What is AQI?
Aura Air’s Air Quality Index (AQI) was developed based on academic research, national AQIs, and other important considerations.
The AQI scale goes from 0 = ‘Excellent’ to 500 = ‘Hazardous’ with 6 colour-coded categories of equal lengths, as you can see here:
What sensors does the device measure?
Indoor AQI
CO
Carbon Monoxide (CO) is a poisonous gas that is produced from burning fuels such as wood, oil, natural gas, kerosene, coal, and gasoline. Because CO is invisible, odorless, tasteless, and non-irritating, the gas can cause harm before you are aware of its presence.
Average levels in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher.
CO2
Carbon dioxide (CO2) is the gas that people and plants exhale while breathing.
250 – 400 ppm: background (normal) outdoor air level.
400 – 1,000 ppm: typical level found in occupied spaces with good air exchange.
1,000 – 2,000 ppm: level associated with complaints of drowsiness and poor air.
2,000 – 5,000 ppm: level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate, and slight nausea may also be present.
5,000 ppm: this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.
40,000 ppm: this level is immediately harmful due to oxygen deprivation
VOCs
Total Volatile Organic Compounds are a large group of chemicals that are found in many products we use to build and maintain our homes. Once these chemicals are in our homes, they are released or “off-gassed” into the indoor air we breathe.
VOC concentration levels between 50 parts per billion (ppb) and 325 ppb are considered acceptable. Similarly, it is recommended that indoor air VOC concentrations not exceed 500 ppb.
PM 10
Particles in the PM10 size range are commonly present in the air and may be drawn into the body with every breath. In the lungs, particles can have a direct physical effect and/or be absorbed into the blood.
Technically, there isn’t a safe level of PM10, as any amount of particulate matter in your air isn’t a good thing. Although, the recommended normal level of PM10 should be 100 micrograms cubic meter
PM 2.5
Fine particulate matter (PM 2.5) is an air pollutant that is a concern for people’s health when levels in the air are high. PM2.5 are tiny particles in the air that reduce visibility and cause the air to appear hazy when levels are elevated.
The normal level of PM2.5 level should be 60 microgram cubic meter.
Indoor AQI Guide for PM2.5
0-50 is Good– No health impacts are expected when air quality is in this range.
51-100 is Moderate– Individuals who are unusually sensitive to NO2 should consider limiting prolonged outdoor exertion.
101-150 is Unhealthy for Sensitive Groups- Groups such as:
People with lung disease (Asthma, COPD, etc .) & Children and older adults, should limit prolonged outdoor exertion.
151-200 is Unhealthy– Groups such as:
People with lung disease (Asthma, COPD, etc.) & Children and older adults should AVOID prolonged outdoor exertion.
Everyone else should LIMIT prolonged outdoor exertion
201-300 is Very Unhealthy– Groups such as: People with lung disease (Asthma, COPD, etc.) & Children and older adults should AVOID ALL prolonged outdoor exertion.
Everyone else should LIMIT prolonged outdoor exertion
Outdoor AQI
The outdoor AQI (Air Quality Index) presented is based on EPA’s national air quality standards.
The AQI scale goes from 0 = ‘Excellent’ to 500 = ‘Hazardous’ with 6 colour-coded categories of equal lengths. AQI’s often vary between countries.
NO2
Nitrogen oxides are a group of seven gases and compounds composed of nitrogen and oxygen. Nitrogen oxides are emitted from vehicle exhaust, and the burning of coal, oil, diesel fuel, and natural gas, especially from electric power plants. They are also emitted by cigarettes, gas stoves, home heating appliances, and wood burning.
EPA (United States Environmental Protection Agency), set a 1-hour NO2 standard at the level of 100 parts per billion (ppb).
The annual average of standard NO2 of 53 ppb.
Outdoor AQI Guide for Nitrogen Dioxide (NO2)
0-50 is Good– No health impacts are expected when air quality is in this range.
51-100 is Moderate– Individuals who are unusually sensitive to NO2 should consider limiting prolonged outdoor exertion.
101-150 is Unhealthy for Sensitive Groups– Groups such as: People with lung disease (Asthma, COPD, etc .) & Children and older adults, should limit prolonged outdoor exertion.
151-200 is Unhealthy– Groups such as: People with lung disease (Asthma, COPD, etc.) & Children and older adults should AVOID prolonged outdoor exertion. Everyone else should LIMIT prolonged outdoor exertion
201-300 is Very Unhealthy– Groups such as: People with lung disease (Asthma, COPD, etc.) & Children and older adults should AVOID ALL prolonged outdoor exertion. Everyone else should LIMIT prolonged outdoor exertion
O3
Ozone is a gas that occurs both in the earth’s upper atmosphere and at the earth’s ground level. In the upper atmosphere, ozone protects life on earth from the sun’s harmful ultraviolet rays. Ozone on the ground level is the main ingredient of smog. It is formed when sunlight reacts with pollution from vehicles, power plants, and industrial sources. Ozone pollution is worse in the afternoon and early evening.
The ozone standard is set at a level of 0.075 ppm averaged over an 8-hour period.
ground-level ozone standard to 0.070 ppm, averaged over an 8-hour period. This standard is met at an air quality monitor when the 3-year average of the annual fourth-highest daily maximum 8-hour average ozone concentration is less than or equal to 0.070 ppm
SO2
Sulphur dioxide is an invisible gas that has an unpleasant, sharp smell. It reacts easily with other substances to form harmful compounds, such as sulfuric acid, sulfurous acid, and sulfate particles.
Sulphur Dioxide (SO2) is generally recognized between 0.3-1.4 ppm and is easily noticeable at 3 ppm
It can be detected by taste at concentrations of 0.35-1.05 ppm and has a strong and irritating smell. The odor threshold is between 0.67-4.75 ppm
