Covid-19 Clearance Testing
Assessing Indoor Air Quality
Air quality conditions with respect to HVAC systems, natural and mechanical outdoor/fresh air dilution ventilation, exhaust ventilation and air filtration should be assessed to reduce the potential to transmit COVID-19 infections within the space. Based upon our findings, we can provide recommendations/best practices as may be necessary to enhance ventilation/HVAC and air filtration controls to reduce concentrations of airborne contaminants, including SARS-CoV-2 based on CDC and ASHRAE guidelines. Please call us at 515-724-4574 if you would like to discuss the necessary steps that you and your team can take to minimize your exposure to the COVID-19 virus in the workplace.
Disinfection COVID-19 (SARS-CoV-2)
To further reduce the potential to spread COVID-19 infections, prior to reoccupying the workplace, surfaces within the workplace should be disinfected to reduce levels of viable viruses, bacteria, mold spores, and other biological materials that have settled on surfaces over time. To confirm that surfaces have been adequately disinfected, follow-up COVID-19 efficacy testing should be conducted as discussed below.
EPA Recommended Disinfectants
The U.S. Environmental Protection Agency (EPA) released a list of EPA-registered disinfectant products that have qualified for use against SARS-CoV-2, the novel coronavirus that causes COVID-19.
Products appearing on EPA’s list registered disinfectant products have qualified for use against COVID-19 through the agency’s Emerging Viral Pathogen program.
Coronaviruses are enveloped viruses, meaning they are one of the easiest types of viruses to kill with the appropriate disinfectant product. Consumers using these disinfectants on an enveloped emerging virus should follow the directions for use on the product’s master label, paying close attention to the contact time for the product on the treated surface (i.e., how long the disinfectant should remain on the surface).
The recommended cleaning procedure is to wipe surfaces with a sufficient quantity of disinfectant and to then allow sufficient contact time for the disinfectant to destroy the virus. EPA approved disinfectants and contact times can be found on the EPA’s website by copying and pasting the link in the paragraph below. Vacuuming of any sort is not recommended due to the small size of the virus.
To view the list of EPA-registered disinfectant products, visit https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2
COVID-19 Surface Testing using Polymerase Chain Reaction PCR
Scientists have determined that the SARS-CoV-2 virus consists of a single strand on RNA surrounded by a protein and fatty envelope. Disinfection is achieved by dissolving the fatty/protein envelope using a solution of ethanol, soap, or other disinfectant, which exposes and desiccates the RNA core and renders the RNA virus inactive.
Scientists suspect that the SARS-CoV-2 virus may remain viable on surfaces for several days, depending on the composition of the surface (fabric, cardboard, tile, steel, etc.). The U.S. Centers for Disease Control recommends thorough cleaning and disinfection of frequently touched surfaces to reduce the spread of infection. To demonstrate effectiveness of cleaning protocols, environmental surfaces are sampled using swabs and the swabs are tested using SARS-CoV-2 molecular-based test to determine whether the viral genetic material is present on the surfaces. The method uses the real-time quantitative polymerase chain reaction (RT-qPCR) test, which targets the SARS-CoV-2-nucleocapsid N gene. This method is specified by the CDC and authorized by the U.S. Food and Drug Administration (FDA) for clinical COVID-19 diagnostics.
Clearance samples are taken after cleaning procedures have been completed and sufficient time has elapsed for surfaces to dry. Results are reported in either 'Detected' or 'Non-Detected' for two indicators of the SARS-CoV-2, per swab, as directed by the CDC. Indicator one is 2019-nCoV_N1 and indicator two is 2019-nCoV_N2. Both indicators detect the nucleocapsid protein 'N' gene of the SARS-CoV-2 coronavirus. A result of 'Detected' for either indicator can be interpreted with confidence that the area swabbed did contain SARS-CoV-2 coronavirus particles that could be deemed as potentially infectious.
