for Airborne Contamination Control Systems
Delivering the Safest Air to Hospitals – Or Anywhere You Need It
Thursday, April 12, 2007
The Centers for Disease Control in Atlanta (CDC) is continually pushing to reduce potential infection/contamination hazards found in health care facilities. Over the years, many changes in infection control protocol have been made. One of the areas in a healthcare facility that is wrought with potential exposure hazards is an isolation room. To effectively reduce exposure hazards in these areas, the CDC requires the volume of air located in these areas to be replaced multiple times per hour. This provides a dilution effect that reduces the potential exposure hazards to healthcare workers. The CDC has consistently pushed for more air changes per hour in these areas to increase the safety margin. At one time the CDC recommended 6 air changes per hour in an isolation room, today the requirement is 12. These ever-increasing standards come with ever-increasing installation and operational costs. Current regulations require that the air used to achieve multiple air changes per hour be pulled from the outside of the facility, pass through the isolation area and then be exhausted back to the outside of the facility. This procedure directly and substantially increases the amount of energy required to condition the air which also directly impacts your bottom line. Ever-increasing energy costs are here to stay. Airborne Contamination Control, Inc. (ACC) has been working on air quality issues for several decades, and has developed a new, proven concept that allows most of the conditioned air to safely be reused, effectively eliminating the need to exhaust the air to the outside and waste the energy used to condition it. This patented technology is currently deployed in several California hospitals. Those who use it are seeing reduced operational costs and improved air quality.
The HAZVAC III vacuum is a revolutionary concept for capturing and containing hazardous dry particulates. This concept was originally developed to contain hazardous particles in a food processing facility. After years of practical application, research and refinement, this device has been adapted to safely clean face-loaded, specially designed isolation room air filters and greatly extend their useful life. We discovered many years ago that hospitals and burn centers have huge amounts of lint in the air from linens, clothing, bandages, blankets and many other sources. So we prepared the capture filter to face load the lint in order that we could safely vacuum the lint often with our HAZ/VAC IIl. The small amounts of micro-organisms that are within the lint don’t load the filter for a very long time. Because of the van der Waals force the filter will eventually need to be changed. The magnehelic gauge that monitors the filter resistance tells us when and if this needs to be done. This procedure extends the life of our HEPA filters and saves service time. The captured material removed from these filters could contain hazardous pathogens that may be infectious in a hospital environment. The HazVac III is the only vacuum available which provides a method for disposal of hazardous contents from the vacuum safely without the operator wearing a respirator. David Kaiser of ACC has been working with air quality issues for more than 30 years, and has been the driving force behind the development of the HAZVAC III – which can be safely and conveniently used just about anywhere to remove a wide variety of dry, hazardous particulates including beryllium dust and bacteria. A negative force is maintained at the bottom of the capture receptacle during bag replacement. All dust captured is double HEPA- filtered to insure operator safety. Each filter is tested and certified to meet HEPA filter efficiency of 99.97 on 0.3 micron or better.
Prior to 1995, California hospital isolation rooms utilized single-pass airflow ventilation systems to dilute airborne contaminates. All air used in an isolation room had to be exhausted to the exterior of the building after only a single pass. This method was predicated on any contaminants that might be present in the air being diluted and exhausted out of the building. This approach, though costly to build and maintain, does minimize airborne contamination concentrations for healthcare workers. At the same time, however, this process greatly increases the energy required to continuously condition more air to replace the exhausted, contaminated air. In this time of dramatically increasing energy costs, the old concept is proving to be excessively costly.
Aside from operational costs, alternate ventilation systems were not accepted for a variety of reasons. At that time, HEPA (High Efficiency Particulate Air) filtration, for instance, had not attained industry acceptance as complying with rigorous quality standards. It was generally held that HEPA filters could not capture and contain small particulates – such as Tuberculosis bacteria (1-5 microns).
Work by ACC, and supported by the CDC, has shown that HEPA filtration can remove 0.3 micron particulates at greater than 99.97% efficiency, per Federal Standard 209E.
