A staple feel-good win that served as a hallmark of Massachusetts’s commitment to environmental causes has suffered from a decades-long slow but decisive downward spiral.

The state’s bottle deposit program, which has handed out a nickel for each eligible bottle and can that consumers redeem since it started in 1983, has been hailed as a game-changer in reducing litter and incentivizing recycling.

But the program’s success has deteriorated steadily over time.

In fiscal year 1995, 87 percent of eligible bottles and cans bought in the Bay State were redeemed. Ten years later, the redemption rate dropped to two-thirds. Last fiscal year, just one-third of the bottles and cans sold in Massachusetts that could be returned were brought back for redemption, according to data from the state Department of Environmental Protection.

Out of the 10 states that have a “bottle bill,” including neighboring New York, Vermont, and Connecticut, Massachusetts has the lowest redemption rate.

“It’s a distinction with dishonor,” said Janet Domenitz, executive director of MASSPIRG, a public interest group and longtime proponent of the program. “And it’s so obvious how we could improve instantly.”

For advocates, it’s a clear sign of the obvious: A nickel just isn’t what it used to be more than 40 years ago, leading more people to forego the chore of redeeming containers. They are making a push for legislative reforms that would double the refund rate from 5 to 10 cents and expand the list of bottles and cans that can be redeemed.

Past efforts have stalled — clearing the Senate as recently as 2024, only to peter out in the House — but this time, advocates are taking a new tack: targeting Polar Beverages, the popular Worcester-based company that opposes bottle bill expansion.