How-to Guide

Indoor Air Quality

INTRODUCTION

Why Indoor Air Quality Matters

For many decades, the study of air pollution was largely confined to the outdoor environment. This makes sense, right?

Generally speaking, problems linked with outdoor air have been much more obvious. When you try to picture large cities following the Industrial Revolution, what comes to mind? Yep, the ever-growing miasma of automobile exhaust, smokestack emissions, and smog. This problem eventually became impossible to ignore, and ultimately forced scientists and governments to take action.

Fortunately, particulate matter and other pollution have dramatically declined over the past 40 years in the US, due in large part to regulations implemented by the Clean Air Act of 1970 and its subsequent amendments. Deaths linked to air pollution fell by around 30% between 1990 and 2010.

Unfortunately, as the outdoor air in the United States and other Western nations has become cleaner, our exposure to indoor pollutants has increased at the same time. Why? There are a few likely contributors.

For one thing, houses and office buildings have become more tightly sealed and insulated, in order to reduce the need for heating and cooling. This was a well-conceived adaptation to energy shortages in the 1970s, and one from which all of us continue to benefit. But a hidden consequence of this effort at energy conservation was a reduction in ventilation rates - meaning that pollutants within buildings could linger longer than ever before.

Furthermore, we are introducing more and more potential contaminants into the indoor environment in the form of personal care products, housekeeping supplies, pesticides, furnishings, and other substances. Indeed, the US Environmental Protection Agency (EPA) has estimated that concentrations of certain recognized pollutants may be 2-5 times higher than typical outdoor concentrations.

Finally, our lifestyle patterns have made the safety of indoor air more relevant now than perhaps ever in our history as a species. Research suggests that Americans, on average, spend about 90% of their time indoors (probably even more than that now). And research is starting to uncover the insidious role that indoor air quality may play in human health. Just as one example, asthma incidence has risen dramatically in Western countries, and is presently regarded as the most common chronic disease in children living in urban areas. Allergens and irritants circulating in indoor air have been linked to both the development of asthma and asthma attacks. No surprise there. But some more serious long-term effects may be less discernible, and only become evident after chronic low-grade exposure. For example, some research suggests that long- term exposure to indoor air pollutants are linked to elevated blood pressure and greater cardiovascular risk. Exposure to volatile organic compounds that emanate common household products has also been shown to be associated with increased cancer risk.

Perhaps even more remarkably, some observational and experimental evidence suggests that indoor air quality may impact the brain. For instance, chess players participating in tournaments held in buildings with poorer air quality are substantially more likely to make meaningful errors. And it is likely that the effect of air pollution on cognitive performance probably has implications beyond playing board games.

When researchers had workers spend one week in a conventional office building, and then a week in a highly ventilated building low in pollutants, the workers' cognitive performance rose a full 100% higher. Another instructive example comes from Los Angeles area school districts. The installation of basic commercially available air filters resulted in major boosts in math and English test scores - comparable to the impact associated with cutting class sizes by a third! Could clean air make you and your family smarter, more productive, and healthier? Seems very possible.

The effect of indoor air quality is subtle, and doesn't always produce an acute and easily recognizable impact on health and performance. But make no mistake, it matters. This guide will show you how to test indoor air quality, and support the maintenance of better air quality in your indoor spaces.

Causes of Indoor Air Pollution

Why have indoor air pollutants increased?

• Energy efficient construction
• Synthetic building materials
• Personal care items
• Pesticides
• Cleaners
• Cooking
• Security Issues
• Air fresheners

How do outdoor pollutants get inside buildings?

• Ventilation systems
• Cracks
• Open windows/doors
• People flow
• Moisture intrusion/mold

Types of Indoor Air Pollution and Some Effects

• Radon - Radon is a radioactive gas that is formed in soil. It can get into indoor environments through cracks and openings in floors and walls that are in contact with the earth. It is the leading cause of lung cancer in non-smokers, and the second leading cause of lung cancer overall. You cannot see or smell radon. You can only determine your exposure through testing, and every home should be tested, especially if you are in a high risk area. Here is a link to local radon zones from the Environmental Production Agency to identify parts of the US that are potentially subjected to indoor radon levels. More on radon testing kits below under Products.

