In a tight retail environment, apparel brands have a vested interest in understanding consumers’ eco concerns, and how fabric choice could impact their business.

According to the Cotton Incorporated Lifestyle Monitor Survey, most consumers want to do right by Mother Earth. The majority (64%) say they always or usually recycle, use refillable bottles (55%) and purchase energy-saving appliances (53%) in an effort to protect the environment. But just 16% check corporate environmental policies before making a purchase.

However, companies shouldn’t take that to mean shoppers don’t care.

“Many people, even those in the apparel business, have no idea the rayon they’re using might be coming from a tropical rainforest,” says Brihannala Morgan, senior forest campaigner with the Rainforest Action Network (RAN). RAN created the Out of Fashion campaign to demand the fashion industry commits to “getting rainforest destruction and human rights abuses out of our clothing.”

As a natural fiber, cotton is biodegradable. The Environmental Protection Agency’s Julia Valentine, spokesperson, explains how clothes made of a synthetic fabric like polyester and nylon can end up as microplastic in lakes, rivers and, ultimately, the world’s oceans.

“Synthetic fabrics are made partly or wholly from plastic polymers. In addition to the fact that these polymers are made from petroleum, synthetic fabrics may also degrade or break down during everyday use and laundering to produce synthetic microfibers,” Valentine says, explaining that microfibers are those less than 5 millimeters in size in any dimension. “These microfibers do not biodegrade in the environment like natural fibers do. Worldwide monitoring is showing that microplastics exist in all of the world’s oceans and may pose health and ecological hazards.”

After being educated about deforestation and microfiber waste issues, 66% of consumers say they’re bothered that brands and retailers are using synthetic fibers in their apparel, according to Monitor data.

Of all the fiber-related issues, deforestation to create rayon fibers (31%) is the most concerning to consumers, followed by microfiber waste from synthetics filling up the world’s oceans (25%).

Morgan explains that most of the wood pulp for synthetics comes from rainforests in four countries: Indonesia, Brazil, Canada, and South Africa. But the area most conflicted is Indonesia.

“Companies that produce viscose staple fiber rely on fast-growing trees like eucalyptus and acacia,” Morgan says. “They grow the fastest in tropical regions.”

Indonesia is home to the Leuser Ecosystem. The Leuser is filled with carbon-rich peatlands. RAN states that when these areas are drained and clear cut, and the peat is exposed to air, it begins to oxidize. This releases large amounts of carbon dioxide emissions into the atmosphere, a process that continues for decades.

The dried peat is also highly flammable, and last year “killer haze” from peatland wildfires was responsible for 90,000 early deaths, according to researchers from Harvard and Columbia.

After being educated about the microfiber waste issue, 3 of 5 consumers (60%) say they are likely to check the fiber content label before purchasing clothing to avoid synthetics, according to Monitor data.

Even before learning about the environmental issues with synthetics, 73% of consumers say better quality garments are made from all natural fibers like cotton, and 65% are willing to pay more for natural fibers.

What’s more, 63% are very or somewhat likely to say they would “feel more connected or loyal” to a brand that offers clothes made of natural fibers, followed by those that offer sustainable apparel.

“We hear from consumers every day,” RAN’s Morgan says. “We have a large list of people who self-identify as caring about diversity, climate rights, deforestation. And when we told them of the connection between rayon and deforestation, we had hundreds of thousands taking part in our campaign saying they didn’t want companies they bought clothes from involved in it.”