A 548-page Senate bill to put the chill on global warming would carry a multibillion-dollar price tag for U.S. corporations. But a tiny provision buried deep within the measure could wipe out an obscure industry sector and render the days of cheap, do-it-yourself air conditioning repairs a relic of the past.

That has lobbyists working to ice the provision from the bill altogether.

The policy, which they call the “can ban,” would outlaw the sale of small containers of the automobile air conditioning refrigerant known as R-134a, a hydrofluorocarbon. Such cans are widely available at auto parts stores, such as Auto Zone, for less than $20 a pop.

Advocates for companies that package the chemicals in the small containers say the bill, sponsored by Sens. Joe Lieberman (ID-Conn.) and John Warner (R-Va.), not only would shutter their industry, but would have a disproportionately negative impact on low-income people who typically can’t afford the $100-plus bill at an auto repair shop to have their cars’ air conditioners serviced.

The ban would not apply to containers that hold 20 or more pounds of the exact same coolant that is used by professional mechanics.

“This provision has very adverse unintended consequences for a significant part of the population, while at the same time, it will have a minimal at best impact on global warming,” said Jim Dornan, a senior vice president at the lobbying shop Artemis Strategies, which has been retained by the Automotive Aftermarket Industry Association to work the issue.

What’s more, industry lobbyists say they have run into widespread confusion on Capitol Hill about the can ban. Some Senate aides mistakenly believe the provision, located on p. 534 of the massive bill, isn’t even in the legislation.

“This is such a small aspect of the bill that people aren’t focusing on it,” said Aaron Lowe, the AAIA’s vice president for government affairs. “People are focusing on huge issues, but this issue is going to impact a lot of people directly, and we think unfairly.”

He added, “We got involved because the impact would fall on people who couldn’t afford to have their cars fixed by somebody else.”

A Senate aide familiar with the bill said the policy motivations behind the provision are designed to keep unnecessary amounts of the chemical from leaking into the atmosphere, contributing to global warming.

But the aide added that the argument about the impact it could have on lower-income people is “a good point.”

“We’re listening to them,” the aide added. “We’ve heard the concern. We don’t think it’s presented in bad faith, and we think we have an obligation to at least listen.”

Doug Wheeler, a partner Hogan & Hartson, represents the Automotive Refrigerant Products Institute, whose members say they could go out of business if the Lieberman-Warner Climate Security Act should pass.

Already, he said, the industry is expecting a new generation of car air conditioning refrigerant to take over — one that has less global warming impact. But, he said, the companies that package R-134a can’t switch to the new product immediately.

“They need some time in which to make the transition,” Wheeler said. “We’re looking for a way that effects that transition that doesn’t put the industry out of business and deprive do-it-yourselfers access to a low-cost refrigerant.”

Wheeler concedes that the R-134a chemical contributes to global warming. Gases are rated for their “global warming potential” by how they compare to a baseline measurement of carbon dioxide, which has a rating of 1, he explained. R-134a has a rating of 1,300, he said.

David Doniger, climate center policy director at the Natural Resources Defense Council, which supports the provision, said that giving the companies more time to transition would amount to going down the wrong path.

“What they seem to be saying is, ‘Let us keep selling the can until somebody someday ends up getting around to transition this compound to another compound,’” Doniger said. “We’re saying the better answer is to stop the use of these cans and get the car air conditioners fixed.”

Banning the small cans, Doniger said, “is an easy way to reduce the damage” to the environment.

He added that the small cans sold to do-it-yourself mechanics contribute to global warming because these individuals often are using the chemical to refill a broken air conditioner that will simply continue to leak.

“So it’s basically an indirect form of pumping this stuff in the air,” he said. “The need is to get these air conditioners serviced and fixed when they leak.”

Doniger added that repair shops have more environmentally friendly disposal methods. Professional mechanics are required to suck out any remaining chemical into a machine, whereas do-it-yourselfers simply toss the cans into the trash, which means some of the chemical is absorbed into the atmosphere.

“People are swept up in this understandable concern about greenhouse gases,” Wheeler said. “But then there are these unintended consequences. It is much more expensive to go to the auto repair shop.”

Doniger contended that there are other measures in the overall Lieberman-Warner legislation that would help ease any added burdens on lower-income people. “Let’s look for a solution to it there, rather than continue this bad practice,” he said.

Bill Quest, the former owner and now a consultant for EF Products in Dallas, said scientists for companies like Honeywell and DuPont are busy looking for the next generation of refrigerant that will contribute less to global warming than R-134a, which EF Products currently packages.

Quest said the transition is not far off and that Europe will require new cars after 2011 to use a coolant that has a rating less than 150 on the “global warming potential” scale.

He added that the can ban would ultimately be a boon to the professional auto-repair industry, which he said would stand to bring in more than $2.7 billion of profits each year. “Right now it costs someone to recharge their air conditioner about $13.32. If you went to a service [station], the cost would be $156.81,” he said.

“It seems ironic that one of the first measures people are looking at on global warming would take car air conditioning away from low-income individuals,” Quest added.