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Air purification for IVF clinics

Posted by Jean Shaw-Leonard on Jan 21, 2013 9:59:00 AM

This article was published in Cleanroom Technology in November 2009. 

The ZAND-AIR PCOC™3 has since been updated with the addition of the PPF Activated Carbon Filter. This optional filter has found very good acceptance as well. Over 2,500 zIVF-AIRe™ 100C units have been sold since 2004. 

Air purification for IVF clinics

Sensitive procedures such as egg retrieval (above) require air free of contaminants


Technology developed for destroying toxic organic compounds and used by the US Department of Defence is now finding application in IVF treatment laboratories. Susan Birks reports.


As technology has advanced, the necessity to filter air has become more important. Today, many working environments require air to be free of pollutants. Dust, mould spores, pollen, dust mites, viruses and bacteria are the normal contaminants that industries are keen to keep out of products. However, some sectors find the removal of other pollutants, such as cleaning chemical components, volatile organic compounds (VOCs), automotive emissions, aldehydes, carcinogenic materials, carbon monoxide, as well as chemical air contaminants (CACs) such as sulphur and nitrogen oxides, equally important.

Nowhere is the removal of these pollutants more critical than in IVF facilities, where the quality of air in laboratories and clinical procedure rooms can have enormous effects on embryo quality, embryo survival, and hence clinical outcomes of IVF treatment.

Pollutants that can affect IVF outcomes include aerosolised pesticides, small inorganic molecules, such as nitrous oxide and sulphur dioxide, as well as heavy metals, such as lead. Many of these common pollutants can settle on work surfaces or the surfaces of tissue culture plastic ware and also dissolve in aqueous solutions of embryo culture medium.

Fresh air intakes in urban areas can contain high levels of VOCs, nitrous oxide and sulphur dioxide, as well as heavy metals, road tarmac and tarmac sealant. In addition, construction materials, MDF, PVC flooring, paints, fillers, adhesives, cleaning products and aerosol propellants are a major source of VOCs. Plastics can outgas plasticisers and mould releasing agents. Added to these are the chemical irritants lurking in the cleansers and waxes used to keep work surfaces clean, lab solvents, even perfumes, aftershaves and cosmetics and cigarette smoke.

As a result of growing evidence that air contaminants can affect IVF outcomes, cleanroom specifications for particulate and micro-organism contamination for IVF labs were introduced in the EU Tissue Directive 2006/86/EC. But removal of all of these contaminants would require very high specification air handling systems.

Based on a 2007 study, the US-based Zander Group of companies believes its air purification systems are suitable for use in an IVF facility. The study, published in the reproductive medicine journal Alpha Science,1 was designed and carried out to assess the levels of construction and product related VOC off-gassing in a newly constructed IVF laboratory with three Zand-Air 200 units installed in series in the HVAC system and to assess the performance of floor-standing zIVF-AIRe 100C air purification units in reducing ambient VOC levels in an IVF lab.

The results of the study confirmed the efficiency of the air handling units, including the photocatalytic VOC removal units in the HVAC system supplying the embryology laboratory, says Zander Group. Moreover, the results also illustrated the value of having additional in-laboratory photocatalytic ‘air polishing’ units to help eliminate locally generated VOCs.

According to Zander, the key to effective air purification is its patented photocatalytic oxidation process, where titanium dioxide in the photocatalytic chamber is exposed to specific wavelengths in the ultraviolet C radiation region (253.7nm). This makes the titanium dioxide highly reactive and thus acts as a photocatalyst ‘attacking’ the chemical bonds of organic pollutants such as solvents, alcohols, carbon monoxide and fuel oils, and converting them into benign compounds such as water and carbon dioxide.

Destroying hazardous TOCs

Based on a concept first developed in the US by Sandia Laboratory and the National Renewal Energy Laboratory and used by the US Department of Defence for destroying toxic organic compounds that are hazardous to human health and the environment, this powerful air cleaning technology is now being put to wider use.

The processes carried out by the air purification systems are outlined in the following four stages: Step one: The front position activated carbon filter (ACF) with specially formulated gas adsorption media (including zeolite and potassium permanganate) adsorbs automobile exhaust fumes, organic hydrocarbons, formaldehyde from particle boards used in construction, paints, solvents, chlorine, cleaning chemicals, VOCs, CACs and other harmful and carcinogenic agents.

Step two: A rear position HEPA filter of hospital grade and certified to have an efficiency of not less than 99.97% for 0.3µm particles, removes particles – pollen, mould, fungal spores, dust mites, viruses, and bacteria – down to 0.3µm in size.

Step three: The photocatalytic oxidation converts toxic compounds, including carbon monoxide and nitrous oxide, into benign constituents such as carbon dioxide and water. The catalyst does not wear out or lose effectiveness as a result of its action.

Step four: Ultraviolet light kills the bacteria and viruses that are too small to be filtered out by the HEPA filter. The UV lamp used in the zIVF-AIRe 100C has an output that is 99% in the 254nm wavelength range. This wavelength destroys bacteria and viruses and does not produce ozone as a result.