• Secondhand and Thirdhand Smoke - Secondhand smoke refers to smoke exposure from other individuals' tobacco products, and thirdhand smoke refers to the residual contamination that results from indoor smoking. It has been linked to cancer and respiratory illness. Children are particularly susceptible to the effects of this form of pollution - it has been linked to asthma, ear infections, and SIDS (sudden infant death syndrome). Prevention is simple, albeit not easy. Needless to say, if you (or someone in your household) smokes, now is as good a time as any to quit. If that isn't an option, at least ensure that the behavior is strictly confined to the outdoors.

• Combustion Pollutants - Combustion pollutants are gases or particles that emanate from burning materials. In houses, the primary sources of such pollutants include space heaters, wood and gas stoves, water heaters, fireplaces, and dryers. Whether these pollutants are generated from these devices depends on the type of fuel used, as well as how well the appliance has been maintained and vented. The main combustion pollutants to be concerned about here are carbon monoxide (CO) and nitrogen dioxide (NO2). CO is colorless and odorless and interferes with delivery of oxygen in the body (obviously no bueno). Carbon monoxide can induce a range of health effects, including headaches, dizziness, nausea, and death (if exposed long enough.Can release carbon dioxide and nitrogen dioxide. These gases cause headaches, dizziness, weakness, nausea, and death - as well as eye, nose, throat irritation and respiratory infections. Nitrogen dioxide (NO2) is a colorless gas that causes shortness of breath and respiratory symptoms. It has a nasty, acrid smell, so you're less likely to miss it.

• Volatile Organic Compounds (VOCs) - Volatile organic compounds (VOCs) are organic chemicals that have a low boiling point. This property causes large numbers of molecules to sublimate or evaporate from the liquid or solid form of the compound, and be emitted into the air. Common examples that we may encounter on a daily basis include benzene, formaldehyde, tetrachloroethylene, ethylene glycol, toluene, xylene, and methylene chloride. Where exactly do they come from? They are emitted from a wide range of products in the home and office that contain organic solvents. If you look under your kitchen sink or in your bathroom right now, you will find some of them. They include:

These products can release organic compounds while they are being used, and they remain in the air for some time thereafter. They may also emit them while being stored. Levels of VOCs have been found to be 2-5 fold higher indoors than outdoors. Indeed, household goods have been shown to emit nearly as many VOCs as do automobiles in cities now.

VOCs cause headaches, nausea, and irritation in the eyes, nose, and throat. More severe exposure may result in damage to the liver, kidneys, and central nervous system. Some have been linked to cancer. You can limit your exposure to VOCs through proper ventilation and judicious storage of products that emit organic compounds.

• Mold - Molds are a ubiquitous form of fungi, often associated with moist surfaces. They produce spores that can float in the air, land on surfaces, and grow. They have been shown to trigger asthma attacks, as well as general hay fever symptoms like runny nose, red eyes, sneezing, and rashes. The best way to control mold is to limit moisture and humidity, improve ventilation, and clean frequently.

SOLUTIONS

• Clean - Reduce and prevent the accumulation of mold, animal dander, and dust.
• Ventilate - Create air flow between your indoor spaces and the outdoors around you.
• Purify - Add mechanical air filters and purifiers

Clean

Arguably the most effective way to improve indoor air is to eliminate the sources of pollution. This is also the least fun method, since it often involves something few of us enjoy: housework.

• Vacuum. Most experts recommend vacuuming floors at least once weekly. Look for a vacuum that uses a HEPA filter to trap extremely small particles and prevent them from recirculating into the air.

• Keep it tidy. Clutter can become a magnet for dust and other particles, and it can make it harder for you to effectively clean surfaces.

• Buy safer household products. Many indoor pollutants emanate from the products that we use in our homes (ironically, many of which are associated with cleaning). And labels like "green" or "natural" don't mean that they are better for you. Fortunately, the EPA has created a voluntary program called Safer Choice to help consumers find safe and effective products. Products that carry this label can only contain ingredients that have been evaluated by EPA scientists, and must meet requirements for chemical ingredient safety, performance, sustainability, surveillance, and VOC emissions. See below for some good examples, or refer to the database vourself.

• Clean your house using old-school methods. If you can't find safe products in stores, you might be able to get by with some basics sitting in your pantry. Plain old soap and water can often be used instead of detergents, bleach, ammonia, and other harsh cleaning agents. Vinegar and lemon juice is a time-tested method for cleaning dishes and other surfaces. And baking soda is a great scrubbing agent, which can also help reduce odors.

