How Crocs is reducing the carbon footprint of its clogs

Crocs is progressing at a steady pace to increase the bio-based materials in the 150 million pairs of shoes it sells each year. The strategy underpins the company’s net-zero target for 2040.

A quarter of the material in Crocs shoes now features “bio-circular” materials, up from 17.3 percent in 2023, the company shared Sept. 5. “Bio-circular” materials repurpose cooking oils and paper industry process waste. The clog maker has come halfway toward its goal, set in 2021, to use 50 percent bio-circular content by 2030.

Crocs’ shuffle away from entirely fossil-based materials helped to reduce its absolute emissions by 3 percent in 2023. The carbon footprint of each pair of its clogs has dropped by 6.1 percent over 2021, according to the Broomfield, Colorado-based brand.

“When we look across our emissions, 97 percent of our emissions are in our supply chain, which means indirect control,” Deanna Bratter, Crocs’ vice president and global head of sustainability, told Trellis. “We really have to partner with material suppliers, manufacturers, transportation distribution providers to actually impact and drive the change.”

What’s changing inside Crocs

Crocs’ proprietary Croslite compound blends ethylene-vinyl acetate (EVA), deriving from crude oil, with other ingredients. Croslite comprises 80 percent of the materials the 22-year-old company buys.

“It gives us a clear place where we know we can make a scalable impact if we purchase the right way,” Bratter said. “We identified the right way in terms of bio-circular materials, which not only help reduce our dependence on fossil based inputs, but also we’ve been able to, through [lifecycle analysis] work, reduce our carbon emissions.”

Crocs uses the term “bio-circular” to describe bio-based material that’s “circular” because it uses feedstocks from waste or waste byproducts. The basis for the ingredients includes industrial-scale spent cooking oils from the food industry and tall oil, a byproduct of paper milling and recycling, Bratter said.

Although the non-fossil materials cost more money, Crocs is not elevating prices, she added. Crocs’ “Classic Clogs” style retails for around $40.

Crocs deserves credit for its transparency around even modest emissions reductions related to sourcing, according to Julia Freer Goldstein, content strategist at JLFG Communications and co-author of the book “Materials and Circularity.”

Working with suppliers

Crocs’ 2023 sustainability report counts 314 suppliers for its Crocs and Hey Dude brands. Many Crocs suppliers are big fossil chemical producers. Others, “in the innovation space,” are less widely known, Bratter said.

When launching its bio-circular effort several years ago, Crocs partnered closely with Dow on its Equilibrium technology, a technical process that results in the bio-circular material. 

“Since then, we’ve added several suppliers so that we can create some differentiation in the supply chain, which also helps us create competitiveness for pricing and managing sourcing,” Bratter said.

Footwear steps forward

Crocs is an early mover among shoe companies exploring alternatives to fossil materials to reduce their carbon footprints. “Looking at the fashion and footwear industry, sustainability has a long way to go, and there’s a huge amount of importance in really thoughtful steps forward,” Bratter said. “I hate to be cliche with, ‘Don’t let perfection be the enemy of progress,’ but it’s really true, and so we see this as such an important step in understanding our material.”

The company became a founding member of the Cambridge, Massachusetts-based Footwear Collective in 2023. It collaborates with New Balance, Brooks, Target and others on circularity efforts. 

Because EVA, used in Crocs, is so common in the soles of sneakers and many other shoes, Bratter said she hopes the company’s activities with biomaterials might spread across the footwear industry.

Crocs belongs to a minority of footwear companies rolling out shoes with bio-based materials. According to the Footwear Distributors and Retailers of America (FDRA):

Only 34 percent of shoe companies used more bio-based materials in 2023 than in 2022. That fell from 41 percent in 2022. More than half of shoe companies said in 2023 they would use more bio-based materials in upcoming products, up from 44 percent in 2022. Crocs began incorporating recycled materials in 2021. In 2020, 61 percent of shoe companies did so.

Among the solutions coming out of shoe brands’ skunkworks: Asics is selling recyclable Mirai sneakers; On is offering “circular” running shoes with bio-based ingredients and Puma is experimenting with biodegradable kicks.

Controversial materials accounting

Crocs uses a method called mass balance, certified by third-party ISCC Plus, which follows the total material inputs and outputs of byzantine supply chains. Food and chemicals businesses have used mass balance for years.

“I think the story with Crocs is very similar to Lego: the use of these mass-balanced materials does help companies scale up their use of bio-based feedstocks, and that’s a good thing,” said Anthony Schiavo, principal analyst at Lux Research. “However, there’s a risk that consumers will feel misled if there’s a major gap between the advertised bio-based content, based on mass balancing, and what’s physically present.”

Things get fuzzy because companies can’t trace the paths of individual molecules through suppliers’ chemical processes and into individual products. Therefore, mass balance could result in a brand calling a product 20 percent biobased, even if the product features a fraction of bio-based material.

“This creates risk of consumer backlash, and could encourage the sentiment that these consumer [sustainability] efforts are all greenwashing, which is counterproductive,” Schiavo said.

With that in mind, Crocs does not say individual shoes contain a specific level of bio-circular content, Bratter said. Instead, the company describes the total percentage of bio-circular ingredients used in Croslight in a given year. “It can vary shoe to shoe, but on a whole, we’re being very transparent with that claim,”she added.

Keeping materials circulating

In addition to adopting fossil-free materials, Crocs has multiple efforts to keep its products and materials in use:

Crocs expanded its takeback program in May from 45 to 150 U.S. stores, plus a mail-in option. The company in 2023 donated 236,000 pairs of wearable shoes from takeback to Soles4Souls, a nonprofit that distributes them to people in need. Crocs is not yet sharing how materials within unusable shoes from that takeback program might be recycled. “Anything is on the table,” Bratter said. Seven percent of each pair of Crocs is made from post-industrial, recycled content, including waste from the injection molding process in its plants. Crocs recycles 45 percent of scrap Croslite material from production to make new shoes. Instead of cardboard boxes, Crocs is using plastic bags made of 100 percent post-industrial recycled content, which offer an 85 percent lower carbon footprint, according to the company.

“In terms of being able to integrate circular materials, and also at end of life, being able to process and repurpose, we absolutely have an advantage versus others that are more complex,” Bratter said. Crocs’ plastic footwear is relatively simple, and therefore more readily recyclable than, say, sneakers, with their fasteners and flashy panels. 

However, the company should be careful not to oversell circularity, Freer Goldstein said. “Part of the problem with circularity and circular economy, if it just goes around the circle once, that’s not it,” she added.

“You think like, ‘Oh great, this is this circular; this is going to go around or down, and then we don’t need any more input.’ No, you keep needing more input for every pair of shoes. You’re still making plastic shoes, and you’re still needing inputs. It’s just the source of the inputs has changed.”