Zander says the air quality produced by systems using UV tech-nology combined with photocatalytic oxidation far exceeds that of other systems that depend solely on filtration or ionisation. In addition, the systems use microprocessor and computerised electronic motion sensors to monitor air quality and automatically increase the performance of the air purification system while the solid state sensor detects toxic fumes, to compensate for periods of increased human activity and unusually high chemical activity. Warning lights are also incorporated to alert staff to the presence of toxic chemicals and fumes well before they reach dangerous levels or become detectable to the human senses.

Air purification for different applications

Zander Group offers five air purification systems for different applications and spaces: The zIVF-AIRe 100C Clean Air System, suitable for IVF labs; this is effective on a variety of odours and gases, including diesel fumes, food, hospital odours, paint solvent, VOCs and CACs, acid gases such as hydrogen sulphide, sulphur dioxide and hydrogen chloride. It is also formulated to absorb very light gases such as ammonia, formaldehyde and other aldehydes. The ZAND-AIR 100P Air Purification for biochemical, histology and pathology laboratories; this system can play a major part in protecting laboratory staff from harmful compounds such as zylene, toluene, benzene and other carcinogenic agents. The ZAND-AIR 200 for existing HVAC systems and new constructions; this system is designed to be incorporated into new or existing constructions and renovations to protect people in lab environments against indoor air pollutants. It can convert VOCs and CACs, viruses and bacteria into H2O and CO2, and harmless small particles, all within the capacity of existing HEPA filters, activated carbon filters, and blowers of the existing HVAC equipment. The ZAND-AIR PCOC3 combines in one frame three chambers of the model ZAND-AIR 200, saving space in HVAC units and assisting in airtight installations in HVAC and ductwork with VAV units. The ZAND-AIR 20C CLEAN AIR filtration and purification system is for the office.

Contact Zander Scientific 755 8th Court, suite #4 POB 650790 Vero Beach Florida, Fl 32965-0790, USA T +1 772 569 5955 www.zandair.com


Zander PCOC3

The ZAND-AIR PCOC3 combines three chambers of the model ZAND-AIR 200, saving space in HVAC units and assisting in airtight installations (the handles are not supplied)

Zander schematic

Schematic showing the photocatalytic air polishing process

Topics: air filtration purification, air filtration, Volatile Organic Compound, VOCs, Air Quality, IVF

“In Door Air Quality in Hospitals”

Posted by Fred Zander on Nov 5, 2012 1:25:00 PM


“In Door Air Quality in Hospitals, Photo Catalytic Oxidation Technology for air purification”

Hospitals are one of the fundaments of the society in a country and patient comes to the Hospitals to get treatment and regain health. When designing a HVAC system for a Hospital there are several key parameters to take into account:

  • Reduce Hospital Acquired Infections
  • Ensure HVAC Energy Savings
  • Lower labor, maintenance and disposal cost
  • Achieve sustainability

This paper focuses on the reduction of Hospital Acquired Infections, and discusses various aspects of dilution, filtration and air purification in Hospitals. The main part describes the use of Photo Catalytic Oxidation Technology for air purification in hospital facilities. At the end of the article a brief presentation of the product ZAND-AIR PCOC™3 is included.

The nature of the people and the process taking place at hospital needs to be understood and taken into consideration when designing HVAC system for optimal In Door Air Quality (IAQ). Patients and health care practitioners can carry biological pathogens (bacteria, virus and fungi) which can be transmitted to peers. Some of the patients are immunosuppressed . Through surgical operations and other activities in Operating Theaters (OT) patient are exposed due to open wounds and surgical scars. There has been an ongoing debate between professionals if Infectious diseases are airborne or not over the past decade. ASHRE has reviewed the available literature and published a position document in 2009, stating that many infectious diseases can be airborne, and hence HVAC construction in Hospitals needs to be designed to prevent cross infections. (ASHRAE 2009)

 “Many infectious diseases are transmitted through inhalation of airborne infectious particles termed droplet nuclei.”

“Airborne infectious particles can be disseminated through buildings including ventilation systems.”

More than 60 bacteria, virus and fungi are documented as infectious airborne pathogens. Diseases transmitted via bio aerosols include; Tuberculosis, Legionaries, Influenza, Colds, Mumps, Measles, Rubella, Small pox, Pneumonia and Meningitis (Saito 1992). One of the most common and harmful bacteria’s which can be found and transmitted in Hospitals are Methicillin Resistant Staphylococcus Aureus (MRSA). The prevalence of MRSA in Hospital in Indian has been reported to be 27% in Bombay, 43% in Delhi and 47% in Bangalore. (Metha 1996) The prevalence of MRSA in India was reported in one study to increase from 12% in 1992 to 80.83% in 1999. (Werma 2000). Once introduced into a hospital MRSA frequently becomes endemic, difficult to control, expensive to treat and often very difficult to eradicate. MRSA causes major morbidity and mortality. MRSA was reported to cause 19,000 deaths 2008 in the U.S and a patient who contracts it while hospitalized stays an average 10 days longer and costs an additional $30,000.     (JAMA 2010).