• Store hazardous chemicals somewhere else. Products that are known to emit pollutants should be kept somewhere where you spend less of your time if possible, like in a garage or shed, to reduce your exposure.

Ventilate

Another way to control pollution within the home is to increase circulation of fresh air from the outside. The benefit of doing so obviously depends upon the quality of your outdoor air. You should always do this when you are involved in an activity that increases concentrations of indoor pollutants inside, like painting or cleaning with chemicals that emit VOCs. This will also help rein in humidity levels inside your home.

• Open windows and doors. Opening your home to the outdoors, as a general rule, should reduce indoor pollutants. The plausibility of this option obviously depends on the weather, and how willing you are to potentially open your house to outdoor creatures.

• Run an air conditioner with the vent control open. This increases flow of air from the outside, and can be done with either window or central air conditioning units.

• Use fans. Window fans can help facilitate ventilation when you have the windows open but there isn't much of a breeze. And even ceiling fans and floor fans can improve air flow, which is a big plus. Bathroom and kitchen fans that exhaust to the outside are great for expelling pollutants in the parts of the house that are most prone to emitting them.

• Don't forget to change filters on a regular basis. Make sure to clean or swap out filters on central heating and air conditioning units so they can continue to work properly.

• Control humidity. Moisture in buildings and furnishings promotes the growth of mold, as well as dust mites and other undesired house guests. It may also enhance chemical emissions from household products The EPA recommends keeping indoor relative humidity below 60%, and ideally between 30-50%. Controlling humidity can be as simple as plugging leaks, and keeping your home ventilated, but it may also demand more significant alterations to your home or to your HVAC - please refer to this resource for more information.

Purify

When shopping for an air cleaner, the first consideration is what type of pollutant you wish to eliminate (particulate matter or gases). Then, when you are selecting a cleaner, you need to determine the size of the space you are trying to purify. Research testing air purifying devices has suggested that you need to choose a device that can cover somewhat more than the square footage of the room.

Particulate matter

Air purifiers that capture particles from the air fall into two main categories.

• Mechanical air filters - Mechanical air filters remove particulate matter by trapping them onto filter materials. High efficiency particulate air (HEPA) filters are a form of mechanical filter.

• Filters are graded through a system called the minimum efficiency reporting value (MERV rating), on a scale from 1-20. The higher the rating, the greater the amount of air particulates that the air filter can filter.

• Electronic air cleaners - Electronic air cleaners use electrostatic attraction to capture charged particles. They function on a principle kind of like magnets. As particles pass through the filters of the device, they obtain an electrical charge. Then, these charged particles get pulled toward a series of flat plates within the device, known as a collector, which is oppositely charged and thus is able to attract the particles.

Importantly, some electronic air cleaners emit ozone - in other words, they may actually create pollution themselves! Look for a cleaner that does not generate this lung irritant.

Gaseous pollutants

• Gas-phase air filters - Gas-phase air filters extract gases through a sorbent, a material that absorbs the gases. Activated carbon is a commonly used sorbent for this purpose. These types of filters are typically limited to removal of specific pollutants for which they were designed, and they need to be replaced frequently. Carbon filters are often situated in front of HEPA filters.

Pollutant destroyers

Another category of air cleaners relies upon ultraviolet light or ozone generation to destroy pollutants, rather than remove them from the environment. All of these may produce small amounts of ozone, which can be harmful to health.

• Ultraviolet germicidal irradiation (UVGI) cleaners - UVGI cleaners use radiation from lamps to eliminate biological pollutants (like viruses, bacteria, molds, and allergens). It is often used for disinfecting tools or surfaces that may be contaminated. Skin or eye exposure to germicidal wavelengths of radiation is unsafe.

• Photocatalytic oxidation (PCO) cleaners - PCO cleaners combine a UV lamp with a catalyst (often titanium dioxide) that reacts with the light. This elicits a chemical reaction that breaks the bonds of the molecules making up pollutants, and turning them into harmless products. They only work on certain gaseous pollutants and cannot address particulate matter.

• Ozone generators - These devices either use UV light or electrical discharges to produce ozone. Such air purifiers are neither safe nor particularly effective. No bueno. Consumers should look for purifiers that do not produce ozone, either intentionally or as a by-product of electrostatic attraction.

See below for information on how to test your indoor air quality, what to look for in a purifier, and a list of highly ranked purifiers with their specific features.

