Wildfires are either managed for resource benefit (wanted) or suppressed (unwanted).

• Wildfires that are managed for resource benefit are fires that achieve management objectives such as reducing wildfire risk, preparing sites for replanting, thinning, recycling nutrients, reducing pathogens, and improving forage. They may be allowed to burn if adequate resources are available. Usually, lightning naturally ignites this type of wildfire.

• Wildfires that are suppressed are fires that do not meet management objectives. They are typically suppressed by fire management agencies. These wildfires are often due to negligent human behavior such as smoking in forested areas or improperly extinguishing campfires. They may also be caused by intentional behavior by arsonists. The Federal Emergency Management Agency (FEMA) reports that more than four out of every five forest fires—representing nearly half of the acres burned each year—are started by people.

Management-ignited fires on wildlands are called prescribed fires. Similar to beneficial wildfires, prescribed fires are conducted to meet forest and rangeland management objectives.

In Idaho, land managers who conduct a "major" amount of prescribed burning participate in a bi-state smoke management program with Montana. The program is managed by the Montana/Idaho State Airshed Group, which was formed to limit the impacts of smoke generated from necessary forest and rangeland burning.

The Idaho Department of Lands (IDL) requires a permit for all open fires on any forest or rangeland during the closed fire season, which is generally May 10 through October 20. This requirement may be year-round in some areas. More stringent local ordinances also may apply, so contact your local fire department or district for more information. The Idaho Forest Practices Act, enforced by IDL, requires slash created by forest harvesting practices on state and private lands to be treated. The most common treatment technique involves burning the slash during periods of low fire danger. Check with IDL for further information about fire management activities.

Outdoor burning is by Sections 600-617 of the Rules for the Control of Air Pollution in Idaho (pdf on Department of Administration Web site), which are designed to protect human health and the environment by limiting emissions and minimizing the health impacts of open burning. These rules cover most kinds of outdoor fires including residential, recreational and warming, weed control, orchard, training, prescribed, and others.

Under Sections 550-562 of the Rules for the Control of Air Pollution in Idaho (pdf on Department of Administration Web site), known as the Air Pollution Emergency Rule , DEQ may issue health advisories and burn restrictions based on weather and air quality conditions. Notices are generally issued in the morning, but may be issued other times as needed. Notices are announced through the media (Internet, radio, television, newspapers).

Link to Air Pollution Emergency Rule: What Is It, What Does It Do?
(DEQ Publication: December 2004: pdf 60 kb, 2 pages)

Local ordinances may further restrict or prohibit open burning. Contact the nearest DEQ Regional Office for regulations applicable to your area. Always check with your local fire protection service to find out if burn restrictions are in effect or permits are required due to fire danger. Note that burn permits are issued by local authorities, not DEQ. If you live within the exterior boundaries of an Indian reservation, check with the tribal air quality or fire protection offices.

Click here for more information on burn bans on DEQ's Web site.

It is illegal to burn garbage and most human-made substances, including plastics, hazardous wastes, paints or painted materials, tires, and trade wastes (produced by a business), which emit hazardous pollutants into the air when they are burned. Specifically, the Rules for the Control of Air Pollution in Idaho (pdf on Department of Administration Web site) prohibit burning the following substances (certain exemptions may apply):

• Garbage (Garbage is defined in the Rules for the Control of Air Pollution in Idaho as "any waste consisting of putrescible animal and vegetable materials resulting from the handling, preparation, cooking and consumption of food including, but not limited to, wastes materials from households, markets, storage facilities, handling and sale of produce and other food products.")

• Dead animals, animal parts, or animal feces
• Motor vehicle parts or any materials resulting from a salvage operation
• Tires or other rubber materials or products
• Plastics
• Asphalt or composition roofing or any other asphaltic material or product
• Tar, tar paper, waste or heavy petroleum products, or paints
• Lumber or timbers treated with preservatives
• Trade (business-generated) waste
• Insulated wire
• Pathogenic wastes
• Hazardous wastes (Hazardous waste is defined in the Rules for the Control of Air Pollution in Idaho as "any waste or combination of wastes of a solid, liquid, semisolid, or contained gaseous form which, because of its quantity, concentration or characteristics (physical, chemical or biological) may: (a) Cause or significantly contribute to an increase in deaths or an increase in serious, irreversible or incapacitating reversible illnesses; or (b) Pose a substantial threat to human health or to the environment if improperly treated, stored, disposed of, or managed.")

As a result of a January 2007 court ruling, burning of crop residue on fields where crops are grown is no longer considered an allowable form of open burning on lands in the state outside of Indian reservations.

Smoke generated by wildland fires can pose a major health risk. It is primarily made up of small particles, gases, and water vapor, with trace amounts of hazardous air pollutants. Most harmful are the particles (or particulate matter) smaller than 2.5 micrometers in diameter (70 micrometers is the diameter of a human hair). If these particles are inhaled deeply into the lungs, they can damage lung tissue and cause respiratory and cardiovascular problems.

Symptoms from short-term smoke exposure range from scratchy throat, cough, irritated sinuses, headaches, runny nose, and stinging eyes to more serious reactions among persons with asthma, emphysema, congestive heart disease, and other existing medical conditions. Older adults and children are also high-risk groups. Find out what you can do to protect your health when smoke levels are dangerously high.

DEQ monitors air pollution in population centers throughout the state to ensure that air quality standards are being met. When real-time data are available, knowing the air quality for the day and how it will affect our health is a relatively easy matter. Monitoring smoke levels from wildland fires is difficult, however, because these fires usually occur in remote areas and the smoke impacts are transitory. Because wildland fire smoke is highly visible, it is possible to visually estimate smoke levels and estimate potential health impacts. Generally, the worse the visibility, the worse the smoke.

Use the table below to evaluate air quality conditions, identify potential health effects, and determine appropriate exertion levels based on the visibility range. Do not use this table when relative humidity is above 65%. Make a visual observation as follows:

1. Face away from the sun.
2. Determine the limit of your visibility range by looking for targets at known distances (miles). Visibility range is the point at which even high contrast objects totally disappear.
3. Use the visibility range values below to determine the applicable health category.

* Sensitive people include those with heart or lung disease, older adults, and children.

Acknowledgement: Visibility ranges adapted from data compiled by the Montana Department of Environmental Quality and U.S. Forest Service. Health categories and effects established by U.S. EPA.

 On DEQ's Web Site:

 Health-Related Documents

Wildfire Smoke and Your Health
(DEQ Fact Sheet, July 2003: pdf 22 kb, 2 pages)
Frequently asked questions and answers about the health effects of smoke and wildfires.

 On Other Web Sites:

 Federal Policies

EPA's Wildland and Prescribed Fire Policy (pdf)

 Wildfire Potential

National by Geographic Region

 Fire Information

National Interagency Fire Center

National fire news, including current statistics and state-by-state summaries.

 Weather and Climate Links

National Weather Service

 Online Smoke Forecasting by Region

 Satellite Links

 Webcams

 Surrounding States/Provinces Smoke Management and Real-Time Air Quality

Canada: smoke management | air quality