There are several different types of permits depending on the type of activity and pollutants involved. The following list explains each different type of permit.

Air Class I Permits

Class I permits are issued to any source that meets the requirements of ¹A.A.C. Title 18, Chapter 2, Article 302(B)(1) . Such sources include:
Any Major Source - A "major" source as defined by the ²A.A.C. Title 18, Chapter 2, Article 101(64)  is any source that has the potential to emit 100 tons per year of any criteria air pollutant . A source is also considered major if it has the potential to emit 10 tons per year of any single Hazardous Air Pollutant or 25 tons per year of any combination of Hazardous Air Pollutants.


Air Class II Permits

Class II permits are issued to sources that do not qualify for Class I permits and that meet the requirements of ³A.A.C. Title 18, Chapter 2, Article 302(B)(2). Such sources include: Sources that have the potential to emit significant quantities of regulated air pollutants as defined in ⁴A.A.C. Title 18, Chapter 2, Article 101(104)(a).
 Sources that are subject to Sections 111 or 112 of the Clean Air Act except for the standards listed at ⁵A.A.C. Title 18, Chapter 2, Article 302 (B)(4)(b) and (c) .

Air General Permits

A general permit is a pre-approved permit that covers a specific class of sources. A general permit differs from an individual permit in that it can be applied to more than one source, is usually more restrictive, less expensive, and requires a shorter period of time for the processing and issuance of an Authorization to Operate (ATO). By the issuance of a general permit, the Department indicates that it approves the activities authorized by the general permit, provided that the owner or operator of the source, applies with the Department and meets the requirements of the general permit.
When a source applies for coverage under an individual permit it must go through its own public notice and possibly a public hearing. Since the general permit is written to cover sources that are similar, it must go through public notice and public hearing only once. Each source that is covered by the general permit will not be required to go through its own public notice and public hearing.

Once a general permit has been developed, sources may apply for coverage under the general permit instead of obtaining individual permits. If the sources meet the criteria for coverage under the general permit, an Authorization to Operate (ATO) is issued for each major piece of equipment covered under the permit. The ATO allows for easy tracking of permitted equipment and assists inspectors in verifying coverage while conducting inspections.

Air Title V Permits

Title V is a portion of the 1990 Clean Air Act Amendments, which outlines the Operating Permits Program. The Operating Permits Program was made into law to uniformly limit the emissions from major sources of criteria air pollutants  throughout the United States. This requires states to implement permit programs at least as stringent as federal requirements to avoid federal sanctions. A default federal permit program is implemented in those states that fail to implement their own federally-approved permit program, ensuring that all major sources must comply with the applicable federal Clean Air Act regulations. The federal U.S. Environmental Protection Agency (EPA)  has the power to overrule state permit decisions to ensure compliance.
Under Title V all major sources must apply to the state in which the source resides for an air quality control permit. These sources must submit plans showing compliance with all the applicable Clean Air Act regulations. The state must then review the plans and application for compliance and subsequently draft a permit. The permit must be reviewed by the appropriate regulatory agencies, nearby states (when applicable), and by the U.S. EPA.

Arizona has received approval for the federal Title V permit program, established by the 1990 federal Clean Air Act Amendments.

Air Prevention of Significant Deterioration (PSD) and New Source Review (NSR)

As mandated by the Clean Air Act, new major stationary sources of air pollution and major modifications to existing sources must obtain air quality control permits before starting construction. When sources in attainment areas apply for such permits, they are referred to as PSD permits. Sources that are in non-attainment areas apply for such permits, they are referred to as non-attainment area NSR permits.

• Map of Arizona PSD Minor Source Baseline Dates for Air Quality Control Regions: PM, SO2 and NO2

The main goals of attainment area PSD regulations are designed to ensure that:

• To ensure that economic growth will occur in harmony with the preservation of existing clean air resources.
• To protect the public health and welfare from adverse effects which might occur even at air pollution levels better than the national ambient air quality standards.
• To preserve, protect, and enhance the air quality in areas of special natural recreational, scenic or historic value.

The main goals of non-attainment area NSR regulations are designed to ensure that:

• A new source's emissions will be controlled to the greatest degree possible.
• More than equivalent offsetting emissions reductions will be obtained from existing sources.
• There will be progress toward achievement of attainment status.