Efficacy Report on the Halo Air Purification System Against Aerosolized MS2 Virus

The air within your facility can pose a very real risk to occupant health. However, a new study has found that the Halo air purification system can reduce these risks significantly. Although it does not mean that manual sanitation and health measures, like social distancing and masks, are obsolete, the Halo system itself can go a long way in reducing the spread of COVID-19, as well as other hazardous pathogens.   Scientific studies have a way of sounding completely incoherent to almost anyone who is not familiar with them. We know; we have struggled with scientific; efficacy reports ourselves. Below, the experts here at Action Services Group strive to make these results clearer, breaking down the terms, controls, and findings in a way that everyone can understand.  

Understanding Aerosolized MS2 Virus and Generalized Pollutants 

Before addressing the Halo efficacy report, it is important to understand why these independent tests are considered scientifically acceptable.   The Halo efficacy test utilized aerosolized MS2 bacteriophage, polystyrene latex microspheres, and general particle matter. Using this method of testing with varying types of particles, the Halo air purification system, which utilizes an H14 HEPA filter, was able to fully demonstrate a well-rounded efficacy against different contaminants that can affect an individual’s health.  

  • Aerosolized MS2 BacteriophageAerosolized MS2 bacteriophage is a single-stranded RNA surrogate often used in studies of other traditional illnesses, such as influenza. As such, it is currently being used in laboratories to test the efficacy of various preventative measures against SARS-CoV-2, which is more commonly known as COVID-19 or the coronavirus.  
  • Polystyrene Latex Microspheres: Also known as PLS, polystyrene latex microspheres add another element. Unlike those of in the aerosolized MS2 bacteriophage, PLS particles are available in varying sizes. By using PSL, these tests demonstrate the H14 HEPA filters ability to trap particles with a diameter as small as 0.01 microns.  
  • General Particle Matter (PM) 2.5: Generalized pollutants, including PM 2.5, are also known to impact overall health contributing to over 7 million premature deaths annually. 

By collectively using these three elements, the Halo test is able to establish maximum and comprehensive efficacy. 

As you review the Halo efficacy report we know you will probably have more questions. We have an entire series on Indoor Air Quality, as well as in-depth articles on ventilation effectiveness, and air pollutions link to the global burden of disease.  

The Halo Efficacy Report 

The Halo efficacy report provides valuable insight into the effectiveness of this indoor air quality system. It also demonstrated the overall importance of having a quality air filter installed in a facility.   As with any test, there are controls, baselines, procedures and more. For this Halo P air purification system study, these components are explained below.  


A control ensures that results are precise, without outside influences that may skew data. To test the efficacy of the Halo indoor air purification system, a chamber was constructed from 304 stainless steel. Internal dimensions measured 9.1-feet wide by 9.1-feet deep and 7-feet tall, or 579 cubic feet. This large, sealed chamber allows for a scientific replication of a contaminated room or environment. It also ensured contaminants were not accidentally released into the surrounding area for safety reasons.  

Baseline and Procedures 

To establish a control sample, known as a baseline, the test was performed while the Halo system was off. Since a baseline is performed within the same space, it establishes criteria for which the test data can be compared to.   Once the baseline was established, the Halo air purification system was then turned on. To ensure results were consistent, each test was performed three times under identical parameters. Each of these tests were 90 minutes in duration.  

Data Logging 

Because particle sizes can vary, the data was plotted in a manner that captured this. 


As one of the industries leading indoor air quality systems, the Halo P comes highly recommended by professionals. However, the goal of this study was to determine the effectiveness of the Halo P when exposed to a worst-case scenario of the MS2 bacteriophage. Because it is an acceptable surrogate virus, the MS2 bacteriophage proves the Halo P efficacy in the fight against the spread of the coronavirus.  

The Results 

The study found that the Halo P is extremely efficient in reducing the distribution of MS2 bacteria in the air. In fact, the Halo P air purification system was found to achieve a 1 log reduction. In other words, the Halo P was able to reduce pathogenic air contaminants by 90% within 15 minutes of operation. After 45 minutes of operation, this jumped to a 2.5 log reduction, or 99% decrease in pathogens. At the conclusion of 90 minutes, the Halo P demonstrated a 4.19 log reduction, which equates to a reduction of  99.995%. 

Invest in a Halo Air Purification System with Action Services Group 

The Center for Disease Control and Prevention (CDC) has not clearly determined how much exposure to the SARS-CoV-2 virus will result in a COVID-19 infection. However, using the suitable substitute MS2 bacteriophage, the Halo P has proven that proper ventilation can help reduce potential exposure to contaminants.   To ensure each space is adequately ventilated, however, several factors must be considered. This includes room size, Air Exchange Rates (ACH), ventilation effectiveness (VEFF), and filtration capabilities. It is highly recommended that you work with a professional to determine which system is best for your facility. The experts with Action Services Group can help.   Contact Action Services Group today to learn more about the Halo air purification system and how indoor air quality can help keep occupants safe. Call 610-558-9773 or email [email protected], you can alsoschedule a call by clicking the button below. Website Button - Schedule A Call

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“We are thrilled with our new air purification system and our whole organization can rest easier knowing our buildings indoor air quality is 99.995% filtered of all pollutants. The installation crew was quick, professional, and they cleaned up after themselves. Thank you, Action Services group!”  Director of Human Resources – Transitional Care and Rehabilitation Center