The California Air Resources Board (CARB) has released a Second 15-Day Notice for their Emergency Vehicle Emissions Regulations, providing additional refinements to the rulemaking package currently under consideration for permanent adoption. The proposed modifications do not change the underlying framework of the regulation, but according to the notice are intended to provide greater clarity and legal certainty.

Key changes include clarifying that CARB is not enforcing certain Phase 2 Greenhouse Gas (GHG) standards because no applicable U.S. EPA waiver exists, explaining how alternative compliance pathways would operate depending on future court decisions regarding the Advanced Clean Cars II (ACC II) and Omnibus waivers, replacing several alternative regulatory provisions with older versions that are clearly covered by existing EPA waivers, and making technical corrections to references, citations, and regulatory text.

The Emergency Vehicle Emissions Regulations were originally adopted in response to federal actions affecting California’s ACC II and Omnibus waivers. CARB established the regulations as a temporary backstop to ensure vehicle emissions requirements remained in effect while legal challenges proceed. The regulations were approved for permanent adoption by the CARB Board in March 2026 and were recently extended to remain in effect through September 30, 2026, while the permanent rulemaking process continues.

Stakeholders wishing to comment on the Second 15-Day changes must submit comments to CARB by July 15, 2026. You can visit CARB’s website for more details.