Metal fabrication and finishing businesses perform work regulated by federal and state air regulations, including welding, shot or sand blasting, and painting and coating.
If abrasive blasting activity is part of your manufacturing or processing, you may need to follow the Industrial Process Equipment Rule. For example, blasting may need to be performed in a room or booth where the air is filtered. Use the abrasive blasting calculator to see what is required of your business. The MPCA requires facilities to prevent dust from becoming airborne; airborne dust is a nuisance and a health concern.
Some metal fabrication and finishing operations at your business may not be significant sources of air emissions. When evaluating your air emissions, check the insignificant activities rule to see if your equipment or activities are listed.
- If not, use this calculator to see if your activities qualify as conditionally insignificant and your business may be eligible as an Insignificant Facility: Mechanical finishing conditionally insignificant activity (p-sbap5-40mf)
- Otherwise, a registration air permit may be the best fit for your business.
In addition to mechanical finishing, businesses using paints, stains, solvents, or other volatile organic compound (VOC) containing materials may need an air permit based on the amount that is used. Using less than 1,000 gallons per year may be considered a conditionally insignificant activity. Using less than 2,000 gallons per year may qualify to operate without a permit by following certain technical standards or apply for a Registration Option B air permit. If your business uses more than 2,000 gallons of VOC-materials, has a higher air emission potential, or has other activities that emit air pollutants, you may qualify for the Registration Option D permit.
Complying with state permits
- How to comply with your Option B permit (aq3-03)
- How to comply with your Option D permit (aq3-04)
- How to calculate 12-month rolling sums (p-sbap5-34)
Air permit due dates
|Emission inventory fee for previous year||Mailed to permit holders in March, due within 60 days|
|Emission inventory||April 1|
|Corrections to emission inventory||Mailed to permit holders in November, due within 45 days|
Regardless if your business has an air permit, you may need to meet the requirements of National Emission Standards for Hazardous Air Pollutants (NESHAP)
The Metal Fabrication and Finishing Source Categories (6X) NESHAP focuses on blasting, machining, grinding, painting, and welding activities that release specific metal hazardous air pollutants. If the SIC or NAICS code for your business is listed here, the standard may apply to you. Review the EPA flow chart to see what you need to do.
If this standard applies, submit
Initial notification and first certification of compliance (see compliance section)
120 days after startup
The Paint Stripping and Miscellaneous Surface Coating Operations (6H) NESHAP affects facilities that spray paint onto metal, wood, or plastic or use methylene chloride to remove paint. Paints and solvents contain VOCs and hazardous air pollutants.
If this standard applies, submit
180 days after startup
The Surface Coating of Miscellaneous Metal Parts and Products (4M) NESHAP affects larger facilities that spray paint onto or coat miscellaneous metal parts. If you have a registration air permit, the 4M NESHAP does not apply to you.
You need a hazardous waste license if your business produces any amount of hazardous waste. Facilities in Anoka, Carver, Dakota, Hennepin, Ramsey, Scott, or Washington County are licensed and inspected by their county. Facilities in greater Minnesota are licensed and inspected by the MPCA. If you produce only small amounts of hazardous waste, you probably qualify to bring the wastes to Very small quantity generators collection programs (w-hw2-51). See the Hazardous waste documents and forms page for information on managing specific types of hazardous waste, such as:
- Wastes from sandblasting and power washing
- Paint booth filters
- Scrap metal
- Fluorescent lights
- Towels and rags
Annual hazardous waste training is required for businesses that generate 220 pounds or more of hazardous waste a month. Learn more on the General environmental requirements page.
Hazardous waste due dates
|Hazardous waste generators fee||Mailed to license holders in first quarter, due date on invoice|
|License application||Due August 1 for Greater Minnesota businesses;
Twin Cities metro businesses, contact your county
Apply for an industrial stormwater permit if you have material, equipment, or activities that are exposed to rain, snow, or runoff. You may qualify for the no-cost no-exposure certification and avoid the permit and fees if you don’t have any materials, equipment, or activities exposed to the elements. If you have only a few materials outside, consider moving them inside to qualify for no-exposure certification. Learn about stormwater pollution prevention ideas for metal fabricators and finishers.
Stormwater permit due dates
|Annual Report Form NPDES/SDS General Stormwater Permit for Industrial Activity||March 31|
|Industrial stormwater quarterly sampling||January 21, April 21, July 21, and October 21|
Be sure to check with your county, city, and township to see if they have any additional requirements.
Create a floor management plan to help you inspect and maintain floors to help prevent the release of hazardous materials.
- Floor Management Plan for the metal finishing industry
- Floor Management Plan
- Floor Inspection Checklist
MnTAP offers many ideas and personalized assistance for reducing wastes and saving energy at metal fabricating and finishing facilities.