WASHINGTON — The Obama administration is preparing to introduce major steps to phase out production of a popular chemical coolant used in refrigerators and air conditioners, citing growing evidence that the substance is contributing to the warming of the planet.

The White House will announce Tuesday a series of voluntary commitments by some of the country’s largest chemical firms and retailers to move rapidly away from R-134a and similar compounds used in nearly every office, home and automobile in the country, according to current and former U.S. officials familiar with the effort.

The administration is simultaneously stepping up diplomatic efforts to encourage major U.S. trading partners to phase out production of the potent greenhouse gas, the officials said. The initiatives are being disclosed in advance of next week’s summit of world leaders at the United Nations to debate options for slowing the buildup of heat-trapping gases in the atmosphere.

The class of chemicals to which R-134a belongs – called hydrofluorocarbons, or HFCs – became popular as a replacement for Freon, the refrigerant banned since the 1990s for damaging the Earth’s ozone layer. Most HFCs are harmless to ozone, but collectively they have become a significant driver of climate change – some are up to 10,000 times as potent per ounce as carbon dioxide, climate scientists say.

The steps unveiled this week are intended to accelerate the phaseout of most types of HFCs while still allowing manufacturers time to shift to more environmentally friendly replacements. If fully implemented, the measures would have an impact equivalent to removing 15 million cars from the nation’s highways for a decade, according to an administration official familiar with the plan.