While 1 in 10 people have the MRSA bacteria on their skin, and don't necessarily become sick from it, a new superbug, NDM-1 is now appearing in hospitals in the U.K and the U.S. It has quickly become one of the most feared infections. NDM - 1, discovered in New Delhi (hence the name New Delhi metallobeta-lactamase, or NDM-1) makes bacteria resistant to antibiotics. (Walsh 2011)

 Dilution and air Distribution

There are two basic physical principles behind the roles of ventilation in infection control. The first is through dilution of airborne pathogens, and the second is the control of movement of airborne pathogens from one space to another in the hospital operating room. Opinions vary regarding the importance of airborne contamination with respect to post-operative infection. It is generally agreed that the majority of infections are caused by contact contamination from the patient themselves or the surgical team. Studies have also indicated a relationship between the incidence of infection and the level of air contamination. While the validity of these results can be discussed due to changes in surgical gowns, surgical techniques, antibiotics, etc., the consensus is simply that the air should be kept as clean as possible. The largest sources of contamination in a sterilized operating room, with a clean air supply and isolation from adjacent areas, are the surgical team and patient. The function of the operating room’s air distribution system therefore must be to carry away any contaminants expelled into the air by either the surgical team or the patient on the operating table. The system must also isolate and remove this contaminated air so it cannot mix with the clean supply air.

The simplest way to reduce the airborne contaminants present in the operating room is to increase the air ventilation rate. Minimum air changes per hour are defined by ASHRAE, AIA and ASHE for most of the areas in a Hospital. There seems to be a consensus for a minimum of 12-15 ACH in critical areas of hospital like Operation Theaters, ICU and Protective Environment rooms. For less critical areas in a hospital the recommendation is 4-6 ACH. In general 2-3 ACH of fresh air is demanded, which ensures good air quality and gives the possibility of energy savings through recirculation of a large amount of the air.

Laminar flow ventilation system was developed to provide a method of controlling the transport of air contamination by introducing the supply air into the operating room at low uniform velocities promoting a stable downward flow of air. Although laminar flow diffusers discharge air at low face velocity, some entrainment of room air still occurs. This entrainment in combination with the temperature differential of the supply air causes the air pattern to angle towards the center of the discharge air envelope. As a result a clean zone is created around the patient.


Another solution to disinfecting the air is to capture offending particles in a filter mesh of some kind. HEPA and ULPA filters are specifically designed for the collection of submicron PM (Particulate Matter) at high collection efficiencies. Key metrics affecting function are fiber density and diameter, and filter thickness. The air space between HEPA filter fibers is much greater than 0.3 μm. The common assumption that a HEPA filter acts like a sieve where particles smaller than the largest opening can pass through is incorrect. Just as for membrane filters, particles so large that they are as wide as the largest opening or distance between fibers cannot pass in between them at all. But HEPA filters are designed to target much smaller pollutants and particles are mainly trapped (they stick to a fiber) by either interception, Inertial Impaction, Diffusion or Sieving.

The relevant size measurement used in aerosol science is the aerodynamic diameter. This diameter is usually different from the actual particle size of microorganisms, and accounts for the non-spherical nature of the cells. This parameter is more useful for predicting aerodynamic behavior of a particle in air. Viruses are the smallest, ranging in size from 0.01 µm to 0.4 µm, while fungal spores are at the upper end of the range and can be larger than 20 µm. Bacteria range in size from 0.5 to 10 µm.

Filtration is an effective way of controlling the aerobiology of indoor air.  However reports show that microorganisms can grow on untreated air filters and even grow through the filters and release spores downstream. (Kemp 1995) Other studies have reported or shown that microbes can survive or grow on filters. Coincident with the problem of growth of fungi on filters is the possible generation of VOCs. Laboratory experiments proved that species of Aspergillus, Cladosporium, Acremonium, and possibly other microbes may produce acetone, ethanol, formaldehyde, acetaldehyde and other compounds on fiberglass and cellulose filter media (Schleibinger 1999). Furthermore HEPA filter has a substantial pressure drop which increases over time.

ASHRAE guidelines propose using two filter beds containing MERV 7 and HEPA filter in critical areas of a Hospital and two filter beds containing MERV 7 and MERV 13-14 in less critical areas in a Hospital. (ASHRAE 2011)

Purification - Photo Catalytic Oxidation

Several attributes of Photo Catalytic Oxidation make it a strong candidate for indoor air quality (IAQ) applications. Pollutants, particularly VOCs, are preferentially adsorbed on the surface and oxidized to (primarily) carbon dioxide (CO2). Thus, rather than simply changing the phase and concentrating the contaminant, the absolute toxicity of the treated air stream is reduced, allowing the photo catalytic reactor to operate as a self-cleaning filter relative to organic material on the catalyst surface. (Jacoby 1996) Bacteria and viruses are destroyed by the clastogenic effect of UVC. The process is called heterogeneous photo catalysis or photo catalytic oxidation. In chemistry, photo catalysis is the acceleration of a photoreaction in the presence of a catalyst. Titanium dioxide (TiO2) is a common catalyst for air purification. Titanium dioxide is a semiconductor photocatalyst with a band gap energy of 3.2 eV. When this material is irradiated with photons of less than 385 nm, the band gap energy is exceeded and an electron is promoted from the valence band to the conduction band. The resultant electron-hole pair has a lifetime in the space-charge region that enables its participation in chemical reactions. The most widely postulated reactions are shown here.

