In retail stores of the global fast-fashion brand H&M, customers can bring in their no-longer-trendy or otherwise unwanted clothes and get a discount on new purchases. The chain has collected more than 30,000 metric tons of garments since 2013.

The goal of the H&M program is to prevent used clothes from going to landfills and incinerators and instead give them new life in second hand stores, as cleaning rags, or as fiber material in insulation products.

But H&M has bigger plans. It hopes to use end-of-life clothes as raw material for making new fashions.

By analyzing the environmental life cycle of clothes manufacturing, brands such as H&M and Levi’s have learned that a large proportion of the water use and carbon emissions associated with their industry happens during the production of fibers such as cotton and polyester.

“We want to find a solution for reusing and recycling all textile fiber for new use,” says H&M spokesperson Ulrica Bogh-Lind. “This can change the way fashion is made and massively reduce the need for extracting virgin resources from our planet.”

Achieving this so-called circular economy goal is many years off and will require significant technological innovation, Bogh-Lind concedes. “New technical solutions are important for our ambition to close the loop.”

But industry critics argue that these long-term ambitions obscure environmental shortcomings in the ways apparel is produced today at contract manufacturing sites around the world. They would like to see sustainability efforts focus on areas where impacts are big and immediate—even if the solutions aren’t as stylish as designing a line of eco-friendly clothing.

The apparel industry has been on a years-long odyssey to account for its impact on the environment. This year H&M published its 14th annual sustainability report. Yet companies often learn about poor pollution controls at far-flung manufacturing sites at the same time as government agencies, investors, environmental organizations, and customers.

Apparel companies find themselves in this fix for a number of reasons. Their supply chains are long, and they do not manage—or even know about—day-to-day operations in faraway factories. In addition, developing countries often do not have adequate laws, enforcement, or infrastructure to control and treat pollution.

To address these gaps, leading brands are starting to take a closer look at water consumption, pollution, energy use, and chemical inputs across their supply chains. They hope to gain transparency, apply sustainability guidelines, tighten responsibilities, and enforce consequences.

The industry’s heavy use of water is a major priority. Textile manufacturing is responsible for more than 11% of wastewater discharged in China, where about half the world’s garments are made. In 2012, that amounted to 2.4 billion metric tons, according to the International Water Association.

Fabric finishing chemicals that can end up in waterways include bleaches, surfactants, solvents, acids, alkalis, dyes and inks, resins, salts, organic and inorganic stabilizers, softeners, and fluorocarbons used in stain- and water-resistant coatings.

Data compiled in 2014 by the Institute of Public & Environmental Affairs (IPE), a China-based nongovernmental organization, showed that more than 6,000 wastewater compliance violations could be traced to textile and clothing manufacturers. Some critics say that not nearly enough is being done at those sites—or at brand headquarters—to find and correct pollution problems.

“It would be very fair to say that the goals for this industry at this point would be to reach the U.S.’s 1975 levels of environmental control in the countries where they manufacture their products today,” says Linda Greer, a senior scientist at the Natural Resources Defense Council. “It’s amazing that companies that have a reputation to protect are working like this.”

Greer first visited garment factories in China in 2007 and was shocked to discover the magnitude of the pollution they create. She was inspired to create the NRDC program Clean by Design to advocate that textile mills follow certain best practices to cut the use of water, energy, and chemicals.

Recently, Greer worked with IPE on the 2015 Corporate Information Transparency Index, a system to evaluate brands’ green supply-chain practices. They analyzed public data on 53 clothing brands and their supplier relationships.

The index allots points for companies that respond to questions about their operations, screen suppliers for pollution violations, require compliance and take corrective action with suppliers, extend green supply chain practices, disclose data on CO₂ and pollution emissions, establish recycling programs, and track used products.

Among the problems IPE identified is that many industrial enterprises in China have instituted centralized treatment for wastewater, but those treatment plants do not meet environmental standards. These treatment plants have instead become “centralized pollution sources,” a report accompanying the index alleges, and the majority of brands are not on track to resolve what IPE considers a loophole.

