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Extra Protection From The Coronavirus With A UV Air Purifier

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Global concern about the Coronavirus has been rising with an increasing number of cases getting diagnosed in the United States. Officially named COVID-19, the recent outbreak originated in China and has struck down thousands of people across the globe. The United States is no exception, experiencing a rapid increase in diagnoses and fallen victims across the nation.

The rapid extent of Coronavirus can be attributed in part to the fact that some of the people affected are asymptomatic. When others are exposed to these people, chances are, they do not realize it and neglect to take proper precautions as a result. This gives the disease a dangerous advantage.

The Centers For Disease Control (CDC) recommends taking preventive actions that include:

  • Avoid touching your mouth, nose, and eyes.
  • Wash your hands with soap and water frequently, for at least 20 seconds at a time.
  • Use a wipe or household cleaning spray to disinfect and clean objects you touch on a regular basis.

Given the widespread and potentially serious implications of COVID-19, you should not entrust your health and that of your family and employees to hygiene alone. UV Air purifiers can help ward off Coronavirus and are being used in some hospitals that are treating patients with the illness.

Purchase One Of Our Coronavirus UV Air Purification Solutions Now!

The EPA’s, A Brief Guide to Mold, Moisture, and Your Home

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Molds are part of the natural environment, and can be found everywhere, indoors and outdoors. Mold is not usually a problem, unless it begins growing indoors. The best way to control mold growth is to control moisture. This website provides guidance about mold and moisture for homes, schools, multifamily and commercial buildings. Molds can have a big impact on indoor air quality.

Learn about Mold

magnifying glass over the word mold
Learn about mold growth indoors, including topics like:

Resources for Health Professionals

Mold resources for health professionals
Find useful resources to gain more technical knowledge and to help you connect with your audience about mold and indoor air quality.

Schools and Commercial Buildings

Mold information for schools and commercial buildings
Learn about mold growth in schools, including topics like:

EPA The Key to Mold Control is Moisture Control https://www.epa.gov/mold

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Molds are part of the natural environment, and can be found everywhere, indoors and outdoors. Mold is not usually a problem, unless it begins growing indoors. The best way to control mold growth is to control moisture. This website provides guidance about mold and moisture for homes, schools, multifamily and commercial buildings. Molds can have a big impact on indoor air quality.

Learn about Mold

magnifying glass over the word mold
Learn about mold growth indoors, including topics like:

Resources for Health Professionals

Mold resources for health professionals
Find useful resources to gain more technical knowledge and to help you connect with your audience about mold and indoor air quality.

Schools and Commercial Buildings

Mold information for schools and commercial buildings
Learn about mold growth in schools, including topics like:

Particles and their size in microns

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Common Particles and
Their Sizes in Microns

Did you know?…The average home collects about 2 POUNDS OF DUST PER WEEK!

Particles are commonly measured in microns, a metric unit of measure.
There are 25,400 microns in one inch.
This dot (.) is approximately 1/64 of an inch wide and equals 615 microns.


Common Items and their respective particle sizes:

Postage Stamp, 1 inch high 25,400 microns
Eye of a Needle 1,230 microns
Human Hair 40 to 300 microns
Oil Smoke 0.03 to 1 micron
Fertilizer 10 to 1000 microns
Tobacco Smoke 0.01 to 1 microns
Coal Dust 1 to 100 microns
Beach Sand 100 to 2000 microns
Mold Spores 10 to 30 microns
Pollens 10 to 1000 microns
Typical Atmospheric Dust 0.001 to 30 microns


Particles 101: Did You Know?…

– Visible particles constitute only about 10% of indoor air!

– Particle visibility depends on the eye itself. In other words, light intensity and quality, background and particle type.

– Particles on furniture and those in a shaft of light are approximately 50 microns or larger.

– It may be possible to see particles as small as 10 microns under favorable conditions.

– The majority of harmful particles are 3 microns or less in size.

– Particles of 1 micron or less adhere to surfaces by molecular adhesion. Scrubbing is generally the only way to remove them.

– Larger particles tend to settle out of the atmosphere due to weight.

– Smaller, “respirable” particles remain virtually suspended in the air until breathed in.

– Approximately 98-99% of all particles by count are in the size range of 5 microns or less. These particles tend to remain in suspension or settle out so slowly that only quality electronic air cleaners and HEPA air cleaners are effective in removing these particles.

– The average person breathes in about 16,000 quarts of air per day. Each quart contains some 70,000 visible and invisible particles. That’s over a billion particles per day that our lungs have to filter out!

– The average home collects about 2 pounds of dust per week!

– A 9′ x 12′ carpet or rug will collect an average of about 10 pounds of dust per year!


Sizing chart in microns for bacteria, spores, viruses, smoke, pet dander, & dust


You Owe It To Yourself To Breathe Clean Healthy Purified Air


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Control dust, mold, odor, pollen, allergy, and virus.

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About Mold / Mold Facts    Why Chlorine Bleach is Not Effective in Killing Mold

Indoor Air Quality – What You Should Know    Effects of Negative Ions

Indoor Air Quality- What You Should Know

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Indoor Air Quality – What You Should Know

    Based on studies by the Environmental Protection Agency (EPA), billions of dollars are spent annually for medication to help Americans breathe or cure their respiratory illnesses. Eleven million Americans have asthma. Twenty-eight million have hay fever and other allergies. Physicians are now discovering that the solution to the problems of many of these people is not in medicine but in reducing the pollutants in the air they breathe.

    Every year at least 6,000 new chemical compounds are developed. Many are used indoors every day, at home and at work. Add to these pollutants the mold, mildew, bacteria, viruses, tobacco smoke, grease, pollen, dirt, asbestos, lead and numerous other contaminants that can affect our breathing and our health. Then allow them to circulate in today’s nearly airtight indoor environment. No wonder our indoor air is, on average, two to ten times as polluted as the worst outdoor air.

    Viruses and bacteria that thrive in the ducts, coils, and recesses of building ventilation systems have been proven to cause ailments ranging from influenza to tuberculosis. Some HVAC systems have been found to contain up to 27 species of fungi.

    Based on information given at the First Annual Air Quality convention sponsored by EPA, April 1992, Tampa, Florida:

  •  40% of all buildings pose a serious health hazard due to indoor air pollution, according to the World Health Organization.
  •  EPA estimates an 18% annual production loss to American business due to poor indoor air quality.
  • 20% of all employees have a major illnessrelated to indoor air pollution such as allergies, asthma, auto-immune diseases, etc.
  •  EPA says high levels of formaldehyde cause cancer
  • Scientists now recognize that pollutants, even at acceptable concentration, combined together in an indoor environment have a synergistic negative effect.