OH- + h+ _________> .OH

O2 + e- _________> O2-

Hydroxyl radicals and super-oxide ions are highly reactive species that will oxidize volatile organic compounds (VOCs) adsorbed on the catalyst surface. They will also kill and decompose adsorbed bio aerosols. (Goswami 1995)

The photo catalytic deactivation of bacterial cells has been widely reported in the literature. There is substantial evidence that the mechanism of cell killing with PCO is the damage of the cell membrane. (Blake 1999)  The cell membrane contains unsaturated phospholipid and, therefore, is the potential target leading to lipid peroxidation. The detrimental impact of lipid peroxidation to all forms of life has been well documented in the literature. There is still conflicting evidence in the literature as to which reactive oxygen species are directly involved in the photo killing process.



The ZAND-AIR PCOC TM3 has been developed for air purification in laboratories and medical facilities. The ZAND-AIR PCOC TM3 contains a MERV 13 filter, three Photo Catalytic Oxidation Chambers and an additional slot for a Potassium Permanganate Filter (PPF). The frame body of the ZAND-AIR PCOC TM 3 between flanges is: W 629 mm           L 784 mm             H 520mm

Each PCO Chamber contain of 2 UVC lights of 20 W with reflectors, illuminating a substrate of TiO2 nanoparticles. The ZAND-AIR PCOCTM3 use a patented process to affix TiOnanoparticles to a solid substrate, for this TiO2 to interact with UVC radiation at 253, 7 nm. To increase the efficacy of the PCO process three PCO chambers are placed sequentially in a single frame, thus increasing the dwell time for the airstream through the PCO-Chambers.



The pressure drop of three units of PCO chambers without MERV 13 and Potassium Permanganate Filter is:

2000 CFM

14,9 PA

1600 CFM

7,5 PA

1200 CFM

2,5 PA




The nominal air capacity for the unit is 2000 CFM. While the photo catalytic process is very fast the number of the photo catalytic actions occurring in the PCO Chamber are multiple and sequential. Using a high proportion of return air (>85%) as the part of the airstream is thus helping the cleaning process, as the return air already passed before through the photo catalytic oxidation process. From a service perspective the UV-lights needs to be changed every 12 month, and the MERV 13 and PPF filter every 6 months or sooner.

There have been reports in the literature of air purification products generating harmful byproducts such as ozone.  A study has been performed to evaluate if any harmful byproduct is produced by the ZAND-AIR PCOC™3.                 

“The evaluated PCOC3-unit, operating with a UV-wavelength of 253.7 nm and a TiO2 catalyst showed no signs of ozone generation. Instead, the results indicate that ozone was captured by the device at a removal rate of 67 ach, corresponding to a single pass efficacy about 15%” (Kadrobegovic 2010)

The ZAND-AIR PCOCTM3 combines the efficacy of the UV-light and the Photo Catalytic Oxidation Technology. The below graph shows an example of a PCO system disinfecting air in a recirculation system.  In this graph the disinfection due to UV alone is graphed for comparison.  Based on comparison of the effective rate constants, the effect due to UV appears to account for 63% of the disinfection, while PCO accounts for an additional 37% reduction. (Goswami 1997)


Studies have been performed at the Polytechnic University in Hong Kong confirming the removal efficacy on biological pathogens of the Zandair product. A single PCO Chamber air purification system was operating in recirculation mode in a test room and the cfu/m3 levels (Colonizing Forming Units) was measured over time. After 120 minutes of operation a reduction from 111 to 7 cfu/ m3 was reported. (Chan 2004).

The ZAND-AIR PCOCTM3 has been successfully installed in In Vitro Fertilization (IVF) Laboratories since 2008. Culturing human embryos and cells is one of the most sensitive environments which has very high demands of clean air, free from VOCs and biological pathogens. Successful Installations of the ZAND-AIR PCOC™3 has been done in USA, Canada, UK, Spain, Ireland and India.



Photo catalytic reactors may be integrated into new and existing heating, ventilation, and air conditioning (HVAC) systems due to their modular design, room temperature operation, and negligible pressure drop. PCO reactors also feature low power consumption, potentially long service life, and low maintenance requirements. These attributes contribute to the potential of PCO technology to be an effective process for removing and destroying low level pollutants in indoor air, including bacteria, viruses and fungi.


 ASHRAE 2009, position paper, Airborne Infectious diseases.

 ASHRAE 2010, Ventilation of Health Care Facilities

 ASHRAE 2011, Addendum to standard 170-2008 Ventilation of Health Care facilities

 Blake 1999, Application of the photocatalytic chemistry of titanium dioxide to disinfection and the killing of cancer cells, Separation and Purification Methods Volume 28(1).

