Call it the H&M effect, or fast fashion.

Americans are buying, and discarding, clothes more quickly than ever. On average, each of us throws 54 pounds of clothes and shoes into the trash each year. That adds up to about 9 million tons of shoes, jackets and other wearables that are sent into the waste stream, according to the U.S. Environmental Protection Agency.

Traditionally, the options for dealing with that waste have started with an R: Reduce, re-use or recycle. But a clutch of designers are pursuing a different tack. They're producing clothing and accessories that are biodegradable — or at the very least, have parts that are capable of decomposing into natural substances. The movement is still in its infancy, but it's an important development in an industry that's increasingly scrutinized for its wastefulness.

Gucci began selling sunglasses and footwear made with biodegradable plastics over the summer. Last fall, Stella McCartney debuted several styles of heels with mock croc and faux leather uppers anchored with chunky, biodegradable rubber soles. And in the near future, Puma says, it will produce a new line of T-shirts and sneakers that can be ripped up and buried in the ground as fertilizer.

"Everyone is beginning to appreciate the need to reduce fashion's impact on the environment," said Alex McIntosh, business and research manager for the Centre for Sustainable Fashion at the London College of Fashion. "Compostability is part of a wider waste management agenda" that is likely to grow in coming years, even if its use is only beginning in the $774 billion global apparel manufacturing business.

Of course, it's unlikely that anyone who invests $500 in a pair of designer shoes or glasses would throw them in the trash and even less likely that such a rarefied buyer would toss a luxury item onto a compost pile. But "it's great that high-end designers are exploring these ideas, as their influence has an impact on the collective psyche of the design community," McIntosh said.

That's certainly the case with Stella McCartney, the well-known vegetarian designer whose shunning of leather and fur created more acceptance of synthetic alternatives in high fashion. McCartney is often credited with turning faux furs and leather handbags into a fashion "do" when such materials had long been considered too down-market. Now designers including Calvin Klein and Michael Kors regularly work imitation furs into their designs. And the idea has trickled down to mass retailers such as H&M and Forever 21, where most of the "leather" goods are, in fact, pleather.

Compost your Gucci

McCartney's partially biodegradable pumps, which feature 4-inch heels and thick white soles reminiscent of gym sneakers, went on sale last September. Only the soles, made from plant-derived plastic, are biodegradable. But their inclusion reflects McCartney's philosophy that "doing a little something is really a lot better than doing a lot of nothing."

Gucci began incorporating more castor oil seed plastic into its sunglasses in 2011. This year, the company introduced sunglasses made with biodegradable frames and plant-derived, bio-plastic ballerina flats and sneakers.

Like Stella McCartney's pumps, though, Gucci's Liquid Wood sunglasses and California Green sneakers aren't entirely biodegradable. They're made from a mix of materials. Only the soles of the low- and high-top men's sneakers are made from plant-based plastics that decompose over time without leaving chemicals or other harmful substances behind. As for the sunglasses, the frames are made from wood fiber and natural wax. The metal joints are constructed with recycled metal, which points to the difficulties of making items that will entirely decompose. Only 100 percent natural fashions, such as cotton T-shirts stitched with cotton thread, can easily, and completely, break down in combination with heat, moisture and time.

"With textiles, you get monstrous hybrids," said Susanna Schick, owner of Sustainable Fashion L.A., an environmental consulting firm. "Having spandex in something makes it much easier to wear, but if you put spandex in cotton, it's a petroleum-based fiber with an organic fiber, so the cotton will decompose but the spandex won't. It's a difficult situation."

And it's one that isn't likely to go away.

"When it comes to fashion, we need to design products that can either go safely back into the biosphere, meaning they would be compostable, or safely become technical nutrients, such as polymers, metals and polyester, that can be recycled into new products," said Lewis Perkins, of the Cradle to Cradle Products Innovation Institute in San Francisco.

While biodegradability is a step in the right direction, Perkins said the more important development in sustainability in fashion is using more technical fibers such as polymers that can be recycled (or continuously used) since fashions made from natural materials are so water- and energy-intensive.

Almost 13 million tons of textile waste are generated annually, according to the EPA. Of that, just 14 percent of the textiles used in clothing and footwear is recovered for re-use or recycling. Still, more designers are seeing its potential — and not only at the high end.

L.A. designer Linda Loudermilk made a splash in 2010 with a compostable bikini that can completely decompose in 180 days.