The Buy Clean California Act (BCCA) (Public Contract Code Sections 3500-3505), states the Department of General Services (DGS), in consultation with the California Air Resources Board (CARB), is required to establish and publish the maximum acceptable Global Warming Potential (GWP) limit for four eligible 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. When used in public works projects, these eligible materials must have a GWP that does not exceed the limit set by DGS.


  • Maximum acceptable GWP limits were established on January 1, 2022 and can be found in the GWP Limits section below.
  • Beginning July 1, 2022, the awarding authorities will determine GWP limit compliance of eligible materials using Environmental Products Declarations (EPDs).
  • The BCCA legislative report describing the methodology to establish the GWP limits can be found on the DGS Legislative Reports webpage in the 2022 folder.

Table 1: GWP limits for eligible materials

Eligible material

Maximum acceptable GWP limit (unfabricated)*

Hot-rolled structural steel sections

1.01 MT CO2 eq./MT

Hollow structural sections

1.71 MT CO2 eq./MT

Steel plate

1.49 MT CO2 eq./MT

Concrete reinforcing steel

0.89 MT CO2 eq./MT

Flat glass

1.43 MT CO2 eq./MT

Light-density mineral wool board insulation

3.33 kg CO2 eq./1 m2

Heavy-density mineral wool board insulation

8.16 kg CO2 eq./1 m2

*MT is metric ton.

DGS leveraged current industrywide EPDs to determine the industry average and set the final limit above.

1.0 Environmental Product Declarations:

1.1 What is an Environmental Product Declaration, or EPD?

An 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. Stakeholders are not restricted to using the program operators referenced on this webpage.

1.4 What environmental impact category does the BCCA use as a metric?
The BCCA uses GWP, which is reported as carbon dioxide equivalent (COeq.).

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 (GWP) and is expressed as COeq.

2.0 Eligible Materials:

2.1 What construction materials are affected?

Structural steel, concrete reinforcing steel, flat glass and mineral wool board insulation. Table 2 below describes the types of eligible materials that can apply to the established GWP limits. Awarding authorities should be contacted for specific material requirements subject to the BCCA.

Table 2: 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 types. 


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 additional legislation will add more materials 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 was responsible for setting the GWP limit?

DGS' Procurement Division in consultation with CARB.

4.2 How many limits did DGS establish?

Seven limits were established for compliance:

  • 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 did DGS obtain the data to establish the GWP limit?

DGS obtained the data from publicly available EPDs.

4.4 How was the GWP limit determined?

DGS set the limit at the industry average of facility-specific GWP for that material.

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

Yes. For the four eligible material types identified in the BCCA, the majority of GWP production is attributed to the manufacturer of the material rather than the fabricator.

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 Now that the GWP limit has been established, will it ever change?

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. 

5.0 Compliance:

5.1 Who needs to submit EPDs to awarding authorities?

Contract the awarding authority conducting the solicitation for specific submittal requirements.

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 FAQ Section 2.0, Table 2)

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 are disclosed for a single manufacturer and single manufacturing facility. This EPD may disclose the GWP for more than one manufacturing facility as long as each facility's GWP is kept separate.

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 bends, welds, or turns straight lengths of rebar into shapes 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 submittal 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 BCCA?
Public works contracts awarded to a bidder on or after July 1, 2022 will have to comply if any of the eligible materials are used.

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

Department of Transportation
Delia Aguirre

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
Blakely Nordman

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 FAQ Section 2.0 (Table 2) above to understand exactly which products need to comply with the initial rollout of the BCCA.


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:

  • Los Angeles      Executive Directive No. 25
  • Berkeley            Resolution No. 68,893-N.S
  • Cupertino          Resolution No. 19-040
  • Richmond         Resolution No. 68-18





Engineering Branch

Department of General Services
Procurement Divsion

707 Third Street, Second Floor
West Sacramento, California 95605

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