The Trump administration announced on Tuesday that it planned to relax a Biden-era rule that requires grocery stores, air-conditioning companies, semiconductor plants and others to sharply and rapidly reduce some powerful greenhouse gases used in cooling equipment.

The Environmental Protection Agency plan would unravel what many industry leaders and environmentalists view as a rare success for the climate: a bipartisan agreement that those man-made chemicals, known as hydrofluorocarbons, or HFCs, should be rapidly phased down.

HFCs, which are commonly referred to as super pollutants, are thousands of times more potent than carbon dioxide at warming the planet.

But Lee Zeldin, the E.P.A. administrator, said the Biden administration’s plan for cutting the production and consumption of the chemicals, which aimed for an 85 percent reduction by 2036, did not give companies enough time to meet their deadlines. He said the rapid switch to other refrigerant blends had caused shortages that left families without air-conditioning in hot summer months, a claim the air-conditioning industry has said is exaggerated.

“With this proposal, E.P.A. is working to make American refrigerants affordable, safe, and reliable again,” Mr. Zeldin said in a statement.

The proposal came just hours before an expected government shutdown amid a deadlock between President Trump and Democrats over spending. If an agreement is not reached and federal employees are furloughed, work on all pending regulations will be on hold. A shutdown could also potentially delay Mr. Zeldin’s plans for repealing dozens of climate protections enacted under the Biden administration.