Gov. Madeleine Kunin wants Vermont to become the first state to ban all disposable diapers, but her plan is being trashed by some, including day-care operators who want no part of a mountain of cloth.

"The time has come to be responsible and to find the way to say yes - yes to required statewide recycling, to bans on certain polluting products, to changes in lifestyle," Kunin said in her state of the state speech last week.Only Nebraska has banned disposable diapers, but it allows the sale of diapers that are biodegradable, even though such products aren't believed to break down in the depths of oxygen-starved dumps.

Kunin, whose proposal would ban disposable diapers by 1993, noted that while the usable life of a disposable diaper may be a few hours, they won't decompose in dumps for hundreds of years - or several generations of babies later.

Environmental groups have quickly supported the plan by Kunin, who last year made the state the first to ban the sale of vehicles that use ozone-depleting chemicals in their air conditioning. That ban starts with 1993 models.

"They are a large part of the waste stream," said Ned Farquhar of the Vermont Natural Resources Council. "The throw-away society is wasting energy and materials, not just with diapers, but with a lot of similar products. We need to ban things to keep people from using them."

The piles of discarded diapers make up about 2 percent of the nation's waste, and about 85 percent of all parents use disposable diapers exclusively, according to industry estimates.

Vermont officials estimate that 43.5 million disposable diapers end up in the state's dumps every year.

Opponents of a ban argue that the governor's plan won't have much impact in solving the state's mounting garbage disposal problem. Representatives of the health and day-care industries also say they are not ready to handle such a ban.

"There has been a tendency to pass into law programs on the basis of trendy catchwords, rather than science or careful consideration of all the different issues," said William Gilbert, a lobbyist representing the American Paper Institute.

Gilbert said that mandating cloth diapers would add two to three more loads of hot-water washings weekly for families with babies, raising its own questions about environmental damage.

Day-care centers, especially in rural parts of the state where there are no cloth diaper services, fear how they would be affected.

"If a ban went into effect today, it would create real havoc," said Lea Hatch, a day-care regulator for the state. But she added that centers in areas with access to diaper services already are beginning to offer that option to parents in lieu of disposables.