The Buy Clean California Act (BCCA) (Public Contract Code Sections 3500-3505), states the Department of General Services (DGS) is required to establish and publish the maximum acceptable Global Warming Potential (GWP) limit for select construction materials. The BCCA targets carbon emissions associated with the production of structural steel (hot-rolled sections, hollow structural sections, and plate), concrete reinforcing steel, flat glass, and mineral wool board insulation. These materials must have a GWP that does not exceed the limit set by DGS.


July 27, 2021: A new assembly bill (AB-137, Sections 23-25) was signed into law on July 16, 2021 extending the implementation date of the BCCA.

New key legislation dates:

  • January 1, 2022:  DGS will publish the maximum acceptable GWP for eligible materials.
  • July 1, 2022: Awarding authorities will gauge GWP compliance of eligible materials with the required Environmental Product Declaration (EPD).

GWP limits previously posted on this webpage are no longer in effect.

1.0 Environmental Product Declarations:

1.1 What is an Environmental Product Declaration, or EPD?

An Environmental Product Declaration (EPD) is an independently verified and registered document that reports a product’s environmental impact over its life cycle.

1.2 How do I obtain an EPD?

Contact a program operator to begin the EPD development process. A manufacturer will need to conduct a product life cycle assessment and utilize a program operator to verify and publish an EPD.

1.3 Where can I find a program operator?

Find program operators at the Program Operator Consortium and in the references and resources section below.

1.4 What environmental impact category does the Buy Clean California Act use as a metric?

The BCCA uses Global Warming Potential (GWP), which is reported as carbon dioxide equivalent (CO2-eq).

1.5 What is Global Warming Potential, or GWP?

Greenhouse gases (GHGs) are those that trap heat in the earth’s atmosphere. Carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs) are types of GHGs. While all GHGs have the effect of trapping heat, each gas has a different amount of impact. The various GHGs produced when manufacturing a product, for example, can be represented by an equivalent amount of carbon dioxide associated with the warming effect of a given quantity of a GHG. This amount is known as the global warming potential and is expressed as CO2-eq.

2.0 Eligible Materials:

2.1 What construction materials are affected?

Structural steel, concrete reinforcing steel, flat glass and mineral wool board insulation. Table 1 below describes the types of materials that can apply to the established GWP limits. Awarding authorities should be contacted for specific material requirements subject to the BCCA.

Table 1: Description of eligible materials

Eligible material


Structural steel

Hot-rolled sections consisting of wide flange beams (W-shape and HP-shape used in structural applications), standard beams (S-shape), misc. beams (M-shape), channels, angles, and tees.

Hollow structural sections with round, square, or rectangular cross-section.

Plate material.

Concrete reinforcing steel

ASTM A615/A615M standard specification for carbon steel bars.

ASTM A706/A706M standard specification for low-alloy steel bars.

ASTM A767/A767M standard specification for zinc-coated steel bars.

ASTM A775/A775M standard specification for epoxy coated steel bars.

Flat glass

Float or rolled glass that is clear or tinted.

Mineral wool board insulation

Board insulation made of rock or slag in light and heavy density categories.

Light density: 2.5 lbs / ft3 – 4.3 lbs / ft3

Heavy density: 4.4 lbs / ft3 – 8 lbs / ft3

lbs / ft3 is pounds per cubic foot.

2.2 Will any other construction materials be added to the BCCA?
It is likely that other materials will be added in the future.

3.0 Affected Awarding Authorities:

3.1 Which awarding authorities must comply with the BCCA?

The awarding authorities are the Department of Transportation, Department of Water Resources, Department of Parks and Recreation, Department of Corrections and Rehabilitation, Military Department, Department of General Services, Regents of the University of California, Trustees of the California State University and state agencies granted authority to work on public works projects under Management Memo 18-01.

4.0 GWP Limit:

4.1 Who is responsible for setting the GWP limit?

DGS, Procurement Division in consultation with California Air Resources Board.

4.2 How many limits will DGS establish?

There will be seven limits established for compliance by January 1, 2022:

  • Three for structural steel (one each for hot-rolled sections, hollow structural sections, and plate)
  • One for concrete reinforcing steel
  • One for flat glass
  • Two for mineral wool board insulation (one each for light- and heavy-density types)

4.3 Where will DGS obtain the data to establish the GWP limit?

DGS will obtain the data from publicly available EPDs.

4.4 How will the GWP limit be determined?

Legislation requires the limit to be set at the industry average of facility-specific GWP for that material. Prior to the required publication date, DGS will assess the data collected to date and determine the average.

Since EPDs have a level of uncertainty in the reported GWP, DGS will add a tolerance to the baseline average to establish the GWP limit.

