Air Purifier Glossary
So-called "pure" air is a mixture of gases containing about 78 percent nitrogen; 21 percent oxygen; less than 1 percent carbon dioxide, argon, and other gases and varying amounts of water vapor.
Amounts of foreign and/or natural substances occurring in the atmosphere that may result in adverse effects on humans, animals, vegetation, and/or materials.
Air Quality Index (AQI):
A numerical index used for reporting severity of air pollution levels to the public. the AQI incorporates five criteria pollutants - ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide - into a single index. AQI levels range from 0 (Good air quality) to 500 (Hazardous air quality).
Air Quality Standard (AQS):
The prescribed level of a pollutant in the outside air that should not be exceeded during a specific time period in order to protect public's health. Established by both federal and state governments.
A generic term referring to a harmful chemical or group of chemicals in the air. Substances that are especially harmful to health, Technically, any compound that is in the air and has the potential to produce adverse health effects is an air toxin.
A substance capable of causing an allergic reaction because of an individual's sensitivity to that substance.
Agents derived from, or that are, living organisms (e.g., viruses, bacteria, fungi, and mammal and bird antigens) that can be inhaled and can cause many types of health effects including allergic reactions, respiratory disorders, hypersensitivity diseases, and infectious diseases. Also referred to as "micro-biologicals" or "microbials."
Building-Related Illness (BRI):
Diagnosable illness whose symptoms can be identified and whose cause can be directly attributed to airborne building pollutants (e.g., Legionnaire’s disease, hypersensitivity pneumonitis). Contrast with "Sick Building Syndrome".
Activated carbon is a crude form of graphite with a random, imperfect structure which is highly porous over a broad range of pore sizes from visible cracks and crevices to molecular dimensions. The graphite structure gives the carbon its very large surface area which allows the carbon to adsorb a wide range of compounds. It has the strongest physical adsorption forces, or the highest volume of adsorbing porosity, of any material known to mankind. Activated carbon can have a surface of greater than 1000m²/g. This means 3g of activated carbon can have the surface area of a football field.
Clean Air Delivery Rate (CADR):
It is the fraction of particles (of a particular size distribution) that have been removed from the air, multiplied by the air flow rate (in CFM) through the device. Hence, you may have a different CADR smoke, pollen, and dust.
Cubic feet per minute (CFM):
The amount of air, in cubic feet, that flows through a given space in one minute. 1 CFM equals approximately 2 liters per second (1/s).
Air that has been heated, cooled, humidified, or dehumidified to maintain an interior space within the "comfort zone." (Sometimes referred to as "tempered" air.)
Environmental Illness (EI):
A term for diseases caused by the human-made environment we live in. Some diseases can have either natural or artificial causes.
Environmental Tobacco Smoke (ETS):
Mixture of smoke from the burning end of a cigarette, pipe, or cigar and smoke exhaled by the smoker also called secondhand smoke (SHS).
Any of a group of parasitic lower plants that lack chlorophyll, including molds and mildews
High Efficiency Particulate Air (HEPA):
HEPA filters capture variously sized particles within a multi-layered netting usually made out of very fine fiberglass threads (much thinner than the size of a human hair strand!) with varying sized gaps. The filter is airtight, and comprised of a dense sheet of small fibers pleated and sealed in a metal or plastic frame.
Compounds containing various combinations of hydrogen and carbon atoms. They may be emitted into the air by natural sources (e.g., trees) or as a result of fossil and vegetative fuel combustion, fuel volatilization, and solvent use. Hydrocarbons are a major contributor to smog.
Uses high voltage to give an electrical charge (usually negative) to either particles that move through the ionizer, or to molecules in the air.
Indoor air quality (IAQ):
The air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants.
A micron is one-millionth of a meter or one twenty-five thousandth of an inch.
Minimum Efficiency Reporting Value (MERV):
A report for the effectiveness of air filters where the values are a scale designed to represent the worst-case performance of a filter when dealing with particles in the range of 0.3 to 10 microns.
Multiple Chemical Sensitivity (MCS):
A condition wherein a person is sensitive or intolerant to a number of chemicals and other irritants at very low concentrations. (Distinct from "allergic")
Chemicals that contain carbon. Volatile Organic Compounds vaporize at room temperature and pressure. They are found in many common household products and building materials.
Parts per million (PPM):
The number of units of mass of a contaminant per million units of total mass.
Particulate Matter (PM):
Solid or liquid particles of soot, dust, smoke, fumes, and aerosols.
Particulate Matter less than 10 microns (PMIO):
Tiny solid or liquid particles of soot, dust, smoke, fumes, and aerosols. The size of the particles (10 microns or smaller) allows them to easily enter the air sacs in the lungs where they may be deposited and result in adverse health effects. PM10 also causes visibility reduction and is a criteria air pollutant.
Particulate Matter equal or less than 2.5 microns (PM2.5):
Ultra-fine particles, or PM2.5, pose an increased health risk over PM10 because PM2.5 can deposit deep in the lung and contain substances that are particularly harmful to human health. The United States Environmental Protection Agency promulgated national PM2.5 standards in 1997.
Photocatalytic Oxidation. Reaction when UV light strikes tubes coated with Titanium Dioxide that oxidizes airborne pollutants.
Radon (Rn) (and Radon Decay Products):
Radon is a radioactive gas formed in the decay of uranium. The radon decay products (also called radon daughters or progeny) can be breathed into the lung where they continue to release radiation as they further decay.
Reactive Organic Gas (ROG):
A photochemical reactive chemical gas composed of non-methane hydrocarbons that may contribute to the formation of smog. Also sometimes referred to as Non-Methane Organic Gases (NMOGs).
Sick Building Syndrome (SBS):
Term that refers to a set of symptoms that affect some number of building occupants during the time they spend in the building and diminish or go away when they leave the building.
A combination of smoke and other particulates including ozone, hydrocarbons, nitrogen oxides, and other chemically reactive compounds which, under certain conditions of weather and sunlight, may result in a murky brown haze that causes adverse health effects.
Very fine carbon particles that have a black appearance when emitted into the air.
Volatile Organic Compounds (VOCs):
Compounds that vaporize (become a gas) at room temperature. Common sources include housekeeping and maintenance products, and building and furnishing materials.