The adage says, “You are what you eat.” But what about what you wear? With countless chemicals and substances involved in clothing production, many consumers are left wondering what they are putting against their skin.

From mill to designer, the supply chain is aware of the concern. In February, global leaders in the textile chemical industry accepted the invitation of House of Denim, a non-profit foundation in Amsterdam, to discuss collaboration with the goal of including all players operating in textile chemistry to drive towards consistent and conscious chemistry throughout the denim supply chain and beyond.

“Amsterdam is home to some of the world’s leading jeans brands, but we are fully aware that to clean up this industry, we need to collaborate across borders and involve players from the various stages of denim: this is a complex global industry,” said James Veenhoff, House of Denim founder, in a press release. “Although there’s a lot of hard work ahead, it’s exciting to see industry visionaries from as far apart as India, China, Europe and the Americas so unanimous in their support for this direction. We need our leaders to lead—and it appears that this is what is happening, starting from the world of chemistry.”

The debate and confusion surrounding the use of chemicals in denim manufacturing came to a head at Kingpins Transformers last October, where representatives from the supply chain squabbled about the best safe, sustainable and affordable practices.

“Public opinion and concerns over the environment and safety have done a solid job at ‘shocking’ big brands into action. But to be honest, the chemical side of things is so complex that no company or brand is able to influence things on their own,” said Transformers initiator Andrew Olah. “That’s why this collaboration is so essential for real change to happen.”

The chemicals and substances used to achieve looks in the denim industry go through careful inspection to make sure that the products leave out unnecessary and potentially harmful substances. The two lists at the center of the textile industry’s battle to exclude harmful chemicals are the Restricted Substance Lists (RSL) and Manufactured Restricted Substance Lists (MRSL). Each brand creates their own guidelines. However, many lists contain the same substances due to government regulation and/or legislation that limits certain hazardous chemicals.

The difference between the two lists seem minor, but exists.

As Garmon Chemicals CMO Alberto De Conti explained, the MRSL includes chemicals and substances created from treatments in manufacturing. As in, potential substances formed from heat and chemical reactions. These substances might not appear in the final product, but might be created as byproducts of chemical reactions, and therefore must be accounted for during the process for the MRSL.

RSL serves as a list of chemicals and substances that are not in the final product. The difference lies in the point of production.

Government regulations and laws aside, each brand typically claims their own RSL and/or MRSL. As chemists conduct more research, the lists grow.

The Environmental Protection Agency (EPA) told Rivet, “[The] EPA will consider chemicals already on the market as the Agency identifies priorities for risk evaluation,” meaning the lists constantly change.

Take Nike for example. The brand’s website states: “Our Restricted Substance List is based on the most stringent worldwide legislation or regulation. In addition, we’ve voluntarily included substances that may not be legislated but have been identified as hazardous to the worker, consumer or the environment.”

Those in the denim industry understand the limitations—creatively and financially—to achieving certain finishes without banned items on the RSL and MRSL.

“It is fairly costly to put together a list,” De Conti said. “Now, quite frankly, if you’re a new brand…[the RSL] are available online. So, it depends on what you want to do. What is extremely costly is to be compliant with these lists,” he added.

De Conti urged the necessity of having one list for all brands to follow.

“What we really need is one guideline that is come up for everybody that we can test all of our products against that guideline. Because, if today [someone asks for a] chemical product to be tested for formaldehyde, then [the] competitor comes along and wants that specific chemical to be tested in a slightly different way, we’ll do it again,” said De Conti. “It’s twice the cost and you get to exactly the same result.”

Chemical company Archroma sees changes in guidelines as well.

“[The] denim industry is going through continuous challenges regarding sustainability,” said Miguel Sanchez, Archroma head global business development—denim and casualwear. “The use of hazardous chemicals like Sodium Hypochlorite or Potassium Permanganate for the bleaching effects, or the sand blasting for the worn out looks, are some examples of problems to be solved for a safer and better production of denim articles.”

While those in the textile industry take sustainability seriously, the industry saw many changes and an uptick in possible harmful chemicals over the years.

“People love scandals and disasters in our industry and I’ve seen many people thrown under the bus for nothing,” quipped Alberto Candiani, global manager of Candiani Denim.

A big factor in a safe and clean environment comes from RSL and MRSL, ensuring that mills and tanneries avoid potentially harmful chemicals and substances.

Candiani grew up on his family’s mill compound located in Parco Del Ticino, 30 miles outside of Milan, Italy.

“The environment itself has forced us to perform differently and invest way more money than any other mill in the world in new sustainable technologies and eco-friendly solutions,” said Candiani. “My bedroom at my parent’s house was facing the finishing division. We would have not lived there for over 50 years if we were not feeling safe and part of a clean environment.”

Levi’s pioneered the RSL and MRSL, establishing its own comprehensive lists which the brand updates annually to comply with global environmental regulations and chemical management.

“In 2012 [Levi’s] piloted a method for screening chemicals in our supply chain. Called the Screened Chemistry Program, it represents the future of chemical management by taking a hazard-based approach to identify and substitute best-in-class or better alternatives from the onset,” said Anna Walker, Levi Strauss & Co. senior director, policy and advocacy.

The program tests chemicals against health and environmental impacts so Levi’s can work with suppliers to create superior alternatives and areas to improve. The brand still uses their RSL and MRSL, but delves even further into sustainability by utilizing Screened Chemistry to look at hazard versus risk.

According to Walker, Levi’s requires supplier factories to prioritize responsible chemical management, and to work closely with suppliers and analytical labs to ensure that factors are met throughout the supply chain.

“It’s not about designing our perfect list, but rather ensuring we create the best products for our consumers. We believe the RSL and MRSL in partnership with our Screened Chemistry Program achieve that,” said Walker.