 Chan 2004, Test Report, Hong Kong Polytechnic University

 Dikema 2008, Preventing MRSA Infections: Finding is Not Enough JAMA, 2008:299(10): 1190-1192

 Goswami, 1995, Photocatalytic disinfection of indoor air, Solar Engineering ASME 1995 1: 421-427

 Jacoby 1996, Heterogeneous photocatalysis for control of volatile organic compounds in indoor air. Journal of Air & Waste Management 46: 891-898

 Kadrogebovic  2010, Air Cleaning by Photo Catalytic Oxidation:An Experimental Performance Test,  ASHRAE Transactions, Volume 117, Part 1.

 Kemp, 1995 Growth of microorganisms on HVAC filters under controlled temperature and humidity conditions. ASHRAE Trans 101, 305-316.

 Matusunga 1985, Sterilization with particulate photosemiconductor. Journal of Antibacterial Antifungal Agents 13: 211-220.

 Mehta 1996, A pilot programme of MRSA surveillance in India. (MRSA Surveillance Study Group). J Postgrad Med 1996;42:1-3

 Saito 1992, Mode of photocatalytic bactericidal action of powdered semiconductor TiO2 on Streptococci mutans. Journal of Photochemical Photobiology 14: 369-379.

 Schleibinger 1999, Accumulation of endotoxins on air filters in heating, ventilating and air conditioning (HVAC) systems, Indoor air'99, Edinburgh, Vol 2, 243244.

 Verma 2000, Growing problem of methicillin resistant staphylococci - Indian scenario. Indian J Med Sci 2000; 54:535-40

 Walsh 2011, Dissemination of NDM-1 positive bacteria in the New Delhi environment and its implications for human health: an environmental point prevalence study, The Lancet Infectious Diseases, Volume 11, issue 5 Pages 355 - 362, May 2011.


Topics: air filtration purification, MRSA, photocatalytic oxidation, infection control, airborne infections, infection prevention, Hospital Acquired Infections

AIRBORNE PATHOGENS: Superbugs Ride Air Currents Around Hospital Units

Posted by Jean Shaw-Leonard on Oct 12, 2012 5:30:00 PM

Eliminating from the hospitals and medical laboratories any disease causing airborne pathogens and volatile organic compounds is critical for the safety and health of patients, employees, and those visiting these facilities. Zandair Air Purification equipment offers the best in hospital air purifiers and medical laboratory purification systems. 

Infection Control Today (ICT)  October 12, 2012 Newletter article "Superbugs Ride Air Currents Around Hospital Units" addresses the issue of airborne pathogens in Hospitals. 

Hospital superbugs can float on air currents and contaminate surfaces far from infected patients’ beds, according to University of Leeds researchers. The results of the study, which was funded by the Engineering and Physical Sciences Research Council (EPSRC), may explain why, despite strict cleaning regimes and hygiene controls, some hospitals still struggle to prevent bacteria moving from patient to patient.

It is already recognized that hospital superbugs, such as MRSA and C. difficile, can be spread through contact. Patients, visitors or even hospital staff can inadvertently touch surfaces contaminated with bacteria and then pass the infection on to others, resulting in a great stress in hospitals on keeping hands and surfaces clean.

1E206EC17FE8461BB0F3BABE47D4C96B resized 600

But the University of Leeds research showed that coughing, sneezing or simply shaking the bed linens can send superbugs into flight, allowing them to contaminate recently cleaned surfaces.

PhD student Marco-Felipe King used a biological aerosol chamber, one of a handful in the world, to replicate conditions in one- and two-bedded hospital rooms. He released tiny aerosol droplets containing Staphyloccus aureus from a heated mannequin simulating the heat emitted by a human body. He placed open petri dishes where other patients’ beds, bedside tables, chairs and washbasins might be and then checked where the bacteria landed and grew.

The results confirmed that contamination can spread to surfaces across a ward. “The level of contamination immediately around the patient’s bed was high but you would expect that. Hospitals keep beds clean and disinfect the tables and surfaces next to beds,” says Dr. Cath Noakes, from the University’s School of Civil Engineering, who supervised the work. “However, we also captured significant quantities of bacteria right across the room, up to 3.5 meters away and especially along the route of the airflows in the room.”

“We now need to find out whether this airborne dispersion is an important route of spreading infection,” adds co-supervisor Dr. Andy Sleigh.

The researchers are hoping that computer modeling will help them determine the risk. The findings have been compared to airflow simulations of the mock hospital rooms and the research team have shown that they are able to accurately predict how airborne particles can be deposited on surfaces.

“Using our understanding of airflow dynamics, we can now use these models to investigate how different ward layouts and different positions of windows, doors and air vents could help prevent microorganisms being deposited on accessible surfaces,” says King.

The international design and engineering firm Arup, which designs hospitals, part sponsored the study. Phil Nedin, director and global healthcare business leader at Arup, says: “We are looking at healthcare facilities of the future and it is important that we look at key issues such as infection control. Being involved in microbiological studies that inform airflow modeling in potentially infectious environments allows us to get a clear understanding of the risks in these particular environments.”

