Chapter 173-446 WAC – Cap-and-Invest Offsets - Ozone Depleting Substance Protocol
On July 21, 2025, Ecology adopted amendments to address new and revised offset protocols in the Climate Commitment Act Program Rule, Chapter 173-446 WAC. We adopted amendments in sections 173-446-505 (Requirements for compliance offset protocols) and 173-446-580 WAC (Invalidation of ecology offset credits). Offsets are projects or programs designed to reduce the amount of greenhouse gases in the atmosphere. In Washington’s Cap-and-Invest Program, offset projects must also provide direct environmental benefits to our state. Offsets allow businesses to balance out the negative impacts of their emissions by funding a project that benefits the environment. For addtional information, visit our site on Cap-and-Invest offsets.
This adopted rule updates the Ozone Depleting Substances (ODS) protocol and will increase technical standards, decrease obstacles to project development, and reflect policy advances. The ODS protocol is a separate document that is adopted by reference in the rule. The adopted protocol is based on a protocol that the California Air Resources Board previously adopted (Compliance Offset Protocol Ozone Depleting Substances) and incorporates the following changes:
- Update Global Warming Potential values from Update Global Warming Potential values from the Fourth IPCC Assessment Report (AR4) to the Fifth IPCC Assessment Report (AR5).
- Allow ODS sourced from the federal government.
- Allow credit generation from Hydrochlorofluorocarbon-22 (HCFC-22).
- Allow credit generation from medical aerosols and unused solvents
In addition to the ODS protocol (Offsets) rulemaking, Ecology is engaging in rule development to update the forestry offsets protocol.
Rulemaking timeline
Announcement phase (CR-101)
Filing date:
Sept. 12, 2023
Announcement documents
Rule development phase
Sept. 12, 2023 – Early 2025Public input & involvement
We have held public meetings to provide information about the rulemaking and seek your input.To get updates about these meetings and this rulemaking, join our email list.
Ozone Depleting Substances Draft rule language (most recent)
Public comment period (informal)
Nov. 9, 2023, at midnight – Sept. 27, 2024, at 11:59 p.m.
Read comments about which offset protocols should be revised or added, and about the scope of this rulemaking.
Public comment period (informal)
Oct. 1, 2024, at noon – Oct. 31, 2024, at 11:59 p.m.
Read comments about the draft rule language and considered revisions to the ODS protocol.
Rule proposal phase (CR-102)
Feb. 12, 2025
- Proposal notice – CR-102 form
- Proposed rule language
- Preliminary Regulatory Analyses
- Proposed compliance offset protocol
- SEPA Determination of Non-Significance (DNS) and Environmental Checklist
Comment period
Comments were due April 4, 2025, at 11:59 p.m. Please see submitted comments here.
Our public hearings began with a short presentation and a question-and-answer session, followed by the opportunity to provide testimony.
Watch them on YouTube:
Rule adoption phase (CR-103)
July 21, 2025
Aug. 21, 2025
Related links
Contact information
Kayla Stevenson
Environmental Planner
kayla.stevenson@ecy.wa.gov
360-972-0313
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Accessibility
To request ADA accommodation for disabilities, or printed materials in a format for the visually impaired, contact Ecology's ADA Coordinator by email at ecyadacoordinator@ecy.wa.gov, or call 360-407-6831. People with impaired hearing may call Washington Relay Service at 711. People with speech disability may call TTY at 877-833-6341.