Microbeads, the tiny plastic beads used in some facial scrubs and toothpaste that rinse down drains and pollute oceans and lakes, are now banned in “rinse-off” products in the U.S. But it’s not like those products are great for the environment now: you’re probably still slathering other lesser-known petrochemical ingredients on your face, like methylparaben and propylene glycol. One company wants to replace those ingredients–along with plastics used in other everyday products–with silk.

“To a very large extent, the majority of our skincare products, our deodorants, and shampoos, are filled with micro- and nano-plastics,” Greg Altman, co-founder of Silk Therapeutics, a new company working on a more natural solution. “They’re not just the microbeads that you think of for facial scrubs and things of that nature, but they are plastics at such a small size that when you apply them to the skin you can’t even see them. They’re used to basically fill the jar. They’re used as emulsifiers. They’re used as stabilizing agents for other active ingredients.”

Like microbeads, those ingredients can end up in waterways. “The big issue with man-made plastic ingredients in cosmetics is that generally very little thought has gone into the complete lifecycle of the product,” says David Andrews, a senior scientist at the Environmental Working Group, a nonprofit that researches health and environmental issues in consumer products. The ingredients are also made from fossil fuels and are a contributor to climate change.

There are alternatives, however: Silk, for instance, is made by silkworms that eat organically grown mulberry leaves, a process that removes CO2 from the air. While most silkworm cocoons are used for making fabric, Silk Therapeutics uses the protein from discarded silkworm cocoons to make “liquid silk.” Because it doesn’t need the same high-quality cocoons that would be used in fabric, the company can use cocoons that would otherwise be wasted; the silkworm can also survive, unlike the case in most silk-making, in which the cocoon is boiled to get the fiber. By controlling the process of making the liquid silk, the company can create silk molecules in different sizes to perform different functions.

This new silk can take the place of synthetic ingredients that previously served to stabilize or protect a product. Many plastic-based ingredients may not even show up on labels, Altman says. Plasticizers used to make a polymer may be embedded inside that plastic, and not disclosed. Other ingredients called incidentals–ingredients to make an ingredient–also aren’t disclosed.

“Both the plastics and the plasticizers get into our bodies, they get into our ecosystems, they get into our oceans, they get into our food supply,” he says. “That hidden use of plastic is what we’re deeply passionate about trying to replace with silk.”

At the moment, the silk polymers are more expensive than their fossil fuel equivalents, and the company’s line of skincare is “premium,” which in this case means “prohibitively expensive.” One 1.7 ounce bottle of moisturizer costs $95. But the cost of the liquid silk will come down as production scales, and the company wants to make products that all consumers can afford. In another application–in the apparel industry–the liquid silk is already competitive with fossil-fuel-based materials.