SecureAire Response: The Benefits of Electronic Air Cleaning Equipment in Buildings

Dear Doctors Zaatari, Harmon, and Colleagues:

We read with great respect your “Open letter to address the use of electronic cleaning equipment in buildings” that was recently published about the work by Zang et al1 detailing the chemical by-products from bipolar ionization. As a developer and manufacturer of particle control technologies, SecureAire has been making these same arguments to distributors and clients for the past five years. Specifically, we agree that the uncontrolled bipolar ionization with electronic corona pins and points, various plasma, and photocatalytic oxidative processes used by many electronic cleaning devices results in chemical reactions that generate reactive oxygen species, volatile organic compounds, ozone, and other toxic compounds. We also recognize that the application of a small experimental chamber or even single room results cannot be directly applied to real world settings.

SecureAire distinguishes its technology from others in four unique ways: we have a different mechanism of action, we have conducted a series of studies documenting the objective impact within the ventilated space on particle counts and, not within an enclosed experimental chamber or within the ventilation ducts 2, we have been able to kill biologic material within a real-world hospital compounding pharmacy and other real-life locations by measuring bacterial contamination 3, and finally we have deployed our purification technology in a live, facility-wide environment which has resulted in a 45% reduction in health care-acquired infections 4.

Unlike ionizers which sends out a single charge in an uncontrolled manner to airborne particles, the mechanism of Particle Control technology imparts both positive and negative charges in a controlled manner on individual particles and pathogens. The technology platform developed by SecureAire, works through a process called local electromagnetic field manipulation which involves particle conditioning using controlled ionization, enhanced and controlled polarization, and controlled particle transport. Employing Gauss’ Law (Maxwell’s first Equation) we control to transport of particles and decrease the mean free path of collisions, especially influencing fine, ultrafine, and nano particles. In utilizing both positive and negative charges and the electric fields associated with these charges, the free path between collisions are minimized and as the force of attraction is maximized, particles are more attracted to each other rather than being attracted to surfaces, objects, or occupants of the treated space. Independent third-party experiments of ACTIVE particle control technology documented the maximum Ozone reading over a 24-hour period was 1.1ppb, which is exponentially lower than the CARB/FDA/UL 867 standards and a fraction of the ASHRAE Standard 62.1 2019 5.

These forces condition the microparticles and pathogens within a space, so they continuously initiate millions of particle-particle (ionization) and particle-molecular (polarization) collisions. These collisions lead to immediate and permanent ionically driven aggregations of fine and ultrafine particles and pathogens into larger particles. With the larger aggregates attaining a critical mass, their transport becomes controlled by airflow and they can be carried by air currents to the particle collector, and/or driven out of the occupied space via an exhaust pathway.

ACTIVE Particle Control™ technology, has been shown to reduce fine and ultrafine airborne particles and pathogens in live operating rooms, reduce bacterial contamination in active hospital compounding pharmacies, and rapidly inactivate or kill the highly resistant anthrax surrogate (Bacillus subtilis) 6.

The behavior of all particles (pollutants, aerosolized or airborne viruses and bacteria, pollen, etc.) are guided principally by the laws of electromagnetics and not as much by mechanical influences, such as airflow or gravity, and to a smaller degree, chemical and biological influences. It is the mass and spatial characteristics of these ultrafine particles (including virus and bacteria) that keep them suspended for long periods of time allowing for wide field dispersion or diffusion. Treatment with our technology leads to the controlled aggregation of particles and pathogens. Once aggregated, particles and pathogens build mass which increases their subjectivity to mechanical laws.

Our own work and that of others objectively confirms the above and we concur with the statement recently but distinguish our technology from bipolar based devices for the above technical reasons. We look forward to the publication of our work under review of >100,000 patient days over 30 months in a live real-world 124 bed hospital that objectively measured particle counts, viral and bacterial bioburden, and health care-acquired infections 7.

We welcome the objective study by others of our novel engineering solution in combating the transmission of viral and bacterial diseases, indoor air pollution and COVID-19.

Sincerely, Mark Ereth, MD, Chief Medical Officer, SecureAire, Inc, Emeritus Professor of Anesthesiology, Mayo Clinic College of Medicine and Science


1Zeng Y, Manwatkar P, Laguerre A, et al. Evaluating a commercially available in-duct bipolar ionization device for pollutant removal and potential byproduct formation. Build Environ 2021.

2Ereth, et al, Particle control reduces fine and ultrafine particles greater than HEPA filtration in live operating rooms and kills biologic warfare surrogate, Am J Inf Control, 2020.


4Ereth, et al, Health care-associated infection impact with bioaerosol treatment and COVID-19 mitigation measures, Under review, J Hosp Infection, 2021.

5Ozone Emissions Test Report, Intertek, 12-18-20, Report 104438992CRT-001.

6Ereth, et al, Particle control.

7Ereth, et al, Health care-associated infection impact.

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