Even though the single pass/dilution airflow concept is commonly used today, it has inherent safety issues. It can be dangerous because of its reliance on a standard ASHRAE rated filter. This air is routinely passed into critical environments without the benefit of HEPA filtration. In hospital settings, such as an isolation room, patients with diminished or suppressed immune systems – or even burn victims – need clean, circulated air. The single-pass/dilution airflow method unnecessarily exposes these patients to a litany of potentially dangerous pathogens that might naturally be in the air surrounding a medical facility.
In 1994, the Centers for Disease Control (CDC) published procedures for controlling the spread of tuberculosis. This publication contains important contributions by Robert T. Hughes, PE; who also worked in association with NIOSH – The National Institute of Occupational Safety and Health. He was also a contributor to the publication Industrial Ventilation - A Manual of Recommended Practice for the American Conference of Governmental industrial Hygienist. Mr. Hughes developed several concepts in air quality management. His three designs illustrated in the CDC publication were great concepts and improved the dilution system. His designs include:
Figure 1: Negative Air Isolation Room.
Year after year, federal regulators have tightened requirements for air changes per hour in isolation rooms in an effort to improve safety for health care providers. The standard, approved method has been to dilute the contamination in every hospital’s environment. Dilution requirements, achieved by air changes per hour, have increased over time. In the past, 6 changes per hour were deemed sufficient. This requirement has since been increased to 10 and now 12 changes per hour. ACC’s system provides 20 or more air changes per hour. Attached to this paper is a letter written by the State of California validating twenty or more air changes per hour.
Maintenance is another issue that is addressed by the ACC solution. Maintenance workers do not like to handle dirty and contaminated filters. Liability can be ascribed to the person or company that asks someone to remove old filters – financial liability can be an issue if the person experiences a contamination hazard on the job. ACC’s solutions can reduce handling contaminated air filters hazards by 95% or more. Why? How? All hospital’s environments produce lots of lint – mostly from bedding, clothes, pillows, bandages, gowns, paper products, etc. An ACC system installed 10 years ago at Cottage Hospital in Santa Barbara, CA (in a TB isolation room) has the face of its filters vacuumed each week. To date, the hospital still has the original filters and the maintenance people love us! The Hospital is willing to provide testament on how pleased they are with our solution.
Our solution provides a double HEPA filtered system. This is a higher standard than any hospital operation room. All the air moves across the room in one direction and is captured immediately behind the patient’s head. Other systems dilute the contamination, whereas we capture and remove the contaminants per HEPA filter standards, drastically reducing contaminate exposure risks for health care workers!
Our system allows the engineering department to continually reuse most of the conditioned air. This reduces the demand on HVAC systems and can save money in design, installation and ongoing operations and maintenance. The single pass air system is getting very expensive to maintain and operate. The centralized HVAC systems also don’t always scale to higher throughputs. When the CDC asks for more air changes per hour, an ACC system can easily be adjusted to comply. Finally, air exhausted to the exterior of the building from an ACC system will be safe for all concerned. This again reduces potential liability.
Mr. Hughes, after developing three new concepts in air quality control, was approached by David Kaiser, seeking collaboration on the new vector filter technology. Hughes was aware of David Kaiser’s efforts to improve air quality systems, and together they agreed on enhancing the airflow concept with newly developed vector filtration media that would greatly advance air purification technology.
David Kaiser extended Mr. Hughes’ filter concepts, developing a totally new methodology for air quality enhancement and mycobacterium removal/capture. Working together, both Hughes and Kaiser agreed that the combination of the airflow concept with the newly developed vector filtration media would prove to be an advance in air purification technology and air quality management.
Figure 2: The Haz/Vac III.
Dave Kaiser created the Single-Direction Air Flow and filtration concept from the combination of these two technologies. He took it to California's 'Organization for Statewide Health Planning and Development’ (OSHPD). They were presented with a schematic of his new concept and for comparison, a schematic of an existing isolation room concept that OSHPD had approved in 1963 for Cottage Hospital in Santa Barbara, CA. Mr. Kaiser was informed that his new design was in violation of the existing State codes for such facilities. ACC organized a call with the California OSHPD and a CDC doctor specializing in respiratory care. The CDC doctor assured OSHPD that a HEPA filter would effectively capture 99.97% of all bacteria 0.3 microns and larger which includes TB bacteria (1 to 5 microns) present in the air.