The index gave top rankings to Adidas, H&M, Levi’s, Marks & Spencer, Walmart, and Nike. But with scores for these firms ranging from 49.5 to 66.0 out of a possible 100, the index found plenty of room for improvement. For example, no company got more than half of the possible points for the category “Identify and manage main polluting sectors.”

Levi’s has been working on requirements for its suppliers since the mid-1990s, instituting water quality standards based on Environmental Protection Agency regulations for limits on color, including dyes, and organic pollutants as estimated by chemical oxygen demand and biological oxygen demand, says Michael Kobori, the firm’s vice president for sustainability.

“That got our vendors thinking about chemistry. Then in 2002, we issued our first restricted substances list—those are all the chemicals we do not want used in our products,” Kobori says. The list includes pesticides, herbicides, azo dyes, and solvents that are not allowed under regulatory frameworks including Europe’s Registration, Evaluation, Authorisation & Restriction of Chemicals (REACH) and those instituted by the California Department of Toxic Substances Control.

Given that Levi’s has well over 500 suppliers in Mexico, China, Pakistan, Haiti, Egypt, Poland, Turkey, and Bangladesh, “it’s not always easy to understand exactly what goes into the formulation of chemicals you are using,” Kobori admits. “It can be challenging to get visibility into our complicated supply chain, and some vendors want to maintain intellectual property protection for their products.”

Individual brands say they don’t have much sway over the operations of their suppliers, which have many other customers, Greer points out. Apparel companies often don’t buy more than 20% of a fabric manufacturer’s output, and 10% is common. But Greer claims that’s by design. “They don’t want any level of business responsibility for the operations of the factory.”

But when brands work together, Greer says, they can achieve much more. Both Greer and Kobori are on the board of the Sustainable Apparel Coalition (SAC), a group of companies that represent about 40% of the global textile market.

“SAC is a real process for gaining critical mass,” Greer says. “It represents important buyers and could even be 100% of buyers at a lot of mills. If they are aspiring to be more responsible and can have the same set of demands, then that’s where we’ve got to go.”

The coalition has been working for five years on a set of tools called the Higg Index. The tools allow a company to measure and track the environmental, social, and labor performance of its operations. Users can receive scores for individual categories and benchmark against other SAC members.

The Higg is not a set of standards to follow, and there are no pass-fail criteria, points out Jason Kibbey, SAC’s chief executive officer. “From a low level of performance to a high level of innovation, it is more a report card.” SAC members are not, at this point, required to use the tools.

Greer would like to see companies use the tools not only to get a picture of their environmental impacts but also to stop doing business with manufacturers that are not high performers. She complains that H&M—a high-ranking company—tracks which manufacturers have violations, as reported by IPE, “but never does anything about anything they find.”

Kibbey says SAC is prepared to evolve. “Down the road, what we’ve begun discussing is that member companies will have to have a reasonable engagement with our tools and ultimately be in a place where every company is improving,” he says. “It’s a delicate balance—you want to create tools that encourage positive behavior but not create a sustainable cartel.”

Levi’s Kobori says his goal is not just to tell suppliers what chemicals they cannot use but to arrive at a list of best-in-class chemistries for new products and to develop innovative materials and textile technologies. To get there, the company must first learn about all the chemicals that end up in its products and evaluate them on the basis of relative hazards.

A comprehensive screening approach “creates a clear and common metric for saying ‘What is the chemical footprint for that product, based on chemicals of high concern?’ ” says Mark Rossi, executive director of the advocacy group Clean Production Action.

CPA is developing a new standard to help companies evaluate their chemical management practices and compare them with industry leaders. This year, Levi’s participated in the organization’s first-ever Chemical Footprint Project report.

Rossi suggests that brands will find their products contain substances likely to be regulated in the future. “That’s where the power of alternatives assessment comes in, where you really want to do the deep dive and evaluate the alternatives.” For example, the apparel industry is looking for alternatives to solvents such as toluene and N,N-dimethylformamide as well as short-chain fluorinated polymers used to repel stains and water.

