The single most important thing to understand about sustainable fashion is that it doesn't exist—not really. Sustainability, in environmental terms, is a state of equilibrium, where resources are used so seldomly and in such low quantities that they never reach depletion and the creation of something new isn't done at the expense of some future harm. True sustainability requires deliberate and persistent attention to the entire life cycle of a product and even (at times) a skeptical eye toward that product's existence in the first place.
The incentives of the fashion industry—being, largely: Make new stuff and get people to buy it for as much profit as possible, as often as possible—are tacitly at odds with the idea, but that hasn't stopped brands from trying to appeal to people's growing concerns about our warming planet by making their products appear less problematic (a marketing strategy known as "greenwashing").
This is possible, in part, because few people understand how clothes are made today—that, particularly for the best known and most profitable brands, there is a complicated global supply chain that unfurls from each garment, one that can be completely different from item to item, even within the same brand. It could look like cotton being grown in one country, spun into yarn in a second, woven into textiles in a third, cut and sewn in a fourth, and sold in a fifth. Or at one of those points, the company contracted to perform one function might hire several smaller companies to help them complete the order, often due to massive workloads with impossibly short deadlines. The whole convoluted process creates several layers of abstraction, which shields the overarching brands from liability for whatever happens below them in the supply chain and makes it conveniently difficult to follow up on vague claims of being "environmentally friendly".
This is all to say: If you encounter a brand that seems a little too eager to claim that its products are critical to fighting climate change, pause. And if you come across any of the following words as you're browsing the internet for a new outfit, this is what they're supposed to mean.
Transparency: Brands that lean into transparency share important information—factories, workers' names, materials used, etc.—at all junctures of the production process. It's an important quality that can help you determine whether any of the words used to describe a brand's environmental impact and approach are greenwashing or not.
Sustainable, Eco-conscious, Eco-friendly, Environmentally friendly, Green: These words are meant to convey something about the environmental priorities of a brand and the people who run it, but they don't mean much in any verifiable way. They suggest a concern for the adverse impacts of fashion on climate change and global warming, but they don't necessarily speak to anything concrete.
Ethical: This suggests that ethical guidelines and human rights concerns have been considered throughout the creation of the garment, but it's also difficult to verify, so it's important to understand how transparent the brand is with its customers and auditors.
Conscious, Responsible: These words are meant to describe a brand as being committed to minimizing its negative environmental and ethical impacts. Similar to the above terms, it's difficult to substantiate without a lot of transparency from the brand.
Circular: This means that the entire life cycle of the garment has been considered and designed for—from the growth of the raw materials to the recycling or disposal of the final product. The company takes ethics and human rights into account and is transparent about its processes through all stages.
Fair Trade: The product meets a list of internationally agreed upon social, environmental, and economic standards, particularly if the product description features The Fairtrade Mark.
Slow fashion: This is meant as an adversary to fast fashion. It suggests a rejection of frequent conspicuous consumption, trend cycles, and ethically suspect labor practices.
Greenhouse gas emissions: This usually refers to carbon dioxide, methane, and nitrous oxide, but it technically also includes fluorinated gasses. When emitted (by human activities like burning fossil fuels for heat, electricity, or transportation), they trap heat that would otherwise escape the atmosphere, contributing to global warming.
Carbon footprint: The total amount of greenhouse gasses generated by a person’s or entity's actions.
Carbon offset: An action taken to balance out the negative effects of greenhouse gas emissions. Some examples are reforestation programs and investments in renewable energy.
Carbon neutral: The amount of greenhouse gas emissions that this person or entity typically creates have either been eliminated or balanced out as a result of carbon offsets. Because it's very difficult to have a fully carbon-neutral company—even if they eliminate emissions in production, it's unlikely that there aren’t any emissions associated with the distribution and delivery of their products—many companies buy carbon offsets, like tree-planting services, and use the term to make it seem like they're doing something about their environmental impact when they may not be changing much about their day-to-day processes.
Organic: The materials used for the product were grown according to organic farming standards, which means they weren’t grown using pesticides, genetically modified organisms (GMOs), or other harmful synthetic chemicals.
Biodegradable: Because of the materials it's made from (most likely untreated organic cotton, silk, or hemp), the product can break down naturally, usually without creating any harmful byproducts.
Natural: A term often misused by fashion brands, “natural” generally describes something—usually materials—occurring in nature like cotton, bamboo, hemp, and wool.
Synthetic: The opposite of “natural”. This is used to describe something that is man-made. In fashion, this can usually signal the involvement of petroleum-based materials (plastic), but synthetic fibers can be made from both natural or synthetic polymers. Some synthetic fibers made from natural polymers are biodegradable (Tencel, lyocell), but other textiles like organic linen or recycled cotton are still better for the environment. Products made of hybrid natural-synthetic fibers might sound like a nice compromise, but they're kind of the worst: They’re usually not biodegradable and also extremely difficult to recycle. Typically, the more synthetic a garment and its materials are, the more likely it is to have negative environmental consequences at the end of the product's life cycle.
Vegan: This describes a product that was made without any animal-derived products or the involvement of animal testing. It’s important shopping information, particularly if you’re concerned about the ethical treatment of animals, but it can also signal the use of synthetics, so pay close attention.
Cruelty-free: This describes a product that was made without harm, endangerment, or injury to any animals.
Microplastics: Extremely small pieces of plastic debris that can break off of any plastic product. In the case of rigid plastics like bottles and containers, these usually take the form of microbeads, but in the case of clothing made from synthetic textiles derived from petroleum, this can look like microfibers.
Secondhand: Clothing that has been owned and usually worn before by at least one person. Secondhand clothes are usually sold at consignment shops, thrift stores, or online resale platforms, but just because you find an item at one of these retailers doesn't necessarily mean it's secondhand.
Vintage: Technically, a garment is considered "vintage" if it was made between 20 and 100 years ago, but lately, "vintage" is commonly used as a synonym for "secondhand". Anything older than 100 years is considered "antique."
Deadstock: This refers to items or materials that were made previously (as in, another decade) but never sold. Maybe a fabric company manufactured a textile that sat around in the warehouse for years or a clothing company made too many units of a design and a bunch of them were never sold. These products aren’t secondhand, but they’re not new either.
Recycled: If a garment is made of recycled plastic, this means that preexisting plastic was broken down to its most basic elements (usually through an energy-intensive industrial process) and then turned into new material to be made into a totally new garment. On one hand, this has been a useful way to move discarded plastics out of the waste stream (in landfills or in giant garbage patches in the ocean), but the production of these garments can still create emissions and chemical byproducts, and the final products are often not biodegradable (because they’re plastic!).
Upcycled, Repurposed, Reconstituted: Though sometimes misused to describe recycled products, upcycling is the creative transformation of secondhand clothes and previously used materials without completely breaking them down as you would in recycling. Anything, not just clothes, can be upcycled. If an object's function is transformed, it's upcycling. This can potentially result in waste from offcuts, but so can manufacturing new clothes from new or deadstock rolls of fabric. Generally, it's an environmentally sound process as long as it's practiced in moderation.
Zero waste: This is meant to indicate that any waste created from the production process of a garment was diverted to a new purpose rather than disposed of. It's an extreme description and extremely difficult to do at all levels of the supply chain, so be sure to look for transparency and verification.
Made-to-Order: Rather than make a bunch of stock and hope that it all sells, brands with made-to-order programs only produce a product once a customer has ordered it. This means there should never be any deadstock or wasted inventory sitting in a warehouse or (worst of all) a landfill.