What about using plants for air purification?

You’ve probably heard before that indoor potted plants can clean the air inside your home. It’s an enticing idea, so it’s not surprising that it has taken off on Instagram and on gardening websites. Unfortunately, it seems pretty unlikely that this really works - or at least not in a way that is likely to meaningfully translate to us and the buildings we typically occupy.

Why did we come to believe this in the first place? It emerged from a series of experiments performed by NASA in the late 1980s and early 1990s. Scientists were trying to find a way to clean the air on space stations. These tightly sealed structures were prone to accumulating volatile organic compounds (VOCs), with no means to safely remove them. Through some clever testing, they discovered that certain species of plants were indeed able to remove chemicals from the air. Pretty cool, huh?

But there was a big problem with these experiments. They were performed in very small (often just a cubic meter) hermetically sealed chambers. A potted plant would be placed in this container, and a single VOC would be injected into the chamber. Then the researchers would monitor its subsequent decay, and compared that to the decay rate when it was placed in an empty vessel, to determine how much the plant was extracting from the air.

This study design makes good sense for modeling what might happen in a space station. But the buildings in which we spend most of our time are much bigger, and not nearly as tightly closed. In fact, the air within an office or a house is exchanging with the outdoor air all the time, which dilutes concentrations of VOCs way faster than a houseplant could. Plants, generally speaking, can’t compete with this natural ventilation. Normal indoor environments are dynamic - people and animals are constantly moving in and out, doors and windows open and close, and air is generally circulating and swapping with the outdoors.

So, how big of a difference does this make? Well, some environmental engineers looked at those past studies on phytoremediation, and determined that the rate at which plants could extract VOCs in a chamber was orders of magnitude slower than the rate of air exchange between a building and the outside environment. They calculated it would take 100-1000 houseplants per square meter to reach the same rate of VOC removal as normal air exchange. That’s a whole lot of plants! This is probably why later field studies that attempted to validate the test chamber results did not demonstrate success.

Alas, sometimes what happens in the lab doesn’t quite translate to real life. However, just because your peace lily or orchid might not be able to gobble up formaldehyde from the air doesn’t necessarily mean that plants aren’t a good thing to include in your daily life. Research has shown that people who sit in rooms filled with plants are happier, and interacting with indoor plants can reduce physiological stress and even lower blood pressure. And there is a growing body of evidence suggesting that spending time in green spaces is good for mental and physical health, so it makes sense to bring a little bit of nature into your living room to counterbalance our increasingly unnatural lifestyles. And hey, if they remove some VOCs in the process, that’s a bonus!

Plants

Phytoremediation does not appear to be a particularly efficient way to clean air. However, if you are of the philosophy that every little bit counts - and if you plan on getting plants anyway - here is a list of easy-to-find plants that were shown, in carefully controlled laboratory conditions, to be able to extract volatile organic compounds.

OUTDOOR AIR QUALITY

Outdoor Air Quality Overview

• WHO estimates that ambient air pollution accounts for 4.2 million deaths per year due to stroke, heart disease, lung cancer, and respiratory diseases.

• The American Lung Association estimates that more than 40% of Americans—over 135 million people—are living in places with unhealthy levels of ozone or particle pollution.

• People at particular risk include:
• Children
• Older adults
• Current or former smokers
• People with underlying conditions:
• Asthma
• Cardiovascular disease
• Chronic obstructive pulmonary disease (COPD)
• Lung cancer

How to assess your exposure to outdoor air pollution (US)

• Air Quality Index (AQI)
• Air pollution levels are measured daily in counties all over the US
• Measures five major air pollutants
• Ground level ozone
• Carbon monoxide
• Sulfur dioxide
• Nitrogen dioxide
• Airborne particles
• Ranked on a scale from 0 up to 500
• Under 50 means air quality is good
• Higher AQI = higher air pollution levels
• The AQI further breaks air pollution levels into color-coded categories

How to minimize impact of outdoor air pollution on your health when the AQI is orange or worse