Indoor Air Quality and Ozone

    The air we breathe is made up of mostly oxygen and nitrogen. Ozone can be made from common oxygen and high electrical discharge (as in a thunderstorm). The high voltage discharge (also known as corona discharge) breaks the two oxygen (O2) atoms apart. These oxygen atoms are extremely reactive and they recombine in groups of three with the resulting molecule being called Ozone (O3) or trivalent oxygen. When this highly reactive O3 molecule floats in the environment it actively seeks out pollutant molecules. One of the atoms from the O3 molecule will attach itself to the pollutant molecule and destroy it.

    This highly reactive quality of ozone is why it is such a powerful and efficient cleaner and purifier. Ozone will react with almost anything, including chemical sources of unpleasant or hazardous indoor odors. Bacteria, mold and mildew, pet odors, many cooking odors, etc., are destroyed when they react with ozone. Like chemical pollutants, the membranes or shells of bacteria contain unsaturated molecules which are destroyed by ozone. Without its protective membrane or shell, the bacterium dies, leaving only oxygen. The same applies to viruses and fungi.

One of the most important properties of ozone is that it has a very short life span. This life span is called a “half-life”. The half-life of ozone is approximately 20-30 minutes. This means that half of the ozone created will break down and return to oxygen in approximately 20-30 minutes depending on temperature, humidity and the amount of contaminants in the air or on surfaces that the ozone has to counteract. In other words, strong odors or pollutants will use more ozone and light odors will require less. If ozone can not find a contaminant to work on, it simply reverts to oxygen.


Ozone can be effective against*

Chemicals Combustion Germs Odors
Cooking Odors Garbage Odors Menthol Onions
Hospital Odors Sewer Gases Asphalt Fumes Butane
Aged Manuscripts Cigarette Smoke Exhaust Fumes Food Odors
Creosote Garlic Mildew Paint Odors
Industrial Wastes Toluene Bacteria Poultry Odors
Dead Animals Gasoline Fecal Odors Carbon Monoxide
Kerosene Viruses Mold Fungi
Algae Acrylic Acid Bathroom Smells Propane
Decaying Odors Formaldehyde Fertilizer Tetrachloride
Lactic Acid Adhesive Gases Moth Balls Furniture Odors
Ammonia Coal Smoke Benzene Rancid Oils
Diesel Fumes Carbolic Acid Fire Odors Carpet Odors
Lubricating Oils Alcohol Naphtha Gangrene
Animal Odors Ethyl Alcohol Body Odor Resins
Ether Anesthetics Fish Odors Charred Materials
Medicinal Odors Flood Odors Nicotine Burned Food Odors

* This is only a short list of the things ozone can effect.

Negative Ions Pollutants and Health

    Ionization or negative ion generation is often referred to as the “thunderstorm effect”. It is well known that prior to a thunderstorm, animals and even many humans feel nervous, jittery and irritable; however, after the storm there seems to be a feeling of calm. Both animals and humans experience this phenomena. Most people can not explain this renewed sense of well-being. However, there is a logical explanation. All of this is due to the amount of negative ions in the air around us.  Prior to a thunderstorm there is a very high concentration of positive ions in the air. These tend to be pollutants such as dust, bacteria, pollen, chemicals, etc. The storm releases electrical discharges consisting of high concentrations of negative ions. Negative ions destroy many of these air pollutants and, therefore, give us a sense of well being. When relatively too many positive ions are present in the air before a storm, the positive charge is transferred in the air you breathe from your lungs to the blood, causing the blood platelets to release a hormone that quite strongly affects your moods, your joints, and other physiological functions in your body.

Ions are floating in the air around us all the time and have either negative or positive charges on them. Changes in their concentration, or in the ratio of positively to negatively charged molecules can have remarkable effects on plants and animals. It is known in science that ion depletion is the source of a wide range of human health problems, both mental and physical. Air ions are important to you because if there are a high proportion of negative ions you will feel lively, uplifted, and enthusiastic. Too many positive ions will have you feeling depressed, lethargic and full of aches, pains and complaints. In general, exposure to negatively ionized air has been shown to increase oxygenation of the lungs, vital capacity, and ciliary activity. All types of beneficial responses take place as a result of these friendly ions. (Effects of Negative Ions)

    Fortunately through modern technology it is possible to control the electrical state of our indoor environments by generating negative ions back in the air. These negative ions attach themselves to airborne toxins and drop them to a surface. Ions basically take out the larger pollutants in the air. For example, ozone will take the smell of smoke out of the room and neutralize the chemicals, but will not remove the smoke itself. Negative ions take the smoke out.

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About Mold / Mold Facts    Particles and their size in microns

Why Chlorine Bleach is Not Effective in Killing Mold

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Bio-Fighter Replacement UV Lamps

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Ultraviolet Light Air Cleaners / Germicidal UV Air Purifiers
Welcome to UV Air Purifiers Info;  UV / Germicidal UV light and UV air purifiers sanitizers

Bio-Fighter Replacement Bulbs / Germicidal UV lamps

Replacement Genuine OEM UV-C Lamps for Dust Free Bio-Fighter LightStick, Triad HO, Nomad, Lennox Plus, and all other Dust Free Bio-Fighter UV Light Systems. The life of the UV lamp is 9000 hours / 375 days. Even if it still burns after 9000 hours it looses it’s UV eradication power and should be replaced. Optional Ozone is available on the LightStick, Triad, and the VersaLight models.

Bio-Fighter UV-C Light Systems

Mounts in the duct system to control harmful bacteria, viruses, yeast, and mold, where they start, in the HVAC system. Superior technology and quality control, the Bio-Fighter germicidal ultraviolet light systems provide you the performance to solve your indoor air quality problems. The germicidal ultraviolet light systems are available in several models and configurations from residential to industrial.

Germicidal UV light kills mold, viruses, and bacteria
UV Air Purifiers Offer Asthma and Allergy Relief

What is Mold?, About Mold, Mold Facts    Why Chlorine Bleach is ineffective in Killing Mold

UV disinfection systems, (Germicidal Ultraviolet Light), commercial and residential UV air purifiers, literally sterilize microorganisms. UVC reduces or eliminates germs such as mold, viruses, bacteria, fungi, and mold spores from the indoor air of homes, offices, basements, commercial buildings, Heating Ventilating and Air Conditioner Systems, ensuring a much better indoor air quality.
UV light has been proven for decades to effectively disinfect air, surfaces and water. UV air cleaners can help your family, students or employees live, work or study in a healthier environment, especially  sufferers from allergy, asthma, and or other respiratory diseases.

