When it comes to sustainability, organic cotton is often compared to other fabrics to determine which is the most environmentally friendly option. Hemp, linen, Pima cotton, semi-synthetic fibers, and polyester are some of the fabrics that are commonly compared to organic cotton.

Hemp fabric is highly regarded as one of the most sustainable fabrics. It requires around 300 to 500 liters of water to grow 1 kg and doesn’t require pesticides and fertilizers to grow well. Hemp grows faster, has an even smaller land-to-product-yield ratio, has a regenerative effect on soil quality, and is a carbon-negative raw material that absorbs more CO2 than forests. However, hemp is a little less soft than both organic and regular cotton.

Linen fibers are shorter than both hemp and cotton fibers, making the fabric lighter and more breathable, but less durable. Linen is derived from the flax plant, and like hemp and organic cotton, it’s not water-intensive and is grown without chemicals. Organic cotton will withstand everyday wear and tear better than linen.

Pima cotton is an extra-long staple cotton grown from the Gossypium barbadense plant. These longer individual cotton fibers make them a better quality (softer and silkier), and far more durable and resistant to wrinkles, fraying, and tearing than normal cotton. While not organically grown, Pima cotton is often compared to organic cotton. However, there are far more claims of Pima cotton than there is actual cultivation of it.

Semi-synthetic fibers, such as bamboo, cupro, lyocell, and modal fabric, are made by dissolving plant cellulose and plasticizing it into a soft fabric. These fabrics require minimal water to grow and process, but they require chemicals to break down the plant pulp. Organic cotton requires no solvents and is still the more sustainable option.

Polyester is a synthetic fabric made of petroleum, which doesn’t break down in the soil. Polyester can withstand a lot of wear and tear, but its durability is an indication of how awful it is for the planet. Polyester releases dangerous microplastics into the environment each time it’s worn and washed. While it’s cheaper than organic cotton, the costs are picked up by the planet and the people who are involved with the chemicals required to process the fabric. The best bet for sustainable activewear is to look for mostly cotton activewear with a little bit of polyester (ideally recycled) to give it that stretchy, moisture-wicking quality necessary for workout clothing.