• Stay inside as much as possible
• Keep doors and windows closed
• Use a HEPA air filter inside, especially in rooms where you spend a lot of time or sleep
• Rating of H13 or higher
• Avoid exercise or prolonged exertion outdoors
• Health effects of air pollution are exacerbated by deep breathing
• Go to a gym or work out at home.
• Always avoid exercising near traffic.
• Vehicles on busy highways generate emissions around them, even on days when local air pollution levels are overall low.
• Wear a mask if you must be outside for long periods of time
• Evidence for masks for protection against air pollution is limited
• Ideally, masks should be made of materials that can filter tiny particles and should form a tight seal around the nose and mouth
• Mask types in order of effectiveness
• Best have a rating of N95 or higher (filters out at least 95% of particles that are 2.5 microns in width*)
• Other equivalent standards are KN95 and FFP2
• If N95 isn’t an option, a surgical mask may also help filter fine particles and protect against the acute cardiovascular effects of air pollution to a lesser degree
• Cloth masks and bandanas are much less effective; use as last resort
• Visit a health care provider if you believe you are experiencing adverse effects from pollution
• Source: WHO guidance
• *PM2.5 - 2.5 microns in width and almost 30 times smaller than the diameter of a human hair. Particles smaller than 2.5 micrometers are considered more harmful than larger particles because they can penetrate the lungs more deeply.

Things you can personally do to reduce your contribution to outdoor air pollution

• Use less energy at home.
• Get an energy audit.
• Switch to efficient appliances and heating systems.
• Drive less.
• Vehicle exhaust is a major source of air pollution.
• Possible options:
• Bike
• Public transportation
• Carpool.
• Work remotely.
• Switch to a hybrid or electric vehicle.
• Keep your car in good repair.
• Fix exhaust and oxygen sensor problems.
• Check tire pressure monthly.
• (Smart thing to do anyway, right?)
• Turn off your engine when possible (like at drive-thrus).
• Idling for more than 10 seconds uses more fuel and produces more emissions than stopping and restarting your engine does.
• Idling Reduction for Personal Vehicles
• Switch to electric or hand-powered lawn equipment.
• Gas-powered lawn mowers and leaf/snow blowers can generate more pollution than you would think. One study in Sweden found that the air pollution from cutting grass for an hour with a gasoline-powered lawn mower is about the same as that from a 100-mile automobile ride.
• Don't burn garbage or wood.
• Plant trees.
• Trees remove pollutants from the air
• Trees lower the temperature of the surrounding area (especially urban areas)
• Emission of many pollutants are temperature-dependent
• Reduces ozone formation

REFERENCES

Papers

• Air Filters, Pollution and Student Achievement
• Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments
• The Impact of Indoor Climate on Human Cognition: Evidence from Chess Tournaments
• The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants
• The Total Exposure Assessment Methodology (Team) Study: Direct Measurement of Personal Exposures through Air and Water for 600 Residents of Several U.S. Cities
• Estimated Long-Term (1981-2016) Concentrations of Ambient Fine Particulate Matter across North America from Chemical Transport Modeling, Satellite Remote Sensing, and Ground-Based Measurements
• Long-term trends in the ambient PM2.5- and O3-related mortality burdens in the United States under emission reductions from 1990 to 2010
• Volatile chemical products emerging as largest petrochemical source of urban organic emissions
• Potted plants do not improve indoor air quality: a review and analysis of reported VOC removal efficiencies

Appendix A

Plant Photos

Calathea

Pilea

Ficus Tineke

Dragon Tree (Draceana Mariginata)

Peace Lilies - Eliminate formaldehyde, benzene, trichloroethylene, xylene, ammonia, and more. Keep soil slightly moist. Toxic to animals and humans.

Chinese Evergreen (Aglaonema) - Eliminates benzene, carbon monoxide, formaldehyde, trichloroethylene, and more. Water moderately and allow compost to almost dry out before watering. Toxic to animals.

Rubber Plant - Eliminates carbon monoxide, formaldehyde, trichloroethylene and more. Water moderately to keep the soil moist, especially in the winter. Toxic to animals.

English Ivy - Eliminates benzene, carbon monoxide, formaldehyde, trichloroethylene, and more. Water generously during growth, but don’t overwater during the winter. Toxic to animals and humans.

Bamboo Palm - Eliminates formaldehyde, benzene, carbon monoxide, xylene, chloroform, and more. Keep the soil moist and mist occasionally. Non-toxic.

Golden Pothos - Eliminates formaldehyde, xylene, toluene, benzene, carbon monoxide, and more. Water when the soil is dry. Toxic to animals. Use 4 plants per person.

Snake Plant - Converts CO2 to O2 at night. Requires 6 to 8 waist high plants per person for a bedroom.