Standard Air purifiers have a fundamental flaw. They rely on air being pulled through the unit in order to clean it. This creates an ineffective, high energy cost air purifier. UV air purifiers utilize a new generation of technology. UV technology does not reply on filters or air passing through the air purifier. This technology simply produces a blanket of redundant oxidizers that not only clean your air, but sanitize surfaces as well eliminating the pollutants.

What does a UV light do?
A germicidal UV light system can significantly reduce the amount of viable airborne micro-organisms found on surfaces, in the air, and in HVAC units. UVC eliminates molds, bacteria, yeasts, and viruses. These are naturally occurring contaminants that infiltrate every home and office on this planet. Micro-organisms are living creatures that are so small a microscope is required to view them. HEPA air cleaners are efficient enough to capture many molds and bacteria, but the micro-organisms remain alive, continuing to grow and reproduce directly on the filtration media.

What are the primary benefits? UV-C light will significantly reduce the amount of microbials in ductwork and air space, helping to reduce possible health problems associated with inhaling microbials. UV-C light is also beneficial in keeping HVAC coils free of mold which increases system efficiency.

What is the importance of UV-C light products for indoor environments?
Overall, people spend 90% of their time indoors, in a “closed” environment with little or no exchange of outside air. Such an environment can become a breeding ground for potentially harmful pathogens, and in high numbers, can prove hazardous to human health.

What is UV light?
UV stands for Ultra-Violet light. Ultraviolet light represents the frequency of light between 200 nanometers (nm) and 400nm and cannot be seen with the naked eye. Within the UV spectrum lie three distinct bands of light: UV-A, UV-B, and UV-C. Longwave UV light (315nm to 400nm), or UV-A, refers to what we commonly call “black light.” UV-B (280nm to 315nm), or midrange UV, causes sunburn. Germicidal UV light (200nm to 280nm), or UV-C, is effective in microbial control. Research has demonstrated that within this UV-C band the most efficient frequency for microbial destruction is between 254nm and 265nm. Germicidal lamps that produce the majority of their output in this range will be the most effective in microbial control/destruction.

How does ultraviolet light work?
UV-C light penetrates the cell walls of the microbe, causing cellular or genetic damage. The affected microbe is neutralized or becomes unable to reproduce. Intensity and exposure time will determine how quickly a susceptible microbe is disabled by UV-C light.
Ultraviolet light possesses just the right amount of energy to break organic molecular bonds. As micro-organisms pass by the UV rays radiated from the ultraviolet lamp, this bond breakage translates into cellular or genetic damage for micro-organisms, such as germs, viruses, bacteria, fungi (like molds), etc. This results in the destruction of the micro-organisms.

Do I still need an air filter?Yes and no. Stand alone purifiers may or may not have filters. An induct UV light system is designed to be used in addition to a dust filter or electronic air cleaner and the filtration of dust particles will also aid in keeping the bulb(s) of the UV light system clean. However, filters are inefficient at dealing with microscopic bacteria, molds, and viruses and are incapable of preventing mold from growing on a surface. A UV-C Light System contributes significantly to the reduction of the small microbial organisms that pass through filters and into the general air stream. Proper placement of a UV light system above the coil, or a surface area prone to microbial growth aids in reducing the amount of viable microbes on that surface.

How long do the lamps last? The Surround Air and Dust Free Bio-Fighter UV-C light bulbs have a service life of 9,000 hours, or approximately 375 days. Annual replacement of the bulb(s) is recommended. Most UV-C light systems should be left on continuously as turning them on and off ages the bulbs and power supplies.

How much electricity does induct UV-C light use?Each tube uses approximately the same electricity as a 40-watt light bulb.

How many lamps do you recommend for induct home installations?One lamp is normally sufficient to control microbial growth on the coils and in the drain pan. The lamp size used should be proportional to the space that is available in the coil and drain pan area. However, since each HVAC system is as different as the building within which it functions, the UV-C Light System most suitable for your needs should be recommended and installed by a professional trained in UV-C light use and application.

Why should I consider installing a UV light?
Indoor air can be some of the poorest quality air we experience. When we leave our windows shut, air is constantly recirculated throughout our homes. Over time this air can become stagnant and bacteria, molds, yeasts, and viruses more concentrated. These concentrations can cause inflammation of mucous membranes, upper respiratory problems, and aggravate asthma and other breathing ailments. A germicidal UV light system assists in combating high levels of these micro-organism concentrations.

Could you benefit from healthier air? Yes. Poor indoor air quality is a problem that affects everyone. Individuals with weakened immune systems, allergies, and asthma benefit the most from improving air quality. Households with children or elderly individuals will also benefit from the improved air quality.
Your HVAC air handling system can operate with more efficiency as the coils, drain pan, and ductwork stay cleaner longer.

Bio-Fighter Germicidal Replacement UV Bulbs    Bio-Fighter UV Systems

What is Mold?, About Mold, Mold Facts    Why Chlorine Bleach is ineffective in Killing Mold

UV Air Purifiers Offer Asthma and Allergy Relief

An Effective Germicidal UV Air Cleaner
The stuff floating in the air is 80% dead skin and over 350 different allergy producing air pollutants and contaminants, including cigarette, cigar and pipe smoke, germs, bacteria, viruses, mold, mildew and fungi, pollen, house dust and dust mites, odors from smoke, pets, mold, (About Mold, Mold Facts), mildew, exhaust fumes, food, body sweat, chemical gases (formaldehyde, benzene, etc.) from new carpets, furniture, cleaning products, solvents, furnishings, dry cleaning and construction.

Easy Breathing with UV Air Purifiers
The effects of breathing this allergy producing air pollution include dizziness, irritability, coughing, sneezing, dry eyes, hay fever, allergies, asthma symptoms, sinus problems, ear infections, depression, fatigue, headaches, nausea, breathing problems, respiratory infections, etc.

Healthier Employees with UV Air Cleaners
In fact, according to the Environmental Protection Agency:

  • 20% of all employees have a major illness related to indoor air pollution such as allergy, asthma, autoimmune diseases, etc.
  • Billions of dollars are spent annually for medication to help Americans breathe or cure their respiratory illnesses.
  • EPA estimates an 18% annual production loss to American business due to poor indoor air quality.