The paper, “Bioaerosol Deposition in Single and Two-Bed Hospital Rooms: A Numerical and Experimental Study,” was published in the journal Building and Environment.

This research is funded by an EPSRC Challenging Engineering grant held by Dr. Cath Noakes. Marco-Felipe King’s PhD was also partially sponsored by Arup.

Reference: M.F. King, C.J. Noakes, P.A. Sleigh, M.A. Camargo-Valero. Bioaerosol Deposition in Single and Two-Bed Hospital Rooms: A Numerical and Experimental Study. Building and Environment. 2012.

Source: University of Leeds

Topics: air filtration purification, MRSA, c-diff, infection control, airborne infections, MRSA airborne, Volatile Organic Compound

Air Quality App Available for Your Smartphone

Posted by Jean Shaw-Leonard on Jul 24, 2012 4:04:00 PM

We are bombarded daily with new apps available for Smartphones and I find this one particularly useful for those with asthma and other illnesses affected by air quality. The American Lung Association has created an easy tool that can give you a quick “heads up” before you head out when the air quality outside is harmful – and it’s free!

Despite continued improvements in improved air quality across the country, unhealthy levels of air pollution still exists across the nation. The American Lung Association has created a new State of the Air® smartphone application, a life-saving resource for people living with lung disease like asthma and chronic obstructive pulmonary disease (COPD), people with heart disease or diabetes, as well as older adults and children.

The State of the Air® app enables users to enter their zip code or use the geo-locator functionality to get current and next-day air quality conditions. The app also provides levels of both ozone and particle pollution, and pushes out alerts if local air quality is code orange or worse. Depending on the severity of the day’s air pollution, the app will provide vital health recommendations – advising that outdoor activities should be rescheduled or that people who work outdoors should limit extended or heavy exertion.

This air quality information is based on data made available to the public by the U.S. Environmental Protection Agency (EPA). The American Lung Association app is available for free download in two leading Smartphone markets, or at www.lung.org/stateoftheairapp.

It is equally important to have good air quality indoors. No matter how well you maintain your office or your home, the air you breathe can be filled with air pollutants, dust particles, mold spores, dander, pollen, dust mites, cleaning chemicals, exhaust fumes, carbon monoxide, viruses and bacteria. Add to these culprits the chemical irritants lurking about in carpets, behind walls, and in the cleansers and waxes used to keep your homes and offices clean. All these can have a direct influence on your health.

The ZAND-AIR™ Air Purification Systems deliver the clean air you need. The key to effective air filtration of damaging volatile air compounds is in the Photo-Catalytic-Oxidation

Indoor Air

The chemical compounds become highly reactive when exposed to a specific wavelength of ultraviolet light, which does not produce any ozone;  to the contrary, it destroys any ambient ozone. The photo-catalyst attracts pollutants and converts them into benign compounds such as water (H2O) and carbon  dioxide (C02).

Explore each of our best air purifier systems in more detail and decide which system will produce the superior results you deserve.


Topics: air filtration purification, Volatile Organic Compound, VOCs, Air Quality, asthma

Frequently Asked Questions About Our Air Purification Systems

Posted by Jean Shaw-Leonard on Jun 22, 2012 11:02:00 AM

Air purification/filtration systems can be very useful in eliminating airborne pathogens. Clean indoor air can reduce the amount of time and money spent on doctor office visits. Air purification/filtration systems come in many sizes and shapes and vary greatly in cost and effectiveness. The questions below hopefully are some you may have and hopefully provide you with answers about ZAND-AIR™ air purification /filtration systems

1. How does your system really work?

ZAND-AIR™ air purification/filtration systems use Photocatalytic Oxidation. In these air purification/filtration systems, Titanium Dioxide (TiO2) is a semiconductor photocatalyst with a band gap energy of 3.2 eV. When the material is irradiated with photons (UV) at less than 385 nm, the band gap energy is exceeded and an electron is promoted from the valence band to the conduction band. This creates molecular holes and instability of the molecule evidenced by hydroxyl radicals (OH). This instability promotes the molecule to find stability which includes attacking with these free radicals organic compounds including micro-organisms. This molecular phenomenon permanently destroys microbes. The term we use is Hydroxyl radicals or superoxide ions.

2. How fast does this occur with moving air?

In the ZAND-AIR™ air purification/filtration systems, the actual molecular chemical reaction happens in a few femtoseconds. (A femtosecond is to a second, what a second is to about 31.7 years) Immediately!

However, remember that the process does not clear the air in one pass. As the validation charts show it takes repeated passes through the system to significantly reduce the VOC’s and all aerobiological microbes.

3. How much air volume does the typical ZAND-AIR PCOC™3?

One ZAND-AIR PCOC™3 air purification/filtration systems unit can handle between 200 cfm and 2,000 cfm. If the total demand is higher than 2,000 cfm additional units can be mounted in a parallel setting.

4. What is the static pressure drop of the unit?ZAND-AIR PCOC™ 3

The open structure of the honeycomb grid creates less than ¼ inch water column. This can be improved further if the MERV-13 filter need not to be used due to prior filtration present in the airstream.

