Welding operations emit air contaminants and require a permit to operate unless they are exempt under District Rule 11. The following information will assist in the completion and submittal of an application. Each section of the page contains important information needed to process an application. 

Permit applicability for welding operations is more complex than some other equipment types and is based on multiple factors including the dates that welding operations began or emissions increased at each facility as well as the type and quantity of toxic emissions and health impacts to the surrounding community. Please see the Rules and Regulations section below for a detailed explanation of permit applicability or contact the District for assistance.

IMPORTANT NOTE: If you are applying for a permit due to receiving a permit applicability letter, see notes added in relevant sections to assist with the application process.

The District collects information about equipment and processes that are required to have a permit by asking for completion of application forms. These forms tell us about your operation and allow us to permit your process. It is very important that these forms are filled out completely and accurately. Errors and missing information may lead to delayed processing time and additional charges if revisions are required. Please carefully review and complete the forms. You may contact the District with any questions.

General Application: Word PDF

Welding Operations Supplemental Form Word PDF

Toxics Form: Word PDF

Other required attachments:

  • Historical welding rod usage data (if claiming an exemption from Rule 1200 for any emissions)
  • SDS or other composition data for welding rods where custom emission factors are proposed

The general and equipment specific application forms must be submitted with each application packet.

NOTE: For applications submitted in response to a permit applicability determination letter, applications are not required to include any information that has already been submitted to the District such as welding usage data and historical records.

NOTE 2: If your application will include an emission increase beyond historical existing emissions/operations, please list existing and proposed new material usage on two separate supplemental forms for clarity.

The correct fee must be submitted with your application in order for it to be accepted. For this type of equipment, depending on the application type, estimated fees are listed in the table(s) below depending on the expected work involved, and are determined based on the time and materials required to conduct the review. A fee estimate must be obtained from the District prior to submittal. Please note that the fees listed in these tables are estimated and the final fee may be more or less than this amount based on time and materials spent processing the application. The District maintains work records for this purpose.

Fee Tables

Initial application for existing operation w/o toxics increase (no current APCD permits)
Initial application for existing operation w/ toxics increase (no current APCD permits)
Initial application for existing operation w/o toxics increase (current APCD permits)
Initial application for existing operation w/ toxics increase (current APCD permits)

Before submitting an application, contact the District (see Assistance tab) to obtain an application fee estimate for application submittal. Please note that an additional fee may also apply depending on the method of payment. A breakdown of how the application fee(s) are determined can be seen here. Additional information can be found in District Rule 40.

How to Pay

These fees may be paid by check payable to "Air Pollution Control District" or by credit card (Visa, MasterCard, Discover, and American Express).

If you choose to email or fax your application and intend on paying with a credit card, ensure that you have obtained your fee estimate and have it in hand, and then after submitting the application, you must contact the District over the phone at (858)586-2600 to provide payment information.

Please note that credit card payments are assessed a transaction fee of 2.19% that is charged by the credit card provider.

Citizen Access
Select equipment type applications can now be submitted online.

Fax: (858) 586-2601

Permit Processing
10124 Old Grove Rd
San Diego, CA 92131-1649

The District will act on complete applications as soon as possible but at most within 180 days. The engineer assigned to your application will review it and contact you within 30 days of receipt to confirm that it is complete or request additional information. Typically permits are issued in about 60 days. More complex processes will take longer. Common reasons that applications may take longer than 60 days to evaluate include: the project is a complex project specifically at a major source, if the project requires a mandatory public notice period due to being installed within 1000 feet of a school or triggering the requirement for a air quality impact analysis (AQIA), if they do not initially pass a health risk assessment (HRA) or AQIA, if BACT is not proposed or complete BACT analysis is not submitted or for major sources if actual emission data is not included.

Ensuring your application is complete is the best way to reduce processing time. Complete emissions data is the most important factor in minimizing application processing time and iterative information requests. If you have any questions about what information is required, please contact the District using the information on the Assistance tab.

Sign up for Citizen Access to get up to date information on the status of your application.

Learn more about the permitting process and what to expect.

