Summary
Cut through the green tape
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Details
- California
The Buy Clean California Act is designed for use on state-funded construction projects. It applies to any contractor or supplier that provides covered materials, requiring them to document and disclose the climate impacts of those products through Environmental Product Declarations (EPDs).
Deep dive
Introduction
The Buy Clean California Act (AB 262) is a state law that uses public procurement to cut the embodied carbon of construction materials on state-funded projects. Signed in 2017 and now codified in California Public Contract Code §§3500–3505, it directs the Department of General Services (DGS), in consultation with the Air Resources Board (CARB), to set maximum global warming potential (GWP) limits for key materials such as structural steel, reinforcing steel, flat glass and mineral wool insulation.
Unlike voluntary green-building labels or management standards, Buy Clean is a binding procurement rule: if materials exceed the GWP limits, they cannot be used on covered state projects. The core idea is simple: use the state’s infrastructure budget to favour lower-carbon manufacturers and reward suppliers who can prove their climate performance with credible Environmental Product Declarations (EPDs).
Reporting implications for companies
For suppliers, Buy Clean California creates concrete climate-reporting duties tied to bidding on state work. To show compliance with the GWP limits, contractors must provide EPDs for eligible materials used on covered projects.
In practice, that means:
Obtain facility-specific, third-party-verified EPDs for structural steel, reinforcing steel, flat glass and mineral wool board insulation you plan to supply.
Check GWP values in each EPD against the latest DGS maximum GWP limits before bidding or installing materials.
Submit EPDs as part of bid documents or pre-installation submittals, following any agency-specific procedures (for example, Caltrans and the University of California issue detailed guidance).
Keep records and update EPDs over time, as products, production sites or mix designs change.
DGS supports implementation through its EPD Compliance Guide, GWP-limit reports, FAQs and webinars, while agencies add their own project-level instructions.
Current status and future outlook
The Buy Clean California Act is in force and operational, but still evolving. The law was signed in 2017, basic obligations took effect in 2019, and the first official GWP limits for eligible materials were published in 2022 after an initial data-collection period. DGS has since issued a detailed GWP Adjustment Study and must review the limits at least every three years.
Other policies, such as emerging “Buy Clean” rules for concrete and Caltrans’ own EPD procedures, are extending the concept to more materials and project types. Looking ahead, suppliers can expect: tighter, more data-driven GWP limits as facility-specific EPDs become common, and wider uptake as local governments, universities and large private owners voluntarily adopt Buy Clean-style criteria in their own procurement.
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