Levi’s has developed its own process to ensure the ingredients used in new products have been screened for chemicals of high concern. In the firm’s design department and its Eureka Innovation Lab, “every product—every new look or finish on the jean—is developed now only with chemicals that have gone through our screened chemistry framework,” Kobori says.

Another innovation that has earned Levi’s plaudits from sustainability experts is its Water<Less jeans process, which omits water in the stone-wash process and combines multiple finishing and washing steps. The company estimates the changes cut water use by up to 96% for some styles. It plans to expand the process to cover 80% of its manufacturing by 2020.

For its part, SAC is working to make the Higg tools more widely available. One area it can assist is in finding a way to recycle the garments being brought back to H&M and other stores. For now, however, high costs, technology limitations, and constrained sourcing have confined brands to using recycled fibers in limited quantities or in small-edition, eco-friendly lines.

“When it comes to circularity, there are still a lot of scale issues to create products that can be recycled to the same product over and over again,” SAC’s Kibbey explains. “A lot of companies are seeing this as a longer-term investment. It is happening—but not at a large enough scale to be competitive.”

For example, the Japanese chemical firm Teijin saw an opportunity to sell polyester recycled from fabric back to apparel makers. In 2012, it formed a joint venture with China’s Jinggong to build a facility that recycles polyester through a process of depolymerization and repolymerization.

Last month, however, Teijin reported that it would take a $50 million loss on the business because of low crude oil prices and volatile prices for virgin polyester.

Meanwhile, efforts are under way to increase the percentage of recycled cotton that can be incorporated into new garments. “When you recycle and reuse cotton, the fiber naturally gets shorter and results in a product that is not as strong as those made with virgin fiber,” Kobori explains.

Levi’s is working with the start-up Evrnu on a technology that breaks down cotton fibers into a semiliquid pulp. The cellulose-containing pulp is extruded through a spinneret—a device similar to a showerhead. The size, number, and shape of the holes determine the characteristics of the fiber. “The mind-blowing thing is we can create fiber with the characteristics of premium cotton—it is a higher quality fiber than when it was new,” says Stacy Flynn, cofounder of Evrnu.

Similarly, H&M and the sports brand Puma have partnered with the English. firm Worn Again, which is working to scale up its lab-based processes to recycle polyester and cotton textiles. Although the company won’t detail its technology, its chief scientific officer, chemist Adam Walker, is an expert on ionic liquids, which can be used to dissolve fibers such as cellulose.

Adidas has even dipped its toe into recycled nylon—specifically nylon reclaimed from confiscated gill nets from illegal fishing operations. Last year, it created a concept shoe made with the nylon, which first had to be cleaned of its fishy smell, then powdered and re-extruded. The shoe also contained polyester from recycled soda bottles.

Without a way to cost-effectively recycle textile fibers, it is unclear what the business case is behind take-back schemes at stores such as H&M, cautions Martin Reeves, a managing director at Boston Consulting Group. Reeves studies whether—and how—corporations create value with their sustainability initiatives.

“A take-back program is a great example of the difference between an issue and a strategy,” Reeves observes. “Waste is an issue; taking the waste back is an action, but it is not a strategy that creates an advantage.” Getting to that point will require investment in process innovation, changes to how the supply chain works, and enough scale to make the new way economic, he says.

Those efforts could eventually create considerable value, Reeves adds. Consumers may be willing to pay more. Companies can build their reputation and attract new customers by differentiating themselves from their competitors.

And NRDC’s Greer points to the other side of the coin, arguing that there is value in eliminating practices that create reputational risk. “Companies these days are striving to have a different sort of relationship with their consumer. Think about all the commentary around the food industry,” she says.

“How easy is it to imagine that a celebrity tweets that she sees a brand company has a big bad factory in China and won’t buy there until they fix it?” Greer asks. “That’s when all those great corporate responsibility plans go right down the toilet.”