UV Facts – Germicidal UV Light
About Ultraviolet (UV) Light Used for Air Disinfection by Edward A. Nardell, M. D. Harvard Medical School

What is UV or ultraviolet light? Ultraviolet light is part of the spectrum of electromagnetic energy generated by the sun. The full spectrum includes, in order increasing energy, radio waves, infrared, visible light, ultraviolet, x-rays, gamma rays and cosmic rays. Since UV is not visible, it is technically not “light”, but use of the term “ultraviolet light” is so widespread that, it will be used here. Most sources of light generate some UV. For air disinfection, UV is generated by electric lamps that resemble ordinary fluorescent lamps.
What is germicidal UV?
 This is UV of a specific type (253.7nm wavelength) known to kill airborne germs that transmit infections from person to person within buildings. Germicidal UV is aimed at the upper room air so that only airborne microbes are directly exposed. Room occupants are exposed only to low levels of reflected UV – levels below that known to cause eye irritation. Germicidal UV has been used safely and effectively in hospitals, clinics and laboratories for more than 60 years. UV does not prevent transmission of infections (e.g. colds) by direct person to person contact.
Is UV harmful? We are all exposed to the UV in sunlight. UV exposure can be very harmful, or harmless, depending on the type of UV, the type of exposure, the duration of exposure, and individual differences in response to UV. There are the following types of UV based on the wave length measured in nanometers (nm):
 ultraviolet with wavelength below 200nm is known as Vacuum UV or UV V.
 (200 – 280nm) – Also known as “shortwave” UV, UVC or C-band UV includes germicidal (253.7nm wavelength) UV used for air disinfection. Unintentional overexposure causes transient redness and eye irritation, but does NOT cause skin cancer or cataracts.
UV-B (280 -315nm) – A small, but dangerous part of sunlight. Most solar UV-B is absorbed by the diminishing atmospheric ozone layer. Prolonged exposure is responsible for some type of skin cancer, skin aging, and cataracts (clouding of the lens of the eye).
 (315 – 400nm) – Longwave UV, also known as “blacklight”, the major type of UV in sunlight, responsible for skin tanning, generally not harmful, used in medicine to treat certain skin disorders.

UV Health Facts

Why is UV-B harmful while UV-C (germicidal UV) is not? The difference has to do with the ability of UV rays to penetrate body surfaces. UVC has an extremely low penetrating ability. It is nearly completely absorbed by the outer, dead layer of the skin (stratum corneum) where it does little harm. It does reach the most superficial layer of the eye where overexposure can cause irritation, but it does not penetrate to the top of the lens of the eye and can not cause cataracts. UVC is completely stopped by the ordinary eye glasses and by ordinary clothing.

How much UV exposure is considered safe? The National Institute for Occupational Safety and Health (NIOSH) has established safe exposure levels for each type of UV. These safe exposure limits are set below the levels found to cause eye irritation, eye being the body part most sensitive to UV. For germicidal UV (253.7nm) the irradiance limit is set to 0.2 W/cm.

How can people be certain they are not overexposed to UV? When upper room UV is first installed it must be checked with a sensitive UV meter to make sure reflected UV is less than 0.2 W/cm at eye level. UV air cleaners must be installed well above eye level – usually 7 feet above the floor. UV tubes (lamps) within the air cleaners should not be directly visible from within 30 feet. Safety is assured if UV measurements at eye level meet NIOSH standards.

What are the symptoms and signs of UV overexposure? UV overexposure  causes an eye inflammatory condition known as photokeratitis. For 6 to 12 hours after an accidental overexposure the individual may feel nothing unusual, followed by the abrupt sensation of foreign body or “sand” in the eyes, redness of the skin around the eyes, some light sensitivity, tearing, and eye pain. The acute symptoms last 6 to 24 hours and resolve completely without long-term effects. Overexposure of the skin resembles sunburn but does not result in tanning.

What precautions are needed with overhead germicidal UV? Fixtures must be turned OFF when cleaning, inspecting or changing the lamps. Persons hypersensitive to sunlight may need to wear protective glasses, clothing or use sunscreen on exposed skin. No special protection is needed for most people.

UV Light Air Purifier Facts & Studies

  • The Centers of Disease Control (CDC) recommends the use of ultraviolet light with simultaneous use of HEPA air filters.
  • The U.S. government now specifies that UV light should be used in air handling units to improve indoor air quality in government buildings, by controlling airborne and surface microbial growth.
  • The Air Institute of Respiratory Education suggests UV lights be used in buildings for indoor air quality purposes, and states that may be the final line of defense against those diseases that have developed resistance to drugs, such as tuberculosis and others.
  • According to the Aerobiological Engineering Dept. at Penn State University, the ultraviolet component of sunlight is the main reason microbes die in the outdoor air. The die-off rate in the outdoors varies from one pathogen to another, but can be anywhere from a few seconds to a few minutes for a 90-99% kill of viruses or contagious bacteria.
  • The Centers of Disease Control (CDC) recommends UV lights in homeless shelters to prevent the spread of disease, particularly TB (tuberculosis).
  • A study by Air & Waste Management Association found the combination of a HEPA air filter and germicidal UV lamp reduced bacteria by 80% in a 3072 cubic foot chamber.

Healthier Employees with UV Air Cleaners

The Environmental Protection Agency (EPA) says Indoor Air Pollution
is the number one health problem in America.

The average person spends 90% of his or her time indoors where the air may be 5 to 100 times more polluted than outside air. With a home air purifier electronic air cleaner we can clean your air. We offer air purification systems with a variety of technologies, sizes and designs. Our electronic air cleaner or portable air purifier helps you in poor air quality environments.

In fact, according to the Environmental Protection Agency:

  • 20% of all employees have a major illness related to indoor air pollution such as allergy, asthma, autoimmune diseases, etc.
  • 20% of all employees have a major illness related to indoor air pollution such as allergy, asthma, autoimmune diseases, etc.
  • Billions of dollars are spent annually for medication to help Americans breathe or cure their respiratory illnesses.
  • EPA estimates an 18% annual production loss to American business due to poor indoor air quality.

The House of Representatives has called indoor air pollution our greatest environmental health problem. Some of the most polluted air you breathe isn’t downtown, but inside your home and office! And according to the World Health Organization, 40% of all buildings pose a serious health hazard due to indoor air pollution, know as Sick Building Syndrome.

