Proposed Amended Rule 1124 – Aerospace Assembly and Component Manufacturing Operations
Summary
SCH Number
2026040171
Public Agency
South Coast Air Quality Management District
Document Title
Proposed Amended Rule 1124 – Aerospace Assembly and Component Manufacturing Operations
Document Type
NOE - Notice of Exemption
Received
Posted
4/3/2026
Document Description
Rule 1124 regulates emissions of volatile organic compounds (VOC) from aerospace coatings, adhesives, sealants, lubricants, maskants, cleaning solvents, and strippers used in aerospace assembly and component manufacturing operations. Proposed Amended Rule (PAR) 1124 partially implements 2022 Air Quality Management Plan (AQMP) control measure CTS-01 – Further Emission Reductions from Coatings, Solvents, Adhesives, and Lubricants to phase out, or limit the use of, para-Chlorobenzotrifluoride (pCBtF) and tert-Butyl Acetate (t-Bac) in aerospace materials due to toxicity concerns. PAR 1124 establishes a prohibition and compliance schedule for the phase-out of aerospace materials that do not rely on pCBtF and t-BAc (Level I materials) while maintaining existing VOC content limits for all aerospace material categories except for the low-use adhesion promoter subcategory; with alternative compliance options for aerospace materials that rely on pCBtF and t-BAc (Level II materials). Specifically, PAR 1124 proposes: 1) a two-tiered alternative compliance framework that classifies aerospace materials into Level I and Level II materials; 2) a future pCBtF and t-BAc prohibition for Level I materials with sell-through and use-through provisions to address stranded asset concerns; 3) an increase to the VOC limit from 250 grams per liter (g/L) to 750 g/L, or alternative reactivity-based VOC limit for adhesion promoters and maskants; 4) clarifications and updates to definitions, rule structure, supply and sales provisions, and test methods; and 5) updates to recordkeeping requirements including labeling requirements. PAR 1124 also contains the following alternative compliance options for Level II materials which are designed to protect public health while allowing limited, continued use of certain critical aerospace coatings that contain pCBtF or t-BAc by: 1) installing new or modifying an existing air pollution control system capable of achieving at least 95 percent control efficiency and meeting receptor-based usage limits; 2) applying for a low-use permit limit; or 3) phasing out the use of pCBtF and t-BAc and transition to alternatives according to specified timeframes. Implementation of PAR 1124 is expected to result in an overall net decrease in VOC emissions of 0.008 ton per day (tpd) due to: 1) an increase of VOC emissions from adhesion promoters by approximately 0.004 tpd; and 2) a concurrent decrease of VOC emissions of approximately 0.012 tpd from the largest facilities operating air pollution control systems. Phasing out and limiting pCBtF and t-BAc emissions in PAR 1124 will benefit workers, nearby receptors, and the public by reducing the potential risk of exposure to these toxic chemicals.
Contact Information
Name
Farzaneh Khalaj
Agency Name
South Coast AQMD
Job Title
Air Quality Specialist
Contact Types
Lead/Public Agency
Phone
Email
Location
Counties
Los Angeles, Orange, Riverside, San Bernardino
Regions
Countywide
Other Location Info
The proposed project is located within the South Coast Air Quality Management District’s (South Coast AQMD) jurisdiction, which includes the four-county South Coast Air Basin (all of Orange County and the non-desert portions of Los Angeles, Riverside, and San Bernardino counties), and the Riverside County portion of the Salton Sea Air Basin and the non-Palo Verde, Riverside County portion of the Mojave Desert Air Basin.
Notice of Exemption
Exempt Status
Other
Type, Section or Code
15061(b)(3)
Reasons for Exemption
South Coast AQMD, as Lead Agency, has reviewed the proposed project (PAR 1124) pursuant to: 1) CEQA Guidelines Section 15002(k) – General Concepts, the three-step process for deciding which document to prepare for a project subject to CEQA; and 2) CEQA Guidelines Section 15061 – Review for Exemption, procedures for determining if a project is exempt from CEQA. It can be seen with certainty that there is no possibility that implementation of PAR 1124 may have a significant adverse effect on the environment because the estimated increase in VOC emissions from adhesion promoters due to a revised VOC emission limit will be fully offset by concurrent decreases in VOC emissions from some facilities installing new or modifying existing air pollution control systems which will result in an overall net decrease of VOC emissions. Therefore, the proposed project is exempt from CEQA pursuant to CEQA Guidelines Section 15061(b)(3) – Common Sense Exemption.
County Clerks
Los Angeles, Orange, Riverside, San Bernardino
Attachments
Notice of Exemption
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