Over several years, staff has conducted research and worked with voluntary standards organizations concerning the risk of injury and death associated with carbon monoxide (CO) production and leakage from residential gas furnaces and boilers. This proposed rule would establish a performance requirement, under which gas furnaces or boilers would be required to shut off or modulate when CO levels reach a specified level for a specified duration of time. In 2019, the Commission issued an advance notice of proposed rulemaking (ANPRM) to initiate rulemaking under the Consumer Product Safety Act and requested comments on the risk of injury and alternative approaches to address the risk. On September 24, 2021, the Commission voted to change the fiscal year 2022 deliverable from a notice of proposed rulemaking (NPRM) to Data Analysis and/or Technical Review (DA/TR). On February 9, 2022, staff provided a summary and status update in a public briefing to the Commission.   On September 25, 2023, staff sent an NPRM briefing package to the Commission.  On October 11, 2023, the Commission approved publication of the NPRM in the Federal Register.  On February 21, 2024, the Commission provided an opportunity for interested parties to make oral presentations on the NPRM.  The hybrid hearing was held in person at CPSC's headquarters and remotely via webinar.  Staff is redacting data for release for additional public comment and will make those available for public comment in a forthcoming Notice of Availability (NOA). The Fiscal Year 2024 Operating Plan calls for staff to submit a Final Rule package to the Commission in fiscal year 2024.