“According to the World Health Organization (WHO), 60% of IAQ problems and allergies may be mold related.” Source: Air Conditioning, Heating & Refrigeration News, “A cure for the dreaded Dirty Socks Syndrome” April 5, 1999, pp. 24-25.

UV Lamps in HVAC Reduces Worker Sickness
(From HVAC Insider, National Edition, 1st quarter 2004)

In a study published in the Lancet medical journal, Canadian scientists found that by using ultraviolet lamps to kill germs in ventilation systems, worker sickness was reduced by about 20 percent, including a 40 percent drop in breathing problems.

About 70 percent of the work force in North America and Western Europe work indoors, and have frequently unexplained health problems such as irritation of the eyes, throat and nose, as well as respiratory illnesses.

Ultraviolet germicidal irradiation, or UVGI, is sometimes used in hospital ventilation systems to disinfect the air but is rarely incorporated into office or other building ducts because there has been little evidence of a benefit.

In the study, ultraviolet lamps were installed in the ventilation systems of Montreal office buildings near the cooling coils and drip pans. The lamps were turned on for four weeks, then off for 12 week periods for almost a year.

The use of the UV lamps resulted in a 20 percent overall reduction in all symptoms for some workers; and a 40 percent reduction in respiratory symptoms and a 30 percent reduction in mucous problems. With the lights switched on, the frequency of muscle complaints among nonsmokers halved and the incidence of work-related breathing problems among them dropped by nearly 60 percent. The benefits were greatest for workers with allergies and for people who had never smoked.

According to Dr. Dick Menzies, the study’s leader, “Installation of UVGI in most North American offices could resolve work-related symptoms in about 4 million employees, caused by (germ) contamination of heating, ventilation and air conditioning systems.” He also added, “The cost of UVGI installation could in the long run prove cost-effective compared with the yearly losses from absence because of building-related illnesses.”

Physicians are now discovering that the solution to the problems of many of these people is not in medicine but in reducing the pollutants in the air people breathe. But mere filtration is insufficient. Filters only create a breeding ground for pathogens, like molds, bacteria and dust mites and do nothing to combat chemicals or odors.

Medical studies using germicidal ultra-violet air disinfection have proven effective in reducing the spread of tuberculosis, measles, influenza, smallpox, and controlling infection in operating rooms.

“According to the World Health Organization (WHO), 60% of IAQ problems and allergies may be mold related.” Source: Air Conditioning, Heating & Refrigeration News, “A cure for the dreaded Dirty Socks Syndrome” April 5, 1999, pp. 24-25.

“Common bacteria are now so resistant to antibiotics that they can kill.” Source: US News & World Report, “Losing the Battle of the Bugs”, May 10, 1999, pp. 52-60.

UV Lamps Reduce Worker Sickness

This study tested 771 employees in three different office buildings. The UV lights, which were installed in the ventilation system, were operated in three cycles of four weeks on, twelve weeks off. Measurements showed a 99% reduction of germs on irradiated surfaces inside the ventilation system.

During some weeks, there was a 40% reduction in respiratory symptoms, and a 30% reduction in mucous problems in individuals examined. When the lights were activated, muscle complaints among nonsmokers were reduced by 50%, and work-related breathing problems decreased by 60%.

The Environmental Protection Agency (EPA) says Indoor Air Pollution is the number one health problem in America. Peak Pure Air wants you to breathe better!

The average person spends 90% of his or her time indoors where the air may be 5 to 100 times more polluted than outside air. With a home air purifier electronic air cleaner or an indoor air purifier, Peak Pure Air can clean your air. We offer air purification systems with a variety of technologies, sizes and designs. Our electronic air cleaner or portable air purifier helps you in poor air quality environments.

Bio-Fighter Replacement Bulbs    Bio-Fighter UV Systems

Bio-Fighter Nomad & Triad UV Light System Sizing Chart

How TiO2 UV Photocatalytic Oxidation Works  Why Chlorine Bleach is ineffective in Killing Mold

Indoor Air Quality- What You Should Know     Replacement Ozone Filter Plates

While some of our products are designed to remove smoke and odors, we do not claim
they remove all of the harmful effects caused by smoking or second hand smoke.
Product claims and descriptions have been evaluated and approved by the appropriate product manufacturer.

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Alina-Florentina COMĂNESCU1 , Maria MIHALY2 , Aurelia MEGHEA3

Această lucrare prezintă degradarea fotocatalitică a poluanţilor organici (4- clorfenol, 2,4-diclorfenol şi cristal violet) utilizând nanoparticule de NiO şi nanoparticule de NiO îmbrăcate în silice. Degradarea fotocatalitică a poluanţilor a fost investigată în diferite condiţii de reacţie, variind concentraţia de catalizator şi, sursa de iluminare, şi folosind catalizatori activaţi cu radiaţie gamma sau cu NaOCl. Randamentul de degradare fotocatalitică a crescut, prin utilizarea nanoparticulelor pe bază de NiO activate de la 30% la 55%, pentru un timp de iradiere de 6 ore. Originalitatea acestei lucrari este data de utilizarea nanoparticulelor activate cu radiaţie gamma în procese fotocatalitice

This paper presents the photocatalytic degradation of organic pollutants (4- chlorophenol, 2,4-dichlorophenol and crystal violet) using NiO and NiO silica coated nanoparticles. Photocatalytic degradation under different experimental conditions: catalyst loadings, irradiation sources and activated catalysts by using gamma rays and respecctively NaOCl. Catalyst activation was made using gamma radiolysis and NaOCl activation. The photocatalytic degradation yield increased from 30% up to 55% when activated NiO based nanoparticles were used for an irradiation time of 6 hours. Uses of gamma activated nanoparticles as photocatalyst represents the main original issues of this paper.

Keywords: organic pollutants, NiO nanoparticles, photocatalysis, gamma radiolysis, NaOCl activation


In recent years, the use of semiconductor metal oxides as photocatalysts for degradation of pollutants has attracted attention of scientific community. Semiconductor metal oxide nanoparticles have been studied due to their novell optical, electronic, magnetic, thermal and mechanical properties and potential application in catalyst, gas-sensors and photo-electronic devices [1-5]. The most common semiconducting metal oxides are TiO2 and ZnO due to their catalytic

PhD Student, Dept. of Applied Physical Chemistry and Electrochemistry, University POLITEHNICA of Bucharest, Romania 2 PhD Lecturer, Dept. of Applied Physical Chemistry and Electrochemistry, University POLITEHNICA of Bucharest, Romania, e-mail: maria.mihaly@upb.ro 3 Prof., Dept. of Applied Physical Chemistry and Electrochemistry, University POLITEHNICA of Bucharest, Romania, e-mail: a.meghea@gmail.com

activity and stability. Among them, transition metal oxide, NiO appears to be especially efficient as catalyst for wastewater pollution abatement [6-9]. NiO is a p-type semiconductor characterized by a wide band gap between [3.5 eV] valence band [3.1 eV] and conduction band [- 0.5 V] that make it suitable for photocatalytical processes [10-12].