Areca Palm - Eliminates benzene, carbon monoxide, formaldehyde, trichloroethylene, xylene, and removes CO2 and converts it to O2. Needs plenty of water during growth, but less in the winter. Non-toxic. Requires 4 shoulder height plants per person.

Dracaena Plant - Eliminates formaldehyde, xylene, toluene, benzene, trichloroethylene, and especially acetone. Keep the soil damp but not soggy. Toxic to animals.

Bromeliad - Excellent at scrubbing air of multiple chemicals.

Spider Plant - Eliminates formaldehyde, xylene. Water two to three times a week. Non-toxic.

Related resources

Products

Plant Delivery, Maintenance, and Education

• Léon & George

Testing the Air in Your Home

• Radon
• Radon test kit
• Find a discounted radon test kit or measurement and mitigation professional by the EPA
• Carbon monoxide
• Plug-in carbon monoxide detector
• Battery-operated carbon monoxide alarm
• Battery-operated carbon monoxide + smoke detector
• Mold
• Mold detection kit
• Digital moisture meter

Indoor Air Quality (IAQ) Monitoring

An IAQ monitor is an electronic device that continuously tests and reports the levels of pollution in your home. Devices vary, but usually test for particulate matter, chemical pollutants, and humidity. Some track temperature, carbon monoxide, carbon dioxide, and formaldehyde levels.

Here are just a few of the many IAQ testers you can research:

Note - Listed prices are what we discovered at the time of creating this document. These prices may change. Additionally, over time, manufacturers release new products so use this product list to get a sense of the types of products offered, and the range of prices for these products.

• Foobot - Price: $199. Measures: Particulate matter, chemical pollutants, humidity, temperature. Features: Dedicated app to track readings and compare them to outside air, smarthome enabled, offers general IAQ reading with single light
• Awair Glow - Price: $99. Measures: Chemicals (VOCs), temperature, humidity, Carbon Dioxide. Features: Dedicated app to track readings, can turn on smart and non-smart devices with its external power outlet, night light
• Netatmo - Price: $99.99. Measures: Humidity, air quality, noise, temperature. Features: Dedicated app to track readings, smarthome enabled, offers general IAQ reading with single light

Air Filters & Purifiers

Top Ranked Air Purifiers based on 8 different reviews from Home Air Quality Guide, Amazon Best Seller List, Forbes Magazine, Reviewed, Air Purifier Ratings, Buyers Guide, Best Reviews, and Consumer Voice.

• Alen BreathSmart - The Classic Large Room Air Purifier quietly cleans up to 1100 sq. ft. every 30 minutes. It has a HEP-Pure filter and a Laser Smart Sensor, which also detects airborne particles down to 0.3 microns. The Air Quality Indicator Light always reflects the real-time purity of the room’s air. Comes in 14 different colors and panels.
• Coverage: 1100 sq. ft.
• Cost: $585.
• BlueAir - The BlueAir HEPASilent 450E air purifier uses an electrostatic (air ioniser) technology and a HEPA type air filter. The base BlueAir air purifier does not have carbon so will not remove odor. Has a digital display and a filter replacement indicator, dust/gas sensor, and timer. There is an option to upgrade to the SmokeStop filters for gas removal and these filters are $119.95.
• Coverage: 365 sq. ft.
• Cost: $629
• Coway - Features a 4-stage Air Purification System (Pre-filter, True HEPA, Carbon Filter, and ionizer to eliminate the widest range of pollutants and odors). Its Eco Mode cuts off when it senses the air is clean. Two colors: black and white.
• Coverage: 360 sq. ft.
• Cost: $120
• Dyson Pure Cool Desk Purifier - Features a Dyson HEPA Filter with a layer of activated carbon granules to capture odors and fumes. Comes in tower-size and desktop-size. Desk-size is just 25 inches tall and fits into small spaces.
• Coverage: dependant on size of unit.
• Cost: $400.
• Germ Guardian - Uses a 3-in-1 Air Cleaning System: True HEPA Filter, Carbon Filter, and UV-C Light. Lightweight and moveable. Some plastic odor in the first 48 hours of use.
• Coverage: 193 sq. ft.
• Cost: $100-180 (depending on size and model).
• Honeywell - The #1 brand recommended by allergists. Uses a True HEPA Filter and Carbon Filter. Has an automatic shut off timer with 2, 4, and 8-hour intervals, easy tap control buttons and turbo fan mode. Replacement filters cost about $40 for a 3-pack.
• Coverage: 465 sq. ft.
• Cost: $249.
• Levoit Compact Air Purifier - Small size for home, work, or traveling. Uses 3-stage Air Filtration System: True HEPA, Activated Carbon, and Pre-Filter. Night light.
• Coverage: 86 sq. ft. (larger model available).
• Cost: $249.
• Molekule - Has excellent features. It removes indoor air pollutants and destroys them using both a Pre-filter and a Nano-Filter and catches pollutants 1000 times smaller than those the average air purifier can destroy. Sleek and elegant, this purifier is only available on the company’s website.
• Coverage: 465 sq. ft.
• Cost: $799
• Rabbitt Air MinusA2 - Features a Pre-filter, Medium Filter, BioGS HEPA Filter, Carbon Filter, Ion Generator, and Customized Filter which lets you prioritize functions. Can also customize color and design. Wall mountable.
• Coverage: 700 sq. ft.
• Cost: $549
• Winix 5500 - Uses a patented PlasmaWave technology which offers the same air cleaning advantages of an ionizer but doesn’t produce harmful side effects or ozone. Also uses a True HEPA Filter and a Carbon Filter. A Smart Sensor monitors air quality.
• Coverage: 360 sq. ft.
• Cost: Under $200.