Best Available Control Technology

If a piece of equipment or a process emit more than 10 pounds per day of particulate matter (PM10), oxides of nitrogen (NOx), volatile organic compounds (VOC) or oxides of sulfur (SOx), the application must include a best available control technology (BACT) analysis. Large coating operations have the potential to emit more than 10 pounds per day of VOC. Please indicate on your application if your operation will emit more than 10 pounds per day of VOC.

If you have questions or need assistance reference the contact information on the assistance tab. Please review District Rules 20.1 and 20.2.

Note: Most welding operations are not subject to BACT requirements.


District Rule 1200 applies to any new, relocated, or modified emission unit which may increase emissions of one or more toxic air contaminant(s). The proposed project must comply with Rule 1200. Proposed equipment may require toxics best available control technology (TBACT) depending on the project. Please review District Rule 1200 for further details.

Note: Rule 1200 requirements apply to emission increases only, so do not apply to existing operations not applying to increase emissions.

Trade Secret

District rules address how information that is submitted to the District is managed. District Regulation IX contains District Rules 176 and 177. Please refer directly to these rules when submitting trade secret information. However, be aware that you will need to submit:

  1. You must indicate on the general application form that your submittal includes trade secret information to ensure that it is not inadvertently made publicly available.
  2. A letter disclosing the proprietary information. Ideally, this information should be separated from your application and clearly identifiable. This can be submitted electronically, and can be a separate submittal from the main application package.
  3. A letter for the  public record explaining why the information needs to be held as trade secret or is otherwise exempt from disclosure.

Applications submitted with incomplete material composition data due to failure to include proprietary information can significantly delay permit applications. In an effort to expedite the permit application process it is recommended that you contact the manufacturer or vendor of any proprietary materials that are used in the process and prepare the required letters as part of your application submittal.


In 1989, the California state legislature passed a law, AB 3205, designed to protect schoolchildren from hazardous air contaminants. The law, as currently written, requires the District to notify parents of schoolchildren, neighboring businesses and residents of all new or modified equipment that emits any hazardous air contaminant into the air which will be installed within 1,000 feet of a school site. The law also requires the District to consider any comments before authorizing construction. Please review your proposed location. If a school property boundary is located within 1,000 feet of the proposed emissions point, the AB3205 process will be initiated. This process requires a 30 day public comment period and the overall process will delay projects by at least six weeks.


NESHAP, NSPS and ATCMs are federal and state rules that apply to certain equipment types. Most welding operations are not subject to requirements under one of these rules unless part of a larger operation that is otherwise subject.

District Rules

Some welding operations are exempt from permitting and some require permits. There are two provisions of District rules that control whether or not your operation requires a permit.

Rule 11(d)(7)(iv) exempts “Brazing and welding equipment, including arc welding equipment and laser welding” from requiring a permit.


Rule 11(a)(5) states that the above exemption does not apply to equipment that was constructed or modified to increase emissions after November 15, 2000 and emits toxic air contaminants which may cause health impacts above thresholds which are described in Rule 1200.

The meaning of these two provisions together is that:

(a) Older welding operations (those which have not been modified and have not increased emissions since November 15, 2000) are exempt from permitting.
(b) All other welding operations that do not cause excessive health impacts to the surrounding community are also exempt from permitting.
(c) Any operation which does not fit unto the above categories requires a permit.

Additionally, because permit applicability is based on health risk, certain factors impact the need to obtain a permit including amount and type of welding materials used, and distance to nearby residences and businesses.

To assist with permit applicability, the District has made a calculation tool available on it’s website to show how health risk from your facility is determined. 

General rules that may apply to welding operations include Rules 50 and 51.

A complete listing of the District's rules can be found here.

Calculation Procedures and Additional Resources

Equipment Calculation Procedures - This page contains procedures to be used for calculating emissions from this equipment that should be submitted with each application.

Use of these calculation procedures will aid in minimizing application review time and costs.  The correct emission factors should be selected from the list based on equipment. If available, manufacturer provided equipment specific emission data or source test results should be utilized before using default emission factors. Sources of all emission data used must be included as attachments to the application.

AP-42 - An alternative compilation of emission factors and calculation procedures prepared by the EPA that may be utilized by the District in some situations for some equipment types.

Compliance Information

Call Duty Engineer
(858) 586-2600

District Small Business Assistance Program Coordinator
(858) 586-2650