The photocatalytic process starts with the irradiation of a semiconductor material by light with sufficient energy to excite the electrons from the valence band to the conduction band generating extremely reactive electron/hole (e- /h+ ) pairs that migrate to the adsorbed species leading to reactive species such as hydroxyl radicals. The major drawback of the photocatalytic process is the electron/hole pair recombination. To solve this problem metal oxide nanoparticles are embedded into different matrices. The matrix should have an essential influence on the properties of the nanoparticles [13-15]. The most common matrix is silica matrix. The high porosity of amorphous silica materials provides the three dimensional space required for the doping of functional components; moreover they are effective transparent that is unlikely to absorb light in the near-infrared, visible and ultraviolet regions or to interfere with magnetic yields which allows the dopants inside the matrix to keep their optical properties and, finally they are nontoxic as well.

The photocatalytic activity of semiconducting metal oxide can be effectively modified by ionizing radiations. These radiations induce some changes in the structural, textural, electric, magnetic and catalytic properties of the treated solids. For instance gamma-rays have been reported to effect some changes in the chemistry of surfaces of the semiconducting metal oxides [24-28].

On the other hand semiconductor activation with NaOCl induces a higher state of oxidation for the metalic atom. The activity and selectivity of the semiconducting metal oxide depends on the oxidation state of metal ions and their co-ordination in the lattice, the surface action-oxygen bond strength, the content of active oxygen – both total and surface, and the morphology of the material [29- 32].

In this paper the photocatalytic activity of NiO based materials, synthesized by microemulsion assisted sol-gel process was investigated for the degradation of crystal violet (CV) and chlorinated phenols (4-chlorophenol: 4-CP, 2,4-dichlorophenol: 2,4-DCP). The effect of key operational parameters on the pollutants photodegradation process such as catalyst loading, light source and type of catalyst was studied.

The effect of gamma-rays and NaOCl on the photocatalytic activity of NiO based nanomaterials has been investigated. The paper originality is mainly given by the use of activated photocatalysts and by combining gamma-rays activation with photocatlytical process.

  1. Experimental

All chemicals were of the highest purity and were used as received without further purification or distillation: methyl violet (crystal violet), 2,4- diclorophenol, NiO commercial nanoparticles (< 50 nm (BET), >50 m2 g -1 (SSA), density 6.67 g/mL at 25°C (lit.), bulk density 0.51 g/mL) and sodium hypochlorite (6,5%) from Sigma-Aldrich®, 4-CP purchased from Riedel-de Haën® and TiO2 Degussa P25. Ultra-pure water (Millipore Corporation) was used.

The photocatalytic degradation experiments of CV were made by contacting a mass of 20 mg of powder catalyst with 100 mL of 10 mg/L crystal violet aqueous solution, under vigorous stirring in a typical photoreactor equipped with cooling jacket. Samples were irradiated with a 1000 W Xenon lamp (6271H, Oriel) by using a UG filter which transmitted light in the range of 250 – 400 nm (max. 330 nm). The temperature of the experiments was maintained at 20ºC. The colour degradation was estimated by spectral changes of 3 mL aliquots at 3 minutes time interval using a JASCO V-670 Spectrophotometer.

Irradiation in UVA, for chlorophenols degradation, was performed with a laboratory constructed „illumination box” equipped with four F15W/T8 black light tubes (Sylvania GTE, USA). The maximum emission of these tubes is around 375 nm, emitting 71.7 mWcm-2 at a distance of 25 cm.

Pollutant degradation was monitored, after filtration with 0.2 mm filter MILLEX PVDF Durapore-GV Millipore by HPLC, using an HPLC apparatus consisting in a Waters (Milford, MA, USA) Model 600E pump associated with a Waters Model gradient controller, a Rheodyne (Cotati, CA, USA) Model 7725i sample injector equipped with 20 µL sample loop, Lichrospher 100 RP-18 (10 UM) analytical column (25cmx4mm ID) and a Waters Model 486 tunable absorbance detector, set at 280 nm, controlled by the Millenium (Waters) software. The mobile phase was acetonitrile:water (1:1) mixture containing 0.2% acetic acid.

Gamma-radiolysis experiments were performed at room temperature in a 60Co, 6500 Ci Gamma Chamber (4000 A, Isotope Group Bhaba Atomic Research Centre Trombay, India). The irradiation for chlorophenols degradation and gamma radiolysis experiments were performed at the Institute of Physical Chemistry NCSR “Demokritos”, Catalytic-Photocatalytic Processes (Solar Energy Environment) Laboratory in Athens, Greece.

  1. Results and discussion

There are different methods to synthesise NiO based materials reported in the literarature: hydrothermal synthesis [16], microemulsion [17-19], sol-gel methods [20-22], microemulsion assisted sol-gel procedure [13]. Synthesizing NiO based materials by microemulsion assisted sol-gel process presents several advantages: i) the metal oxide nanoparticles are reduced directly in the microemulsion and can be used as a catalyst in suspension without further treatments, ii) the metal oxide nanoparticles size and shape can be controlled to a great extent therefore a narrow particle size distribution can be obtained, iii) the metal oxides nanoparticles are entrapped in the silica network which acts as crystallization nuclei within the microemulsion colloidal aggregates.

3.1. Degradation of pollutants using NiO based materials

3.1.1. Degradation of CV

CV photodegradation experiments were made by comparing the rate of colour degradation of the solution containing the NiO based materials with those possessed by a well known TiO2 photocatalyst. The results are illustrated in Figs. 2-4 and show that NiO based materials have also photocatalytic activity, especially NiO/SiO2 bulk samples. These graphs show that the NiO NP samples have a higher photocatalytic efficiency compared to NiO/SiO2 NP as they have nanometric size 11 nm, respectively 13 nm and a higher specific surface area 85 m 2 g -1, respectively 46,14 m2 g -1 [13].

NiO based materials presents good adsorption properties for crystal violet and these improved the dye photocatalytic degradation.