OSHPD submitted a letter to David Kaiser on December 8, 1995, approving the use of the new air quality control concept for California hospital isolation room. The OSHPD calls the approved concept “Bio-Safe T Zone III Uni-Directional Airflow HEPA Filtration System”. We call it the ‘BIO-SAFE T ZONE III’. Figure shows the room layout – from a high, wall to wall supply on one side of the room, the clean air flows in ONE and ONLY direction. This single-direction flow provides contamination-free air for all healthcare providers that enter the room. The only other alternative is diluted contamination.
ACC has installed the “Bio-Safe T Zone III System” in multiple isolation room facilities in California under the watchful eye of OSHPD since the approval of their proprietary process.
In one specific case ACC was able to reduce the pathogen removal/dilution time from around 5 hours (300 minutes) to less than 60 seconds.
ACC’s advanced air quality management concept satisfies the CDC requirement by increasing the number of air changes per hour to 20 or more in an isolation facility without significantly increasing energy costs. For years the CDC recommended 6 air changes an hour in isolation rooms. That requirement has since been raised to 12 air changes per hour. One ASHRAE publication suggested 37 air changes per hour. Traditionally, all air used to achieve the CDC’s required standard of dilution is conditioned air, introduced to the isolation environment and then exhausted to the exterior of the facility. By increasing the amount of required air changes per hour in an isolation facility, you will also increase the demand on the HVAC system used to condition this air. ACC’s concept allows you to reuse most of the conditioned air and exceed the CDC’s standard for dilution at the same time. By using HEPA filtration to remove pathogens from the air stream, the previously conditioned air can be used safely again and again which greatly reduces the demand on a hospital’s HVAC system.
Your infection control people will love you for reducing their patient’s and employee’s risk of exposure to all types of known and unknown airborne pathogens.
There are many other obvious applications of this single-directional airflow concept including but not limited to surgery facilities, examination rooms, burn units, Haz/Mat command centers, bio-terrorism command centers and any other facility where air quality is absolutely critical. This is the Best Available Technology (BAT) out there today. Don’t let your healthcare providers and patients be exposed to any more hazards than is technologically possible to eliminate. Mr. Kaiser is available to conference with your organization with notice to address all questions relating to this advanced concept. Your employees and your insurance company will be glad you did.
ACC and Water Energy Technologies, Inc. are working together to provide a wide range of air and water quality solutions. For more information about this technology, or help with any air or water quality issue, please contact:
David Kaiser Phone 805.525.6318
Mr. Kaiser has owned and operated ACC since 1978. He has been actively involved in the contamination control business for several decades, and holds several patents in the field. His clients have included hospitals and food manufacturing facilities – places that habitually have air quality issues ranging from viruses and bacteria to mold spore. The cornerstone of his business has been thinking out of the box and providing solutions to existing problems in novel ways. Prior to ACC, Mr. Kaiser was deeply involved in the energy and insurance industries, has been a prominent and active member in the Rotary Club and in the Santa Paula community since attending the University of New Mexico and spending time as a US Navy CB.
Bob Beddingfield Phone 713.464.7117
or email email@example.com.
Mr. Beddingfield is the founder of Water Energy Technologies, Inc. - a solution provider to multiple industries including wastewater management, environmental clean-up and protection, food safety, healthcare, cooling towers, laundry and textile manufacturing. WET provides efficient, practical and durable solutions to chronic problems plaguing these industries. Mr. Beddingfield attended Texas A&M and Sam Houston State Universities and has a Bachelor’s degree in Finance.
 CDC report from October 28,1994: 'Guidelines for Preventing the Transmission of Mycobacterium Tuberculosis”, Vol.43 number RR-13 MMWR; see http://wonder.cdc.gov/wonder/prevguid/m00 35909/m0035909.asp
 Dilution Table
 Re-entrainment Prevention
 See the letter at the end of this paper.