does not leave residue, depending on the disinfectant
- Time consuming
- Large spaces or multiple rooms: Cold fogging with electrostatic sprayers
- Ensure that the fogging of the area takes place for at least 20 minutes
- Foggers need to be set to deliver a 10 – 20 micron particle size for optimal coverage
- Operators must wear personal protective equipment (leave it to the professionals)
- The area will need to be closed to allow a contact time of 10 minutes at minimum
- Turn off your ventilation system
- Hard and high contact surfaces should be wiped down with cleaner after fogging
- Thoroughly rinse food-contact surfaces, including cafeteria tables, with water
Is there a way to verify the cleaning was effective?
There are no standards to help determine how clean is clean, and surface tests for COVID-19 are not readily available, although they could be soon. However, it is possible to use a surrogate (like bacteria or mold) to test the effectiveness of the cleaning. So how does surrogate testing work?
- What are viruses?
- Viruses are pieces of DNA or RNA within a protein capsule
- Viruses do not have cells and do not grow outside of a host. They inject the DNA into the host cell and take it over to make copies of itself. The copies break out of the cell, killing it
- How can bacteria or mold be used as a testing surrogate for the virus?
- The coronavirus has a lipid covering making it easier to kill by disinfection
- Bacteria and mold spores are everywhere, so by taking samples of the surface before and after cleaning, you can test the effectiveness of the disinfection
- If no bacteria or mold is present after cleaning, or the percentage has significantly decreased, you can feel confident the cleaning was effective
- Types of bacteria/mold tests:
- Cultural Bacteria/Mold Swab
- Identify living mold spores and bacteria and swab with nutrient agar
- Turn-around-time is 1 to 2 weeks
- Mold Spore Tape Lift
- Mold spores are found everywhere
- Surfaces can be sampled with a clear adhesive tape then placed onto a microscope slide. The slide is submitted to lab for microscopic identification
- Turn-around-time is 24 hours
- Every living cell contains Adenosine Triphosphate, or ATP. It is the energy source that powers the mechanism of the cell. Viruses do not have cells, and therefore do not have ATP, but bacteria and mold spores do
- How the test is performed:
- The surface is wiped with a swab that is mixed with Luciferin, a compound found in fireflies that generates bioluminescence (makes organisms glow)
- The swab is placed in a photometer to measure the light being emitted, indicating the amount of ATP left on surface
- The swabs should be taken before and after cleaning
- This method is commonly used to test cleanliness in the food industry
- Some caveats:
- The surface must be dry
- Disinfectants that leave a residue (like quaternary ammonia or acetic acid) may negatively interfere with the testing giving a false negative
- Results need interpreting by a professional
As social distancing rules are lifted, it is essential to have a plan ready to go in the event that the coronavirus is present on your property. In the middle of such a crisis is not the time you want to begin your research and planning. These steps are not only critical to prevent a widespread outbreak, but to put your tenants at ease and assure them you have an emergency plan of action. It will also be critical for you and your tenants to know that the cleaning was effective and the property is safe. EBI can help you develop a plan that suits your specific property needs, hire cleaning contractors, conduct testing, and more.
Contact us today to learn about the services EBI can provide to keep your property safe during COVID-19.