3.1.2 Degradation of 4-CP

Adsorption test for 4-CP on NiO based materials

In a typical adsorption experiment 10 mL of aqueous 4-CP (15ppm) containing NiO based materials were added to a cylindrical pyrex cell, covered tightly with a serum cap and magnetically stirred, in the dark, at ambient temperature for 240 minutes. Analysis of the poluttant adsorbed was performed after filtration on a 0.2 mm MILLEX PVDF Durapore-GV Millipore filter.

In a typical photocatalytic experiment 10 mL of aqueous 4-CP (15ppm) containing the NiO based materials were added to a cylindrical pyrex cell, oxygenated and covered air tightly with a serum cap. Photolysis was performed at ambient temperature in the photolysis apparatus. The solutions were magnetically stirred throughout the experiment. Analysis of the photolysed solutions was performed after filtration with a 0.2 mm MILLEX PVDF Durapore-GV Millipore filter.

Adsorption and photodegrdataion tests for NiO based materials (fig. 5 and

6) show that the photocatalytic yield is similar with adsorbtion yield.

Photocatalytic tests for photodegradation on 4-CP were made using different experimental conditions: catalysts (NiO and NiO/SiO2), irradiation sources (UVA, UVC) and catalyst loading (200, 600 ppm). The results presented in Figs. 7-9 confirm that yield changes in the photocatalytic degradation of 4- chlorophenol is mainly due to adsorption process.

NiO/SiO2 presents slightly better photocatalytic efficiency than NiO for 4- chlororphenol photodegradation (fig.7).

3.2. Degradation of pollutants using activated NiO based materials

3.2.1 Activation of NiO based nanomaterials with NaOCl

NiO based nanomaterials activated with NaOCl [21-23] was obtained by mixing an aqueos solution of NiO nanomaterials with NaOCl 13%, under vigorous stirring for 30 minutes, washed with water, centrifuged at 15000 rpm for 10 minutes and dried in air atmosphere. NaOCl activation of NiO nanoparticles generated an increase in their photocatalytic efficiency from 25% up to 55% as shown in Fig. 10. When using NiO/SiO2 activated nanoparticles no signifficant changes were noticed on the photodegradation yield (Fig. 11).

3.2.2. NiO based materials activated with γ-rays

The dose rate for the irradiation of NiO based nanomaterials were determined with Fricke’s dosimeter and were found equal to 7.98 kGy (correspondig to a 24 h irradiation), respectively 15.96 kGy (48h). The photocatalytic efficiency of NiO nanoparticles irradiated with 7.98 kGy increase with 30% in comparison with the non-irradiated nanoparticles. The photocatalytic activity of gamma-irradiated NiO nanoparticles was found to vary as a function of the irradiated dose applied. The photocatalytic efficciency for NiO 15.96 kGy is lower than for NiO 7.98 kGy (Fig.12). In the case of NiO/SiO2 irradiated samples the photocatalytic efficiency improves slightly when using 15.96kGy and remains unchanged for 7.98 kGy (Fig. 13).

For comparison NiO commercial nanoparticles purchased from SigmaAldrich were tested (Fig. 14). The synthesized NiO nanoparticles presented a higher photocatalytic efficiency for 2,4-chlorophenols photodegration (25%) then the commercial nanoparticles (21 %).

  1. Conclusion

NiO based nanomaterials were used as photocatalysts for degradation of dyes and organics. For crystal violet photodegradation NiO proved to be more efficient than NiO/SiO2, photocatalitic efficiency obtained was 50% in 33 minutes in comparison with 20% in 21 minutes for NiO/SiO2 nanoparticles. The efficiency obtained for chlorophenols photocatalytic degradation was 25% when using NiO, respectively 45% for NiO/SiO2. Photocatalytic efficiency of synthesized nanomaterials improved when gamma activated and NaOCl activated nanomaterials were used as photocatalysts. NiO based materials proved to be more effiecient for photocatalytic degradation of dyes than organics and the results recommends further studies in order to improve their properties by combining them with other photocatalyst like TiO2 and ZnO.


The work has been funded by the Sectoral Operational Programme Human Resources Development 2007-2013 of the Romanian Ministry of Labour, Family and Social Protection through the Financial Agreement POSDRU/6/1.5/S/19. PhD student Alina-Florentina Comănescu is grateful to Dr. Anastasia Hiskia, Dr. Kyriakos Papadopoulos and Dr. Theodoros Triantis for technical support and encouragement in extending this work.


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Nanosilver Pesticides

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Nanosilver Pesticides

EPA addresses data gaps, prepares to register more products

Britt Erickson

IN THE WASH Studies show a large variation in the amount of silver that leaches from nanosilver textiles during washing.

Consumer products that contain nanoscale silver particles are increasingly showing up in the marketplace. Nanosilver, known for its antimicrobial properties, can be added to plastics—such as food containers, water bottles, countertops, shower curtains, and floor coverings—as well as to textiles and building materials—such as paints, caulks, and adhesives.

The job of figuring out how to best regulate this growing class of nanotech products falls on the Environmental Protection Agency. The agency has jurisdiction because antimicrobials are considered pesticides and therefore fall under the Federal Insecticide, Fungicide & Rodenticide Act (FIFRA).

The problem facing the agency is how to get a handle on the ever-changing science behind these emerging nanosilver products. This understanding is essential for EPA to determine what data it needs to assess potential environmental, health, and safety risks and the best way to get those data. Under FIFRA, the agency has broad authority to require manufacturers to provide whatever data it deems necessary.

On one side, industry asserts to EPA that little or no leaching of nanosilver will occur from nanosilver products, and therefore exposure to humans and the environment will be minimal. When leaching does occur, they say, it is in the form of silver ions, which have been used in pesticide products for decades with no unintended effects.

Countering this stance are numerous consumer, health, and environmental groups that emphasize that nanosilver products have novel properties that can pose different risks to humans and the environment than non-nanoscale forms of silver. Such groups are urging EPA to require the full gamut of toxicity data for all nanosilver products under its jurisdiction.

To help inform how to assess risks associated with nanosilver pesticide products, EPA held a four-day meeting of its FIFRA Scientific Advisory Panel earlier this month. The external group of scientists pondered over whether EPA should allow data for non-nanoscale forms of silver (particles that measure greater than approximately 100 nm in any dimension) to fill in for nanosilver data (particles that measure approximately 1–100 nm in any dimension), and whether data for one nanosilver product can substitute for data for another nanosilver product.

