Air Quality Board

Ada County Emission Testing

Emission Testing

Vehicles are one of the largest contributors to harmful air pollution that leads to adverse health effects. A vehicle inspection program is a proven, cost-effective way to reduce air pollution and maintain good air quality. Ada County Air Quality Board was created in 1984. Every year, Department of Environmental Quality reviews the effectiveness of emission testing programs by looking at the annual testing results and using the latest emissions modeling. The emission reductions are compared to the initial modeling reductions that were estimated in 2008 when Idaho Code §39-116B was enacted. Each year, the program has seen a reduction in ozone precursors (volatile organic compounds and nitrogen oxides). With each annual review demonstrating greater emission reductions than estimated in 2008, the vehicle inspection program continues to be an effective control measure to minimizing harmful pollutants.


Air Quality

Maintaining Idaho’s air quality is a job where everyone can play a role. Poor air quality is unhealthy for everyone, but especially for children, senior citizens and people with respiratory conditions like asthma. With cleaner air, there are fewer trips to the emergency room and lower respiratory illness rates. It also keeps wildlife and plant life thriving.

Cleaner, healthier air requires both local and regional efforts. The Air Quality Board (AQB) leads Idaho in caring for the state’s air quality by partnering with communities, business and industry, organizations and private citizens to provide the knowledge and tools necessary to create workable solutions to air quality issues.

Air Quality Index

After the amount of pollution is measured, it is compared to the federal standard. To make it easy to compare the various pollutants and determine the air quality, the US Environmental Protection Agency (EPA) developed the Air Quality Index (AQI), a guide for reporting daily air quality.

The AQI indicates how clean or polluted the air is in a particular area and identifies potential health impacts. The AQI focuses on health effects that can happen within a few hours or days after breathing polluted air. Department of Environmental Quality uses the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.

You can think of the AQI as a measuring stick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health danger. For example, an AQI value of 50 represents good air quality and little potential to affect public health, while an AQI value over 300 represents hazardous air quality with potentially serious health impacts.

An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA has set to protect public health. So, AQI values below 100 are considered healthful. When AQI values are above 100, air quality is considered to be unhealthy—at first for certain sensitive groups of people, then for everyone as AQI values get higher.

Based on the measurements, air quality is then categorized according to health risk ranging from good to hazardous, with four stages in between. Each stage is assigned a color. Because the AQI is a national index, the values and colors used to show local air quality and the associated level of health concern are the same everywhere in the United States.

To learn more about Air Quality, below are links to the Environmental Protection Agency web sites.