COVID-19 Cleaning Efficacy Testing
Rather then testing surfaces for the presence of COVID-19 RNA viruses, environmental bacteria testing can be conducted to evaluate the effectiveness of procedures and chemicals used for sanitizing surfaces. Bacteria testing is significantly less expensive, and the presence or absence of bacteria on surfaces can be reliably used as an indicator to determine whether or not surfaces have been adequately disinfected.
Background levels of bacteria can be found on all uncleaned surfaces. The levels depend on the type of surface (bare floors, carpets, walls, ceilings, HVAC systems, etc). If surfaces are adequately disinfected, then levels of viable bacteria on non-porous/hard surfaces (glass, wood, plastic, metal) should recede into the non-detectable range. It can then be inferred that, if levels of viable bacteria or fungi on surfaces are in the non-detectable range, then the likelihood of there being viable viruses on surfaces is small, provided that a virucide was used in the cleaning protocol.
Clearance samples are taken after cleaning procedures have been completed and sufficient time has elapsed for surfaces to dry. The surfaces to be tested are wiped with sterile swabs, and the samples are delivered to a laboratory certified by the New York State Department of Health under The Environmental Laboratory Approval Program (ELAP) of the Wadsworth Center, which is responsible for the certification of laboratories performing environmental analyses on samples originating from New York State. At the laboratory, the samples are plated and analyzed for the presence of bacterial (or fungal) colonies. Results are available within 3 to 4 days. If bacteria is detected, a "Total Aerobic Bacteria Count" will be provided, otherwise, the final report will show as “No Aerobic Bacteria Detected.”
COVID-19 Cleaning Efficacy Testing
Rather then testing surfaces for the presence of COVID-19 RNA viruses, environmental bacteria testing can be conducted to evaluate the effectiveness of procedures and chemicals used for sanitizing surfaces. Bacteria testing is significantly less expensive, and the presence or absence of bacteria on surfaces can be reliably used as an indicator to determine whether or not surfaces have been adequately disinfected.
Background levels of bacteria can be found on all uncleaned surfaces. The levels depend on the type of surface (bare floors, carpets, walls, ceilings, HVAC systems, etc). If surfaces are adequately disinfected, then levels of viable bacteria on non-porous/hard surfaces (glass, wood, plastic, metal) should recede into the non-detectable range. It can then be inferred that, if levels of viable bacteria or fungi on surfaces are in the non-detectable range, then the likelihood of there being viable viruses on surfaces is small, provided that a virucide was used in the cleaning protocol.
Clearance samples are taken after cleaning procedures have been completed and sufficient time has elapsed for surfaces to dry. The surfaces to be tested are wiped with sterile swabs, and the samples are delivered to a laboratory certified by the New York State Department of Health under The Environmental Laboratory Approval Program (ELAP) of the Wadsworth Center, which is responsible for the certification of laboratories performing environmental analyses on samples originating from New York State. At the laboratory, the samples are plated and analyzed for the presence of bacterial (or fungal) colonies. Results are available within 3 to 4 days. If bacteria is detected, a "Total Aerobic Bacteria Count" will be provided, otherwise, the final report will show as “No Aerobic Bacteria Detected.”
Vacuum Cleaners
In a study presented in the National Center for Biotechnology Information entitled Identification of Coronavirus Isolated from a Patient in Korea with COVID-19, where upper and lower respiratory tract secretion samples from patients with COVID-19 were inoculated onto cells to isolate the virus, COVID-19 virus particles were found to be in the 70 to 90 nanometer size range. Given the high airflow velocity in a vacuum cleaners exhaust stream, the concern is that the virus may break through the HEPA filters and be distributed into the room air when vacuuming floors, carpets, and other surfaces. Therefore, vacuuming surfaces to reduce levels of settled dust deposts and other contaminants is not recommended.
COVID-19 Bacteria Testing NYC, COVID-19 Bacteria Testing Brooklyn, COVID-19 Bacteria Testing Westchester
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