Several companies have approached EPA trying to register pesticide products that contain nanosilver, William L. Jordan, senior policy adviser to the director of EPA’s Office of Pesticide Programs (OPP), told the advisory panel. And at least two nanosilver products have already been registered, he pointed out.

For those two products, EPA only has acute toxicity data to assess potential hazards. The data include acute oral toxicity, acute dermal toxicity, acute inhalation toxicity, eye irritation, dermal irritation, and skin sensitization, Jenny Tao, a toxicologist with OPP’s antimicrobials division, told the panel.

EPA is also reviewing applications submitted by four different companies seeking to register nanosilver products, and it expects to receive many more, on the basis of numerous inquiries from manufacturers in the U.S. and Asia, Dennis Edwards, a branch chief in OPP’s antimicrobials division, noted at the meeting.

According to Edwards, the four pending products are intended to be used as material preservatives. In such cases, nanosilver would be added to paint, plastic, or fabric to preserve the product by killing bacteria or other microbes that might spoil or contaminate it.

The use patterns for the four products are very similar to those of registered conventional silver products, Edwards noted. “The antimicrobial activity for all four products is attributed to the release of silver ions.”

About 110 antimicrobials that contain non-nanoscale silver are currently registered by EPA, according to Edwards. Silver has been used as an antimicrobial agent for hundreds of years, and there are a lot of data in the literature on it, he stressed.

“We are going to need new guidelines for nanoparticle characterization.”

EPA agrees with the manufacturers that if there is exposure to silver ions from nanosilver products, then the hazards will be the same as those for pesticides that contain elemental silver, Jordan said. “But the question that keeps coming up for us is whether we have an adequate basis for assessing the potential exposure to the nanosilver particles themselves.”

It is unclear whether nanosilver particles or silver ions are coming off the treated substrates in available leaching studies, Jordan noted. A recent study found that when silver is released from nanosilver textiles during washing, most of it is in the form of coarse (&gt;450 nm in diameter) particles (C&EN, Oct. 5, page 12). The particles have yet to be fully characterized.

EPA is considering three broad approaches to regulate nanosilver pesticide products, Jordan told the advisory panel. The first is to evaluate industry’s claim that there is limited exposure potential. In that case, EPA would only need to ask for data to confirm that there is minimal or no leaching of nanosilver. The agency would rely on the available toxicity data for elemental and ionic silver.

The second approach would focus on metabolism studies to determine whether nanoparticles and ionic silver behave the same way in various organisms. If they do, then EPA would assume that the data it has for elemental silver are sufficient to evaluate the risks associated with exposure to nanosilver products. If they behave differently, then the agency would shift to the third approach and ask for more data.

In the third approach, EPA would assume that nanosilver particles are significantly different from conventional silver. Nanosilver particles would be treated as new active ingredients and therefore would need to be supported by a full set of toxicity data, including subchronic and chronic mammalian toxicity studies, environmental fate and ecological effects studies, and a full complement of exposure studies.

No matter which approach or combination of approaches EPA decides to use, “we are going to need new guidelines for nanoparticle characterization,” Jordan noted. Several EPA scientists echoed that statement during the meeting, emphasizing that without sufficient characterization of nanomaterials, it is difficult to reproduce results or compare results of one toxicity study with another.

During a presentation on hazard assessment of nanosilver, Jessica P. Ryman-Rasmussen, a toxicologist in OPP’s health effects division, noted that the toxicology profiles for silver ions and nanosilver look very similar, “the similarity being that they are not really all that toxic.” However, EPA doesn’t have characterization data for the nanosilver-containing compounds, she said. “We don’t really know what the animals got dosed with, how dispersed it was, or how agglomerated it was.”

For incoming pesticide products, EPA traditionally asks for physicochemical properties such as physical state, chemical composition, solubility, density, and cation-anion exchange capacity, noted A. Najm Shamim, a chemist in OPP’s antimicrobials division.

But for nanosilver and other nanometal products, the agency is considering asking for additional properties, including size and size distribution of nanoparticles, surface area, surface reactivity, zeta potential, surface charge, catalytic properties, and aggregation processes, he noted.

The problem is that EPA does not have test guidelines or standardized methods for most of those characteristics, Shamim acknowledged. In addition, there are no standards against which manufacturers can normalize or validate their tests. “Every manufacturer has a different product,” he said.

Nanosilver products are made by many different processes, raising concerns for EPA about extrapolating toxicity data from one product to another. As an example, Shamim described two common manufacturing processes.

In one process, nanosized silver is incorporated into polymeric silica or attached to silica that is bonded with sulfur, forming a nanocomposite. The other process involves the addition of capping or dispersing agents—such as citric acid or its sodium salt—or polyvinyl pyrrolidone. These capping or dispersing agents keep the nanosilver dispersed in colloidal form and prevent aggregation, Shamim explained. “Nanoscale colloidal dispersions could be incorporated into polymeric materials like plastics or surface-coated on textile materials like socks.”

In comments presented at the meeting, Jaydee Hanson, policy director of the nonprofit International Center for Technology Assessment (ICTA), urged EPA to clarify which nanosilver products are pesticide products that must be approved and registered by the agency. In May 2008, ICTA filed a petition with EPA on behalf of a coalition of consumer, health, and environmental advocacy groups, pointing out nearly 300 self-identified nanosilver products already on the market. The petition called on EPA to exercise its authority under FIFRA and require that such products be registered by the agency. It also recommended that EPA require all relevant data from nanosilver manufacturers to better assess the risks of nanosilver products.

Murray J. Height, chief technology officer of Switzerland-based HeiQ Materials, a manufacturer of nanosilver textiles, presented a much different perspective. He provided information to the panel on behalf of the Silver Nanotechnology Working Group, an industry effort to promote the benefits of nanosilver products.

Height argued that nanosilver is not a new material, but rather the same material as colloidal silver, which has been used for centuries. He asserted that EPA doesn’t need more toxicity data on nanosilver products because those data already exist from products that have been on the market for decades. Height pointed to nanosilver biocides for killing algae in swimming pools and nanosilver-based carbon water filters.

Although most of the meeting was dedicated to nanosilver, EPA’s Jordan did bring up concerns about other nanoscale metals, including copper, in consumer products. Jordan’s remarks were spurred by comments submitted by the Natural Resources Defense Council. The environmental group recommended that the advisory panel consider nanoscale copper-based biocides for wood treatment. NRDC claimed that the product is in widespread use and that EPA has insufficient safety data on it.

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