Nine Metal Fabrication and Finishing Source Categories 

The NESHAP XXXXXX or 6X rule — applies to "Nine Metal Fabrication and Finishing Source Categories" — It impacts area sources with a specific SIC or NAICS that emit five targeted metal fabricating or finishing HAP metals as part of any of five different processes. To determine if the NESHAP 6X rule applies to your facility (or sources), review and answer the following questions: 

  1. Is the facility an area source of hazardous air pollutants, or HAPs? An area source is defined as one that emits less than 10 tons of a single HAP or less than 25 tons of a combination of HAPs annually. If you are an area source of HAPs, proceed to question 2.  

  1. Is the source’s primary activity at the facility in one of the nine source categories? Check source NAICS and correlating SIC codes against codes on this table.  If your NAICS and matching SIC is not on this table, then this rule does not apply at your facility. If your NAICS and matching SIC are on the table, then proceed to questions 3 and 4 to determine applicability. 

  1. Does the source perform one or more of the regulated processes? The five regulated processes include dry abrasive blasting, dry grinding and dry polishing with machines, machining (dry metal turning, milling, drilling, boring, tapping, planing, broaching, sawing, cutting, shaving, shearing, threading, reaming, shaping, slotting, hobbing and chamfering with machines), spray painting and welding.  

  1. If answers to questions 2 and 3 are yes, then do any of the processes listed above emit one or more of the five HAP metals, including compounds of cadmium, chromium, lead, manganese and nickel, or any of these metals in the elemental form with the exception of lead? 

If questions 1-4 above were all answered yes, then the 6X rule applies. If you have questions, contact your state SBEAP.  

EPA resources 

State-specific resources  

Vendor and other resources  

Helpful compliance videos 

Visible Emission Monitoring Tutorial - Welding

Use this tutorial to help learn how to monitor your visible emissions to help reduce and control your emission amount for welding businesses.


Visible Emission Monitoring Tutorial - Dry abrasive blasting

Use this tutorial to help learn how to monitor your visible emissions to help reduce and control your emission amount for businesses that do dry abrasive blasting.


Requirements for the 6X Area Source Rule

This recorded webinar does an overview of the 6X area source rule, including but not limited to compliance due dates, operation, recordkeeping, and reporting requirements.


Implementation tools for 6X Area Source Rule

This recorded presentation gives an overview of the air-quality regulation known as the 6x rule, and tools your factuality can use to comply with it.