5. We have all been taught in filtration. How does the ZAND-AIR™ PCO interact with HEPA, ULPA, and MERV rated filters?

Filters of all types and designs will always be required. The problem with filters is that they do not filter out VOCs. The VOC molecules are too small. Molds, spores and most bacteria are held within the filter, however having said this you all know the risk and difficulty of replacing loaded filters. We have seen HEPA filters that have bacterial and mold growing on the surface of these filters. Filters are used to protect the units and absorb chemically active compounds.

6. How do molds get into buildings?

Molds enter buildings often by outside air. When mold spores are in the right environment they grow and flourish. Darkness and dampness inside HVAC units can be a great place to grow them. Often they are spread by air passing through these units and blowing spores out vents only to land on surfaces and grow yet more mold, mildew and fungus as well as being inhaled by employees, patients, and customers. Inhaling mold spores and fungi can result in allergies and illness; the term “sick building syndrome” can result. Symptoms may include irritated eyes, nose, and throat and in more severe cases damage to or impaired functions of nerve tissue, skin irritations, and other nonspecific hypersensitivity reactions.   

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Topics: air filtration purification, air filtration, photocatalytic oxidation, TiO2, VOCs

What are Volatile Organic Compounds?

Posted by Jean Shaw-Leonard on Jun 21, 2012 3:34:00 PM

What are volatile organic compounds?  Wikipedia states, “Organic compounds are any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon” Volatile organic compounds are those that can affect where you live and your health.  Most of our time is spent indoors and therefore this definition will apply to indoor volatile organic compounds.  Most often the indoor environment has higher concentrations of bacteria, viruses, and volatile organic compounds (VOCs) than outdoors.  Volatile organic compounds are not often toxic but can cause many serious ill affects to human and animal health.

Man made volatile organic compounds (anthropogenic) sources, like solvents, in particular paints and protective coatings are among the most common volatile organic compounds due to the fact over 12 billion liters are produced each year. 

Volatile Organic Chemical

Some other examples of volatile organic compounds are wax, cleaning products, cosmetics, varnishes, fuels, acetones, disinfectants, pesticides, glues, and adhesives.   Office machinery like printers and copiers use chemicals that release volatile organic compounds and can cause a myriad of ill symptoms for those trapped indoors in close proximity to the of

Volatile organic compounds can cause respiratory problems like runny nose, sneezing, asthma, itchy watery eyes, headache, fatigue and nausea.  More serious side effects can include liver and kidney damage, problems with the nervous system, or even cancer. These are just some of the possible problems with poor quality indoor ambient air.fice machinery.  After new offices are built or buildings are remodeled volatile organic compounds come from carpets, new furniture, and other building materials.  Sick building syndrome can result from these highly concentrated volatile organic compounds.   

It is essential that proper ventilation as well as air purification and filtration are part of the air conditioning system in these buildings to prevent ill side effects and other human or animal health hazards.  The indoor ambient air should be safe for employees, employers, patients, animals, and visitors.

Using photocatalytic oxidation in air purification is one way to significantly reduce volatile organic compounds as well as malignant microbes in the indoor ambient air. 

We at ZandairTM   use this technology in our air purification and filtration systems.   Look through our website and learn more about photocatalytic oxidation and how it can help you have cleaner indoor ambient air.   
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Topics: photocatalytic oxidation, Volatile Organic Compound, VOCs

Best Air Purifier for Your Industry

Posted by Joan Howell on Jan 18, 2012 2:28:00 PM

What is the best air purifier for your industry?  Are you in healthcare, eldercare, IVF industry, cancer treatment centers, childcare, or even farming?  Are diseases, infections, or allergies a serious problem or concern?   No matter your area of expertise -- malignant microbes can have a huge impact on your operations cost, reputation, employees, mortality rate, and overall success of your industry.   Most of the attention for “cleaning up” the problems of ramped disease and infection are focused on washing hands and cleaning and sanitizing surfaces and equipment.  These are essential protocols in reducing malignant microbes in the indoor environment.  But is it enough?    The impact of indoor air is all too often underestimated but can be a major contributor of the distribution of malignant pathogens throughout a facility.    

Air filtration is being utilized in many of the industries mentioned above but what about those pathogens that are too small to be filtered out.  So what are the options to having cleaner air?  Why not step it up a bit and purify the air and destroy the germs.  What is the best air purifier?

Photocatalytic oxidation is the proven technology that does destroy airborne pathogens.  Why not have the best air purifier for your industry?   When the combination of washing hands, cleaning and sanitizing surfaces and equipment and using the best air purifier to clean up the indoor environment are used malignant microbes can be significantly reduced, operations costs decrease, lives of patients and employees are saved, and the individuals medical expenses will be reduced.  Having the best air purifier is one other important aspect of running a successful and efficient industry.

