Public Advisory Regarding Outdoor Metal Grinding Activities in the South Coast Air Basin

December 9, 2016

The South Coast Air Quality Management District (SCAQMD) is issuing this public advisory today regarding potential air quality impacts resulting from conducting metal grinding activities in the outdoors (open air).  Based on ongoing investigations and air sampling activities conducted by SCAQMD staff, it has been demonstrated that metal grinding activities conducted outdoors can cause odors and release metal particulate emissions to the outside air, affecting surrounding businesses and residents so as to cause a public nuisance in violation of SCAQMD Rule 402 and California Health and Safety Code Section 41700.  Also, depending on the toxicity of metals being grinded and/or the intensity and duration of the activity, metal grinding particulate emissions may increase health risks for receptors, which may also be a public nuisance.

To anyone conducting grinding operations outdoors:

The South Coast Air Quality Management District recommends that all metal grinding activities be conducted within a building to minimize the release of emissions to the public and prevent a public nuisance.  When relocating metal grinding activities indoors, appropriate ventilation is needed to ensure the grinding operation does not pose a safety hazard to workers.  Grinding emissions should be directed to pollution control devices that can filter metal particulate emissions and minimize impacts to the community.  The South Coast Air Quality Management District also recommends to either wet clean or use vacuum sweepers to clean any dust generated from grinding activities on a daily basis.

For public complaints regarding odors or nuisances from outdoor metal grinding activities or any other air quality related issues, call the SCAQMD Complaint Line at 1-800-CUT-SMOG or

For information relating to proposed SCAQMD regulations regarding metal grinding operations at forging facilities, click here.


SCAQMD is the air pollution control agency for Orange County and major portions of Los Angeles, San Bernardino and Riverside counties.