Fourteen-year-old Kalpona Akter sat hunched over a sewing machine in a noisy clothing factory in Bangladesh. She was making a pink tank top—the 83rd one she’d stitched in the last hour. Suddenly, Kalpona heard a man shout, “The top floor is on fire!” People panicked as they rushed to escape the burning building.

Fortunately, everyone—including Kalpona—made it out alive. Since then, several clothing factories in Bangladesh have suffered much more devastating accidents. The worst occurred in 2013, when the Rana Plaza building collapsed, killing more than 1,100 people and injuring another 2,500. It was the worst accident in the history of the garment industry. The tragedy brought to light the terrible working conditions in developing countries—where most clothing sold in the U.S. is made.

Unsafe buildings, child labor, long hours, and low wages are only some of the issues affecting garment workers. Making clothes also requires the use of hundreds of potentially hazardous chemicals, from dyes to detergents. They pose a risk to people and the environment.

“There’s a heightened awareness about fashion’s human-rights and environmental toll,” says Elizabeth Cline, author of the book Overdressed: The Shockingly High Cost of Cheap Fashion. “[Today’s] consumers want to know more about where their clothing is coming from, how it’s made, and its impacts.”

Fashion has become a trillion-dollar global industry. Over the years, many clothing companies have outsourced the manufacture of their goods to Bangladesh, India, China, and elsewhere (see Where Your Clothes Come From). Workers in these places earn a fraction of what U.S. workers make (just $2 a day in Bangladesh). That means lower prices for shoppers and higher profits for retailers. As a result, Americans’ expectation for cheap fashion has skyrocketed.

To meet demand, entire towns in developing countries have transformed into clothing-making hubs. One example is Tirupur, India, or “Knit City.” Companies there export billions of dollars worth of clothes each year and employ half a million people. If your clothing has a “Made in India” tag, it likely came from Tirupur.

Before a textile boom in the 1990s, rice paddies, coconut palms, and banana trees thrived around Knit City. But polluted wastewater dumped into Tirupur’s rivers by its more than 700 textile-dying facilities has left the landscape parched and barren. Although laws now prohibit the practice, they aren’t well-enforced. Many businesses still illegally discharge wastes into rivers, which often are colored with dye.

The garment industry has the largest impact on the environment in terms of pollution after the oil industry. It’s also the second-largest water polluter after agriculture. 

Just making one pair of jeans requires, on average, 7,000 liters (1,850 gallons) of water to dye, bleach, and wash them to achieve a worn-in look. If wastewater from the process is not treated to remove chemicals onsite, it ends up in the environment. That’s a big problem in places like China, where in some industrial areas the water is so polluted it’s sickening people.

Scientists have detected chemicals used to make clothes lurking in waterways near textile factories in Thailand, Mexico, and Indonesia as well. They’ve found substances such as nonylphenols (NPs), byproducts of chemicals in detergents, and perfluorinated chemicals (PFCs), used to make clothes stain- and water-resistant. Both classes of chemicals can disrupt hormones—chemical messengers that control certain body functions. NPs are known to cause reproductive and developmental problems in aquatic animals, like fish. They, along with PFCs, have also been detected in people. But how much they impact human health is unclear.

These pollutants can also bioaccumulate, or build up inside organisms. Even worse, they stick around for an extremely long time in nature. PFCs, for example, “are incredibly resistant to breakdown, so they essentially last in the environment forever,” says Arlene Blum, a chemist and executive director of the Green Science Policy Institute in Berkeley, California.

Some clothing-producing countries are requiring textile mills to treat and reuse wastewater so that none is discharged into the environment. Countries in the European Union that import clothes are now restricting the amounts of certain chemicals garments can contain. Many brands are also starting to take more responsibility for how they source their products.

The industry is making progress, but there’s still a long way to go. “It’s a step in the right direction,” says Cline. “The industry seems like it’s figuring out how to make fashion that’s good for people and the planet.”