4.5 Will DGS exclude the GWP contribution from material fabricators when establishing the GWP limit?

Yes. For the four material types identified in the BCCA, the majority of GWP production is attributed to the manufacturer of the material rather than the fabricator. Therefore, the GWP limit will be based on manufacturer’s impacts.

For example, a steel mill consumes much more energy to melt iron ore (or steel scrap) to form it into a steel beam than a typical fabricator whose operations would consist of welding, drilling, or finishing. GWP production is directly proportional to energy use.

4.6 Once the GWP limit is established, will it ever be changed?

Beginning on January 1, 2025, and every three years thereafter, DGS will review the maximum acceptable GWP for each material and may adjust the limit downward* to reflect industry improvements.

* The BCCA legislation prohibits DGS from adjusting the limit upward.

4.7 Where and when will the GWP limit be published?

The GWP limits will be published on this webpage by January 1, 2022.

5.0 Compliance:

5.1 Who needs to submit EPDs to awarding authorities?

The successful bidder for a public works project must submit EPDs for all eligible materials to the awarding authority awarding the contract.

5.2 Is there a particular type of EPD that must be submitted?

An EPD must meet certain requirements before an awarding authority can determine material compliance.

An EPD must be:

  • A facility-specific manufacturer declaration 
  • Independently verified in accordance with ISO 14025 (Type III environmental declarations – Principles and procedures)
  • Developed according to the guidelines of the applicable Product Category Rule (PCR) as identified by DGS
  • Validated by a date that has not expired
  • Represented as an eligible material (as described in Table 1, Section 2.0)

An EPD must not be:

  • An industrywide/industry-average product declaration
  • A fabricator’s product declaration
  • An average reported GWP from multiple manufacturing facilities

5.3 What is a facility-specific manufacturer EPD?

It is a product EPD in which the environmental impacts can be attributed to a single manufacturer and manufacturing facility.

5.4 What’s the difference between a manufacturer, a producer, and a fabricator?

With respect to the BCCA, a manufacturer is the entity that produces the basic construction material that typically requires additional processing by fabricators before use in a construction project.

Consider rebar, for example. A steel mill that melts steel and forms it into rebar would be viewed as a manufacturer, whereas a facility that turns straight lengths of rebar into shapes, bends, or welds rebar would be considered a fabricator.

The terms “manufacturer” and “producer” are used interchangeably by the BCCA implementation team.

5.5 What is a Product Category Rule, or PCR?

A PCR is a set of rules, requirements and guidelines used to develop an EPD for a product group.

5.6 Where can I find a PCR that pertains to the eligible materials identified in the BCCA?

The current PCRs are identified in the References and Resources section below.

5.7 When do EPDs need to be submitted to state agencies during the bid cycle?

Contact the awarding authority conducting the solicitation for specific requirements.

5.8 How long is my EPD valid?

The expiration date is determined by the program operator and identified within the EPD. An expired EPD will not be accepted for compliance.

5.9 When do bidders have to comply with the law?
Public works contracts awarded to a bidder on or after July 1, 2022 will have to comply to the BCCA if any of the eligible materials are used.

The following individuals can be contacted for specific awarding authority policies.

Department of Transportation
Jacquelyn Wong

Department of Corrections and Rehabilitation
Danette Verras

Department of Parks and Recreation
Sam Blackney

California State University
Jeremy Gomoljak

University of California
Anthony Cimo

Department of Water Resources
Brenda Albert

Military Department
Krista Hudson

DGS/Real Estate Services Division
Esmer Velagic 


Links to North American Program Operators, PCRs, and EPDs

Reference PCRs for eligible materials

Below are PCRs that can be used to develop EPDs for a wide variety of products within the eligible material category (i.e., structural steel, concrete reinforcing steel, flat glass, and mineral wool board insulation). Please refer to table 1 in the Frequently Asked Questions section above to understand exactly which products need to comply with the initial rollout of the Buy Clean California Act.


Structural steel and concrete reinforcing steel 

Title: Part B: Designated Steel Construction Product EPD Requirements 
Valid through: August 26, 2025 
Version: 2.0 
Program operator: UL Environment

Flat glass 
Title: NGA PCR for Flat Glass: UN CPC 3711 
Valid through: September 30, 2025 
Version: 2 
Program operator: NSF International

Mineral wool board insulation 
Title: Part B: Building Envelope Thermal Insulation EPD requirements 
Valid through: April 10, 2023 
Version: 2.0 
Program operator: UL Environment

 Local governments supporting the BCCA

The following local governments have issued executive directives and resolutions in support of the BCCA:





Engineering Branch

Department of General Services
Procurement Divsion

707 Third Street, Second Floor
West Sacramento, California 95605

To ensure that your questions receive accurate and timely responses, please provide your name, phone number, and agency/organization name.