This in vitro study characterized the efficacy of the Defend 1050 device at removing aerosolized Bacillus Globigii Endospores. The Defend 1050 device is designed to reduce airborne bacteria, viruses, and fungal spores in order to decrease infections rates from airborne pathogens. For this study the Defend 1050 device was challenged using aerosolized Bacillus Globigii Endospores which has been historically used as a surrogate for Anthrax a biological warfare agent. This study evaluated the efficacy of the device against aerosolized Bacillus Globigii as well as various sizes of polystyrene latex microspheres (PSL) in a stainless steel bioaerosol chamber. The study consisted of a total of four (4) live bioaerosol trials, single (1) bioaerosol control run plus three PSL (3) challenge trials as well as PSL control trials. All trials evaluated the Defend 1050 device on the highest fan velocity setting with the exception of a 24 hour run reported in Appendix B.
Bacillus Globigii was aerosolized into a sealed environmental bioaerosol chamber containing the Defend 1050 device. AGI Impinger samples were taken at 0, 7.5, 15, 22.5, 30 and 45 minutes from the chamber in order to quantify the reduction speed and capabilities of the Defend 1050. AGI impingers were used to sample chamber bioaerosol concentrations, all impinger samples were serially diluted, plated and enumerated in triplicate to yield viable bioaerosol concentration at each sampling point and time. Chamber control trial data was subtracted from the Defend 1050 trial data to yield net LOG reduction in the chamber for the bioaerosol challenges.
When tested against the Bacillus Globigii the device showed a high net log reduction in a relatively short amount of time at the 22.5-minute time point there was an average 4.84 LOG reduction. At the 30-minute time point the Defend 1050 device had an average net log reduction of 5.11. At the 45 minute time point the device showed an average net LOG reduction of 5.56 which equates to a greater than 99.999% reduction.
This study was conducted in compliance with FDA Good Laboratory Practices (GLP) as defined in 21 CFR, Part 58.