Topics: air filtration, photocatalytic oxidation

U.S. Infection Prevention Product Demand Will Increase

Posted by Joan Howell on Jan 16, 2012 3:12:00 PM

http://www.infectioncontroltoday.com/news/2011/12/us-demand-for-infection-prevention-products-to-rise-51-percent-annually-through-2015.aspx infection prevention

Infection prevention is and continues to be a major concern in the United States and throughout the world.  MRSA, VRE, and C-diff are at the top of most everyone’s list currently of malignant microbes that need to be eradicated in the hospital and healthcare environment.  This article states due to…” stepped-up efforts by medical providers to reduce the incidence and mortality of healthcare-associated infections,…” that there will be in increase in the demand for infection prevention products.

Hospitals and other healthcare establishments are adopting stricter standards…” This is exciting news for the infection prevention product industry, but the patients, visitors, and medical staff are the ones that will benefit most from higher standards.

“Patient and staff hygiene and protection, facility cleaning and disinfection, device and instrument sterilization, and medical waste collection and disposal” the article states, will be the main focus of higher standards. 

Education of engineers that design and build hospitals and healthcare facilities is extremely important.  The infection prevention begins from the ground up.  MRSA, VRE, and C-diff are all airborne.  Designing and installing air purification and filtration can significantly reduce airborne pathogens thereby reducing the amount of surface, staff, and patient contamination.  An infection prevention product such as air purification using photocatalytic oxidation can destroy airborne malignant microbes.  Air purification combined with strict hygiene by medical staff, surface cleaning and sterilization saves lives and reduces costs for the facilities, and patients.

Topics: air filtration purification, photocatalytic oxidation, infection prevention

MRSA Airborne Strikes Again, This Time in Belen

Posted by Joan Howell on Jan 16, 2012 11:08:00 AM

http://www.koat.com/health/30183171/detail.htmlMRSA airborne

MRSA airborne has affected the Belen High School in New Mexico.  They have cleaned the gym over and over again but seem to still be having outbreaks.  They are concerned that many of the students are not taking home their change of clothes and washing them frequently enough.  12 students have reported having staph infections.  The school was concerned they had not warned parents soon enough. 

MRSA airborne is just that “airborne”.  Too many people think you can only get it from direct contact from another infected individual; this is the most common way to become infected with these insidious bacteria.  However, touching surfaces, wearing clothes, or using towels  or even soap or deodorant that have come in contact with an infected person or the bacteria that has settled on a surface can also infect others with  MRSA airborne

When patients enter hospitals many are swabbed for MRSA in their nostrils.  How did it get into their nostrils many may inquire?   Would airborne MRSA be too much for us to deal with in our hospitals, clinics, laboratories, schools, gyms and any other place of assembly?

A quote from research done in 2001 in Japan it states, “In this study, it was confirmed that MRSA could be acquired by medical staff and patients through airborne transmission.”1
So why doesn’t anyone talk about this? It is not anything recently discovered. We are talking ten years ago.  Be sure to think about Photocatalytic Oxidation air purification along with all the other cleaning/sanitation practices currently used to reduce the spread of MRSA airborne. 


1. "Significance of Airborne Transmission of Methicillin-Resistant Staphylococcus aureus in an Otolaryngology–Head and Neck Surgery Unit" by Teruo Shiomori, MD, PhD; Hiroshi Miyamoto, MD, PhD; Kazumi Makishima, MD, PhD. Arch Otolaryngol Head Neck Surg.2001; 127:644-648

Topics: air filtration purification, photocatalytic oxidation, MRSA airborne

Airborne Infections in Nursing Homes

Posted by Joan Howell on Jan 12, 2012 11:03:00 AM

Airborne Infections in Nursing Homes is of great concern to the staff, patients, and lovedairborne infections ones.  When a person is unable to care for themselves independently and family members are overwhelmed, unprepared, or unable to give the kind of care their loved one needs to insure a good quality of life a Nursing home may be the best alternative.  When deciding which long term care facility would best fill the needs of the individual one concern that may not be in the forefront is airborne infections.   While overall physical appearance of a nursing home is extremely important it is what you cannot see that perhaps can be the most critical element for the physical health of the employees, caretakers, and residents.   The potential infectious pathogens in the ambient air can be a major source of infection and disease in long term care facilities.

 “Almost as many nosocomial infections occur annually in nursing homes as in hospitals in the United States1 (Haley et al 1985).

Potential airborne infections in Nursing Homes include viruses such as Adenovirus, Coronavirus, Coxsackievirus, Influenza, Metapneumovirus, Norwalk virus, Parainfluenza, Rhinovirus, Rotavirus, and RSV.  The sources of most of these are humans. Norwalk virus and Adenovirus are said to be from the environment. All of these along with many bacteria are listed in Wladyslaw Kowalski's book 'Hospital Airborne Infection Control' page 218.  Some of the more common bacteria listed in this book are MRSA, Streptococcus pheumoniae, Mycobacterium tuberculosis and VRE.

Filtering and purifying the air in hospitals and nursing care facilities is of vital importance to the overall health and well being of caretakers as well as patients or residents.  Photocatalytic Oxidation is one of the best technologies utilized for air purification.

1. Hospital Airborne Infection Control; Wladyslaw Kowalski

Topics: MRSA, c-diff, airborne infections, viral influenza, elder care