Colorado Air Quality Control Commission Regulation 29 restricts all government entities (state agencies, local governments, municipalities, counties, public school districts, special districts) and their commercial contractors from using gas-powered handheld lawn and garden equipment during the summer ozone season (June 1 – August 31) in the Denver Metro / North Front Range ozone nonattainment area. Covered equipment includes aerators, brush cutters, chainsaws, push mowers, leaf blowers, power washers, rotary tillers, shredders, string trimmers, and similar push / hand-held gas equipment. The rule went into effect June 1, 2025 (Denver Gazette, Jun 5 2025). Residential and most private commercial use remain unrestricted. Colorado has not adopted a CARB-equivalent sales ban. Boulder, after a multi-year study, deferred regulatory action in favor of a voluntary voucher pilot.