Objective

To evaluate the efficacy of the Defend 400 at reducing SARS-CoV-2, the virus causing COVID-19.

Methodology

The test was conducted in a 20'x8'x8' (36m³) chamber that complied with BSL-3 standards. The temperature during all test runs was approximately 76 ±2°F (24.4 ±1.1°C), with a relative humidity of 33%. A 6.32 x 106 TCID50/mL of SARS CoV-2 in viral suspension media was nebulized into the room with mixing fans before collection. Air sample collections occurred at 0, 15, and 45 minutes of device operation.

Results

The test results displayed a more rapid reduction in viral concentration than the natural viability loss rates observed. After 15 minutes of operation, the viral concentration decreased from a starting value of 6.32 x 106 TCID50/mL to 3.45 x 106, 3.19 x 106, and 3.00 x 106 TCID50/mL, averaging to approximately 3.21 x 106 TCID50/mL, a 49.20% reduction. With the device operating for 45 minutes, collectable SARS-CoV-2 decreased to an average of 8.76 x 103 TCID50/mL, a 99.86% reduction.

Conclusion

The Defend 400 demonstrated the ability to reduce the concentration of active SARS-CoV-2 from the air at a more rapid rate with an average of 49.20% reduction after 15 minutes and 99.86% after 45 minutes. A net reduction of 99.75% was achieved with the device operating for a total of the 45 minutes time point.