This review was conducted in January, 2020. Product manufacturers release new models and also can change pricing so please see the manufacturer's website for the most up to date information and for their latest products.

Air Purifier Features

• Pre-Filter - prolongs life of main filter.
• True HEPA filter - highest standard filter - eliminates 99.97% of 0.3 micron particles.
• Energy Star - Models with this EPA-backed symbol are 40% more energy efficient. (If you’re running a purifier all the time, this is a valuable consideration.)
• Smart Enabled Features - Enables the purifier to be controlled by mobile devices using apps.
• Smart Sensors - Monitors air quality and tells the purifier to adjust itself.
• Light Sensor - Monitors light in the room and triggers the purifier to go into sleep mode when dark.

Other Products

• LeadCheck Swabs
• Airinum masks

EPA’s Safer Choice: Selected Cleaning Products

This list is not comprehensive - please refer to the database for other products.

• Multi-purpose cleaners and wipes (Fragrance free)
• Berkley Green All Purpose Cleaning Wipes (Free of Dyes & Perfumes) B3890SCWFC1
• Berkley Green Baby All Purpose Cleaning Wipes (Free of Dyes & Perfumes)
• Clorox Compostable Cleaning Wipes
• Seventh Generation All Purpose Natural Cleaner
• Walmart Parent's Choice Multi-Purpose Nursery Cleaner
• Rust-Oleum Cleaner & Degreaser Stain Remover
• Dish soap (fragrance free)
• Berkley Green Dish Soap Free of Dyes and Perfume B3765FC1
• Clorox Green Works Naturally-Derived Dishwashing Liquid
• ECOS Dishmate Dish Soap
• Seventh Generation Dishwashing Liquid
• Floor cleaners
• Berkley Green Wood Floor Cleaner Free & Clear (B3855FC1)
• ECOS PRO Neutral Floor Cleaner Concentrated 1:128
• Hand soap (fragrance free)
• Berkley Green Foaming Hand Soap Scent (B3272FC1)
• ECOS Hand Soap
• Seventh Generation Hand Wash
• Laundry detergent (fragrance free)
• Honest Laundry Detergent
• Berkley Green Premium Laundry No Dyes or Fragrances (B3814FC1)
• ECOS Free and Clear
• Seventh Generation Laundry Detergent
• Tub/tile cleaner
• Berkley Green Bathroom (Free of Dyes & Perfumes)
• Seventh Generation Tub & Tile Cleaner Emerald Cypress & Fir
• Toilet bowl cleaner
• Berkley Green Toilet Bowl Cleaner (B3595)
• Seventh Generation Toilet Bowl Cleaner Emerald Cypress & Fir
• Window/glass cleaners (fragrance free)
• Berkley Green Glass & Window (B3881FC1)
• Seventh Generation Glass & Surface Natural Cleaner
• Rust-Oleum Cleaner & Degreaser Stain Remover
• Other products
• ECOS Pet Shampoo
• Arm & Hammer Fruit and Vegetable Wash