Healthy Undies
Women's Health

Fabric Guide: How To Choose The Best Eco-Friendly & Sustainable Underwear

Fabric Guide: How To Choose The Best Eco-Friendly & Sustainable Underwear

With so many sustainable underwear brands claiming that their fabric is the most "eco-friendly” and the “most breathable” how can you be sure if you are making the right choice? In this guide to high-quality materials, you will find some of the most sustainable fabrics for women's underwear.... along with the worst, to help you decide which is the right fit for you!

We will be diving into the lifecycle analysis and the Higg's index parameters of the most common underwear fabrics on the market today, including:

  • Modal: a semi-synthetic fabric made from beech tree pulp
  • TENCEL™ Modal (may be referred to as Lenzing Modal): created from a sustainably harvested forest in Austria
  • TENCEL™ Lyocell (may be referred to as Lenzing Lyocell or simply Tencel): made from Lyocell and Modal, "regenerated cellulose" fibers.
  • Cottonmade from the natural fibers of cotton plants
  • Organic Cottongrown using methods that have a low impact on the environment
  • Nylon: a synthetic fabric that is derived from crude oil
  • Polyestora synthetic fabric that's usually derived from petroleum

Eco-Friendly Lingerie: Why Choose Sustainable Underwear Brands?

We all know that textile waste is a massive worldwide problem. A staggering two-thirds of our clothing is made from fossil fuel synthetics, and 85% of this material is sent to landfills, unable to decay or decompose. Not only that, but according to a report on the textiles industry from the Ellen MacArthur Foundation, clothing production approximately doubled from 2000 to 2015. Clearly demands for sustainable fashion are at an all-time high.

As we start to add more sustainable options to our wardrobe, it's only right that we should see that positive change in our underwear drawers too, by switching to sustainable and ethical undies.


Sustainable Modal Underwear

What is Modal?

Modal is a “semi-synthetic” fabric fiber that is commonly combined with other fibers to create a soft and long-lasting material. It's silky-smooth feel makes it more luxurious than other fibers and it is usually found in higher-end sustainable underwear

TENCEL™ Modal vs Modal?

TENCEL™ Modal is produced in Austria and mainly composed of beechwood pulp that is made into cellulosic fibers. In addition to the low environmental impact of the harvest and production process, the fibers are biodegradable and compostable, allowing them to eventually revert back to nature.

Impact on the Environment: TENCEL™ Modal

Modal is manufactured from cellulose using chemical processing, the same as bamboo, rayon (viscose) and lyocell. In the case of TENCEL™ Modal, the cellulose comes from a blend of different hard woods, where the manufacturing process has a recovery rate of approximately 75%. This means that the chemicals used in processing are captured and reused. 

Such chemicals as furfural, sodium sulphate and xylose. The small amount discharged is considered non-hazardous. For more information, learn more about Lenzing’s biorefinery.


1. Contribution to Acid Rain Emissions

Acid rain is caused by a chemical reaction that begins when compounds like sulphur dioxide and nitrogen oxides are released into the air. This can happen during the fabric manufacturing process.

Acid rain has been shown to have adverse impacts on forests, freshwaters, and soils, killing insect and aquatic life-forms, causing paint to peel, corrosion of steel structures such as bridges, and weathering of stone buildings and statues as well as having impacts on human health.

Lenzing™ Modal contributes 0.02 SO2-EQ (acidification potential) to the environment. This is one of the lowest scores across all usual underwear fabric choices, including cotton:

2. Bluewater Footprint

Bluewater Footprint refers to water that has been sourced from surface or groundwater resources and is either evaporated or incorporated into the fabric during production. This footprint helps us understand for what purposes our limited freshwater resources are being consumed and/or polluted. 

Lenzing™ Modal uses 0.04 M2 per KG of water during process. Again, this another very low score across all fabrics tested, making it an ideal candidate for sustainable underwear.

3. Contribution To Climate Change

CO2 (carbon dioxide) emissions are the main contribution to global warming and climate change. Textile production is one of the most polluting industries, producing 1.2 billion tonnes of CO2 per year. Around 5% of total global emissions come from the fashion industry.

Compared to other underwear textiles, Lenzing™ Modal's contribution to CO2  is very low at just 1.5 CO2-EQ per KG.

4. Cumulative Energy Demand 

The Cumulative energy demand (CED) of a product represents the direct and indirect energy use in units of MJ throughout the life cycle, including the energy consumed during the extraction, manufacturing and disposal of the raw materials.

In the case of Lenzing Modal, that number is a relatively low 21 (MJ) 

We use Lenzing™ Modal fabric in the outer layer our best-selling thongs, briefs and cheeky undies, which makes them super soft and hugely popular with our customers.

TENCEL™ Lyocell

Tencel Underwear

What is TENCEL™?

TENCEL™ is actually a brand name owned by the Austrian company Lenzing AG. The brand is used for their Lyocell and Modal fibers.

TENCEL™ Lyocell is a cellulose fibre that comes mainly from eucalyptus trees blended with other woods. It is made by dissolving wood pulp and using a special drying process called spinning. According to Lenzing AG, it is 50% more absorbent than cotton and naturally less susceptible to odorous bacteria growth because of its fiber properties.

Impact on the Environment: TENCEL™ Lyocell

1. Contribution to Acid Rain: TENCEL™ Lyocell contributes 0.01 SO2-EQ (acidification potential) to the environment. This is also one of the lowest scores across all fabric choices.

