An eco-friendly sportswear company may be poised to shake up the industry by ditching familiar product materials and as it weighs going public. San Francisco-based Allbirds Inc. expanded its product line from sneakers to apparel in a move that challenges the likes of Nike and Lululemon.

While industry titans have made inroads in environmentally friendly workout clothes, Allbirds has taken it a step further with athletic gear made entirely of sustainable material.

Gone are synthetic fabrics. In their place? Merino wool and yarn from the pulp of eucalyptus trees.

Some consumers might be wary of wool material for workout clothing but it can absorb up to 30% of its weight in moisture and also regulate temperature, according to Tim Brown, the company's co-chief executive.

“Tim and I have been focused on not just making products out of natural fibers in order to make them sustainable but to make them better products,” Allbirds co-CEO Joey Zwillinger told the Wall Street Journal.

“We think we can exceed the performance expectations of what’s out there.”

Allbirds is already a hit with environmentally conscious consumers who are eager to reject polyester -- a synthetic fiber derived from oil and which uses harmful chemicals like carcinogens in its production.

“There is a new group of consumers who are completely aware that climate change is the problem of our generation, and yet they’re running around in plastic leggings with plastic shoes,” Brown told the Journal.

Both Nike and Lululemon use lightweight, moisture-repelling material. Nike uses 90% polyester and 10% latex for its leggings. Lululemon uses a material called Luon, which is trademarked by the brand, and is 86% nylon and 14% Lycra.

Allbirds started off in 2016 with a line of shoes made of the same merino wool, laces made from recycled plastic bottles, and insoles produced by using castor bean oil. Prices for shoes range from about $95 to $135.

In 2020, Allbirds created an apparel line called "XO" that is made from wool and fiber derived from discarded shells of marine life.

The Journal estimates that Allbirds is valued at about $1.7 billion after rounds of funding in 2018 and 2020.

There has been growing talk of Allbirds going public and as early as September. The company has not commented about plans to go public.