Testing the Effectiveness of Safer Solutions
To protect workers and building occupants from the health effects of toxics in disinfectants, TURI has been providing guidance on how to disinfect spaces safely. One way we’ve done this is to identify products on the EPA’s N List that contain safer active ingredients.
We want to better understand how well those products work to destroy the SARS-CoV-2 virus that causes COVID-19. We also want to know how well devices, as well as other formulations not on EPA’s List N, work to destroy the virus.
To find answers, TURI Cleaning Lab researchers are testing the efficacy of various safer disinfectants and devices to inactivate the virus on non-porous and porous surfaces using recognized analytical methodologies. We are doing this using the MS2 bacteriophage – a recognized non-enveloped surrogate for the SARS-CoV-2 virus that is safer to work with.
Testing the Performance of Safer Options
The TURI Lab is comparing the effectiveness of bleach and quaternary ammonium compounds, which work but cause health effects, with these safer options for both commercial and community use. The safer options currently being tested include:
- Aqueous Ozone
- Sodium diisocyanurate (NaDCC) tablets
- Electrochemical Activation (ECA) devices
- Steam cleaning
- UV-C devices
- Other devices
Can All Purpose Cleaners Disinfect?
Recent research efforts at the TURI Lab investigated how well several all-purpose products worked on reducing viral load on a surface. Researchers used the MS2 Bacteriophage (virus surrogate) to test the effectiveness of products. This organism is a small non-enveloped virus, roughly the same size as the SARS-CoV-2 virus. Unlike the SARS-CoV-2, the MS2 is safer to work with in a lab setting.
Based on the difference in the structure of the organisms, if a product kills MS2, then it will kill the SARS-CoV-2 virus that causes COVID-19. However, if the product doesn’t kill MS2, this doesn't necessarily mean that the product doesn’t work. Additional testing would then be required on an enveloped virus.
The TURI Lab has conducted preliminary testing on five all-purpose cleaners to demonstrate effectiveness. These were all products marketed as all-purpose cleaners that do not contain harmful chemicals. Some of the products contained vinegar or hydrogen peroxide, which are chemicals with known disinfecting capabilities in addition to their cleaning abilities. The products were effective at reducing virus surrogates by 70-99%.
Evaluating Exposure to Chlorine Generated from Devices
To find out if devices that generate chlorine-based chemicals, such as hypochlorous acid, could be safer to use than chlorine bleach, TURI is measuring chlorine exposure from six devices and one concentrated tablet.
The testing includes two steps:
1) Determine the total chlorine concentration in parts per million (ppm) after mixing the solution. After mixing water with either salt, vinegar or a pre-packaged tablet per the manufacturer’s directions, TURI staff measured the concentration of the solution. The results showed a range of concentrations from 100 ppm to 1,200 ppm.
2) Assessing potential worker exposure to aerosolized chlorine when using the solution. While spraying on surfaces, TURI researchers are using a chlorine detection device to measure potential airborne exposures.
TURI is continuing to conduct this research and will release the results once complete.