2. Bluewater Footprint: TENCEL™ Lyocell uses 0.02 M2 per KG of water during process. One of the lowest score across all fabrics tested, making it an ideal candidate for sustainable underwear.

3. Contribution to Climate Change: Compared to other underwear textiles TENCEL™ Lyocell's contribution to CO2  is very low at just 1.5 CO2-EQ per KG, exactly the same as Lenzing Modal.

4. Cumulative Energy Demand: 21 (MJ) 

TENCEL™ Lyocell is the fabric we use for the inner layer of our thongs, briefs and cheeky undies. Plus our lining is infused with zinc oxide, a naturally soothing, anti-microbial mineral.


Cotton Underwear

What is Cotton?

You know cotton as one of the most common undergarments fabric. Cotton is primarily composed of cellulose, an insoluble organic compound, that is spun into yarn and woven to create soft and durable fabric. 

Conventional production practices for cotton involve the application of substantial fertilizers and pesticides (can you say toxic chemicals?), which threaten the quality of soil and water, as well as the health of biodiversity in and downstream from the fields. 4% of all world pesticides and 10% of insecticides are used in cotton-growing.

Cotton underwear is commonly prescribed to women as the most "breathable" option, but has fabric technology outgrown this old school recommendation?

Cotton vs. Organic Cotton?

In comparison certified organic cotton is equally as comfy, but grown using methods and materials that have a lower impact on the environment than conventional cotton. Organic production processes replenish and maintain soil fertility, reduce the use of toxic and persistent pesticides and fertilizers, and build biologically diverse agriculture, all while encouraging fair trade practices.

Impact on the Environment: Organic Cotton

1. Contribution to Acid Rain: Organic Cotton contributes a not-so-great score of 5.7 SO2-EQ (acidification potential) to the environment. However, it is significantly better than conventional cotton which has a score of 18.7!

2. Bluewater Footprint: Organic Cotton uses 0.75 M2 per KG of water during processLow compared to 2.12 M2 per KG of conventional cotton.


3. Contribution to Climate Change: Compared to other underwear textiles Organic Cotton contribution to CO2  is very low at just 0.98 CO2-EQ per KG. Conventional cotton has a score of 2.12 CO2-EQ per KG.


Nylon Underwear

What is Nylon?

Nylon is the name of a family of synthetic polymers often utilized to construct sheer panelling and lace found in lingerie, and often spun with a high count spandex for greater elasticity. Unlike other organic or semi-synthetic fibers, nylon fibers are entirely synthetic. The use of this type of synthetic polymer in clothing began with a desire to find alternatives to silk and hemp for parachutes in World War II. And even though you can find recycled Nylon on the market today that is made from plastic bottles, the biodegradability is still a major question mark. 

Impact on the Environment: Nylon

1. Contribution to Climate Change: Nylon's contribution to CO2  is a whopping 22 CO2-EQ per KG!

2. Cumulative Energy Demand: 418 (MJ) 


Polyester Underwear

What is Polyester?

Polyester is a generalized term for any fabric or textile, which is made using polyester yarns or fibres. It is a shortened name for a synthetic, man-made polymer, polyethylene terephthalate.

Polyester fabrics don’t absorb perspiration, or other fluids, leaving the wearer with a moist, clammy feel. Polyester fibers also typically have a low level of wicking. Since it’s a man-made fiber derived from petroleum-based products, polyester is not sustainable, nor is it biodegradable, though you'll commonly find this fiber in lingerie stores and your own top drawer.

Impact on the Environment: Polyester

1. Contribution to Acid Rain: Polyester contributes 8.67 SO2-EQ (acidification potential) to the environment.
2. Contribution to Climate Change: Compared to other underwear textiles, Polyester's CO2  contribution is 2.13 CO2-EQ per KG.

3. Cumulative Energy Demand: 32 (MJ) 
Higgs Index Score

Overall Outlook on Eco-Friendly Underwear Fabrics

Eco Friendly Underwear Fabrics

Eco Friendly Underwear Brands

The Higg Materials Sustainability Index (Higg MSI) is the apparel industry's most trusted tool to measure and score the overall environmental impacts of materials. It is essentially a summary measure of the overall performance of a fabric from the raw material to the fabric formation stage (‘from cradle to gate’). The lower the score, the lower the fabric’s impact.

Surprisingly, conventional cotton had the worst score of all the fabrics listed above. In order of best to worst, they were:

  • Lenzing Tencel: 33
  • Polyester: 45
  • Organic Cotton: 41
  • Nylon: 55
  • Cotton: 90 

In conclusion, it can be very tricky to find out if your are buying ethical underwear that uses sustainable fabrics. Being 100% sustainable is a rarity, but there are certain things you can look out for when researching brands.

Look for brands that are OEKO-Tex, Lenzing or GOTS certified organic cotton to avoid brands that 'green wash' their products. Or use this guide as a reference when researching sustainable underwear brands and textiles in the future! 

For a comprehensive list of fair trade certified lingerie brands with eco friendly supply chains, we recommend checkin gout Azura Bay. There you'll find plenty of size-inclusive women's underwear brands made from sustainable materials. Find a list to ethical underwear brands here.

TENCEL™ is a trademark of Lenzing AG.

Sources of reference here.

Back to blog
Not just underwear, undercare