MTI Continues to Engage on Air Quality in California
On June 18th, a local Southern California air district held its 7th working group meeting on proposed new rulemaking for all heat treat facilities. The South Coast Air Quality Management District (SCAQMD) is the nation’s largest air district covering 17 million people and jurisdiction over the counties of Los Angeles, Orange, San Bernardino, and Riverside.
SCAQMD is working on Proposed Rule (PR) 1435. The stated goal of PR 1435 is to reduce the risk of the toxic air contaminant: hexavalent chromium. The inhalation risk for hexavalent chromium is measured at 1 ng/m3, which is 5,000 times lower than the 8-hour Fed-OSHA worker standard. This significantly lower risk level for cancer is due to the potential of airborne hexavalent chromium entering local communities. Local communities can have infants, elderly, schools, hospitals, or other sensitive receptors with lower risk thresholds than an 8-hour adult worker. Currently, there are active air monitoring stations in Los Angeles County’s city of Paramount that measure and publicly report hexavalent chromium levels in the community. This data can be viewed at: www.paramountenvironment.org/air.
As previously stated, SCAQMD is currently on its 7th working group meeting for PR 1435. The first working group meeting for PR 1435 began on August 6, 2019. Subsequent working group meetings have been held on May 18, 2023, September 28, 2023, November 16, 2023, May 2, 2024, and September 5, 2024. All PR 1435 working group meeting presentations can be viewed at: www.aqmd.gov/home/rules-compliance/rules/scaqmd-rule-book/proposed-rules/rule-1435.
Previous versions of Proposed Rule 1435 required that all heat treat furnaces employ pollution control systems to control emissions from heat treat furnaces. A pollution control system uses a hood, ducting, and baghouse system with HEPA filtration to control the air with 99+% capture efficiency. If a hood and ducting is not feasible, the entire building must be enclosed and all of the air within the building must be pulled into a baghouse system with HEPA filtration. The cost of this system can reach over $1,000,000 when factoring in equipment, engineering, building improvements, installation, and maintenance.
MTI began working closely with the California Metals Coalition (CMC) in 2022. CMC is the nation’s largest state trade association serving all sectors of the metals industry. One of the key initiatives for MTI and CMC was to push back on the notion that all heat treat furnaces were the same and that pollution controls should be required on every type of furnace. The key to this argument is that the conversion of chromium to hexavalent chromium in a furnace requires heat and oxygen. Chromium may be present in the alloy being treated, the racks or baskets holding the parts, the refractory, or within the walls of a steel furnace. While all furnaces have heat, not all furnaces have oxygen with the chamber. An example would be a vacuum furnace vs. air furnace. MTI and CMC have held many meetings with SCAQMD staff, including site tours, to properly discuss these facts.
On June 18th, at the 7th working group meeting, SCAQMD staff acknowledged the distinction between furnaces and proposed pollution controls for only air furnaces, or more specifically, any furnace where oxygen is present in the chamber during the heating process. The 7th working group meeting also limited pollution controls to air furnaces that operate at or above 1250° F. Further specifics will be seen at a future SCAQMD working group meeting when proposed rule language is shared with stakeholders. A date for the next SCAQMD PR 1435 working group meeting has not been set.
MTI Members should take the proactive measure of internally documenting the type of heat treat equipment at your facility, if there is oxygen present in the chamber during the heating process, and if any of the equipment can be operated at or above 1250° F. Currently, if you are operating an air furnace in the SCAQMD jurisdiction at or above 1250° F, it is anticipated that these units will require a pollution control system to reduce the risk of hexavalent chromium emissions.
MTI is here to help. MTI has a committee monitoring this rule, studying the available air emissions data on heat treat furnaces, and working closely with our allies in California. Time is of the essence…we are available to talk to you about any aspect of the rulemaking.
Feel free to contact Tom Morrison at tom@heattreat.net if you have any questions.