Air Pollution Control Program fact sheet
Division of Environmental Quality Director: Kyra Moore

Odors, dust, asbestos, open burning and freon have the potential to affect air quality in Missouri. This fact sheet includes information about each of these subjects, discusses its affects on air quality and outlines the best approach for dealing with those effects. Regardless of permit requirements, these guidelines must be followed and are enforceable by the Missouri Department of Natural Resources.

Emission of Odors

Odors are a byproduct of many factories and businesses. Odors can become a problem when they negatively affect air quality. If someone complains about an odor from a certain property, the odor will be investigated if the source is regulated. If the department determines the odor originated on the property and that it exceeds the regulatory limit, the facility may receive a violation. Facilities are required to correct the situation by controlling the odor. There are some exemptions to this rule, as well as additional regulations for large commercial farms. Review Animal Feeding Operation Permits and Regulations in Missouri - PUB2351 for classifications of large commercial farms. MoDNR team members follow odor assessment procedure MDNR-DEQ-001: Nasal Ranger Operation and Use when investigating odor concerns. Refer to Code of State Regulations, 10 CSR 10 for more about odor emission regulations, exceptions and location specific information.

Emission of Dust

Dust is a visible air pollutant whose sources include private gravel roads or construction projects. Dust can be a problem if it is visible on surfaces or in the air beyond the property line of the source that produces it. If the department determines that an activity on a piece of property is producing enough dust to leave the property, the facility on that property may be given a violation. If this happens, it is an indication that control measures need to be introduced. Some exceptions to this rule do apply. For more information on dust emissions, visit 10 CSR 10.


Asbestos is a naturally occurring mineral fiber that was widely used in many different products, especially building materials, until the 1970s. It is still manufactured in some products today. Asbestos can cause many health problems, including lung cancer. Before demolition or renovation activities begin in a regulated structure, a Missouri-certified asbestos inspector must conduct an inspection.

If asbestos is found, it will probably need to be removed by a Missouri-registered asbestos abatement contractor. All demolition projects must send notification to the department along with a copy of the inspection report at least 10 working days before demolition begins. This must be done even if no asbestos was found in the structure. More details about asbestos is available in the fact sheet Asbestos: What is it and why is it a concern? - PUB2077.

For exemptions, examples of asbestos-containing materials, asbestos inspection and removal requirements, review Asbestos Requirements for Demolition and Renovation Projects - PUB2157. A list of Missouri-certified asbestos inspectors and notification forms is available on the department's Asbestos webpage.

Open Burning

The burning of any material that allows particles, such as smoke and ash, to go directly into the air without going through a stack or chimney is called open burning. Open burning can produce toxic emissions that are harmful to health and the environment. The department allows open burning for some agricultural and land-clearing purposes, as well as for recreational and household purposes (some restrictions may apply). Certain cities and counties restrict open burning, so check with local authorities before burning. The open burning of any waste from businesses is usually not permitted, however, there may be some exceptions. Open burning permits may be required in some situations. For more information about open burning and location specific information, review Facts on Open Burning Under Missouri Regulations - PUB2047. If there is a question about whether open burning is allowed in a certain situation, call the Department of Natural Resources.

Freon Servicing

Freon is a generic term for refrigerants used in many air conditioners and major appliances. Older air conditioners and major appliances often use a type of chlorofluorocarbon (CFC) that damages the earth’s protective ozone layer. It has been replaced, in many cases, with various types of hydrochlorofluorocarbon (HCFC). Many HCFCs are also being phased out and will eventually have to be replaced. HCFCs, while not as harmful as CFCs, still damage the earth’s ozone layer.

It is very important that all CFCs be contained, whether in the servicing of an air conditioner or when throwing away an appliance that contains CFCs. All containers that hold CFCs should be clearly labeled. HCFCs cannot be used in equipment that use CFCs. CFCs are not considered hazardous waste unless they are mixed with other waste products. However, all freon should only be handled by trained and certified professionals. To find out more about how freon should be controlled, read Prohibition of Major Appliance Disposal in Landfills - PUB929.

Different Requirements May Exist

Some areas may have different requirements than the rest of the state for the pollutants in this fact sheet. Use the contact information provided below to check the regulations in your area.

Contact Information

For more information on the department’s asbestos requirements, you may contact the department’s Air Pollution Control Program or one of the department’s other offices. In Missouri, there are three local agencies that have an agreement with the department to enforce Missouri’s asbestos requirements as well as local ordinances. These local agencies are:

Kansas CityKansas City Health Department
Air Quality Program
St. Louis CountySt. Louis County Health Department314-615-8924
St. Louis (city)St. Louis Division of Air Pollution Control
Air Quality Program

One other local agency does not process asbestos notifications, but they perform compliance inspections of regulated abatement projects and demolitions, and may have additional local ordinances concerning asbestos that they enforce:

SpringfieldSpringfield-Greene County Health Department of Environmental Services417-864-1412

Before performing a project in one of these jurisdictions, you should contact the appropriate agency to determine if any additional requirements apply.

Nothing in this document may be used to implement any enforcement action or levy any penalty unless promulgated by rule under chapter 536 or authorized by statute.

For more information