Every color used to come from the earth
For most of history, the color in your clothes came from something that grew, crawled or was dug out of the ground. Blue from indigo leaves. Red from madder root and crushed insects. Yellow from weld, a wildflower.
That changed in 1856. William Henry Perkin, an 18-year-old chemistry student in London, was trying to make a malaria drug from coal tar and ended up with a purple goo that dyed silk. He called it mauve. It became the first synthetic dye sold at scale, and it started the industry that colors almost everything you own today.
Plant-dyed clothing goes back to the older way. It's one of the most beautiful choices in a natural-fiber closet, and it comes with a few things worth knowing.
What the badge means
The brand states that this piece gets its color from plants instead of synthetic dyes. In our catalog that includes indigo, madder root, weld, logwood, pomegranate, avocado pits and herbs like turmeric.
Some brands call it natural dye, botanical dye or vegetable dye. We use one badge for all of them, and only when the brand says the color came from a plant. Colors described as "natural mineral" dyes don't count.
Why synthetic dye chemistry matters
Most synthetic dyes are allowed and most are fine. The problem sits in one family. Azo dyes are a large group of synthetic dyes, and some of them can break down into chemicals called aromatic amines that are linked to cancer.
The European Union bans those azo dyes above 30 milligrams per kilogram in anything that stays against your skin for long stretches, like clothing, bedding and towels. The US has no matching limit for adult clothing.
Plant dyes skip that chemistry. There's no azo dye in a madder-root sweater, because there's nothing synthetic in the dye bath to break down.
The mordant question
Plant dyes come with one catch, and it's the question that separates a good plant-dyed piece from a vague one.
Most natural dyes don't hold on to fiber well by themselves. To make the color stick, dyers soak the fabric in a mordant, from a Latin word meaning "to bite." Traditional mordants are metal salts: alum, iron, tin, zinc, copper and chromium.
A 2024 review in the journal Environmental Science and Pollution Research found researchers still use those metal salts widely, and that the metal ions they release into wastewater cause major damage to ecosystems. That's why newer work focuses on bio-mordants, plant-based fixers like tannins from oak galls, pomegranate rind or tree bark.
Chromium is the one to pay closest attention to. The EU caps chromium VI, a form linked to cancer, at 1 milligram per kilogram in clothing. Plant dye fixed with a chromium mordant still puts a metal the EU restricts into the dye bath.
Ask the brand
- Which mordant do you use? Plant tannins and alum are the common answers. Chromium is the one to question.
- Is every color plant-dyed? Some brands plant-dye a few colorways and use conventional dyes for the rest.
- Is the fabric itself natural? Plant dyes don't take on polyester. A brand selling "plant-dyed" polyester has a story to explain.
What to expect when you wear it
Plant colors are alive in a way synthetic colors aren't. Two of the same shirt can come out a shade apart, because the plants, the water and the weather change from batch to batch.
They also soften over time, faster in sun and hot washes. That's normal and part of the look. Wash plant-dyed pieces cold with a gentle soap, skip the dryer when you can and dry them out of direct sunlight. New pieces can bleed a little at first, so wash them on their own.
Some colors hold better than others, so ask the brand how its shades wear over time.
Why we flag it
The clothes you wear are a health choice, the same way food is, and dye is one of the main ingredients nobody lists. A plant-dyed piece tells you what made its color, and that's rare.
We show the badge for that reason. It never changes a Toxome Score, which comes from the fabric itself. It's one more fact to have before you get dressed.
Curious how it works at home? Try our guide to 5 food waste scraps that make non-toxic fabric dye.
Keep reading
Sources
- Science History Institute. The Story of Mauve.
- Science History Institute. William Henry Perkin (scientific biography).
- European Chemicals Agency (ECHA). Annex XVII to REACH, Entry 43: Azocolourants and azodyes.
- European Commission. (2018). Commission Regulation (EU) 2018/1513 (Entry 72, including chromium VI in clothing).
- Benli, H. (2024). Bio-mordants: a review. Environmental Science and Pollution Research, 31, 20714–20771.
FAQ
Plant dyes skip the synthetic dye chemistry used on most clothing, including the azo dyes the EU bans because they can release cancer-linked chemicals. How a piece was mordanted matters too, so ask the brand which fixer it uses.
They soften faster than synthetic dyes, especially in sun and hot washes. Wash cold with gentle soap and dry out of direct sunlight to keep the color longer.
A mordant is a fixer that helps a natural dye bond to fiber. Traditional mordants are metal salts like alum, iron or chromium. Bio-mordants use plant tannins instead. Chromium is the one to question, because the EU limits chromium VI in clothing.
Not in any practical way. Plant dyes bond to natural fibers like cotton, linen, silk and wool. Polyester is a plastic, and it needs synthetic disperse dyes applied under heat and pressure.
No. Origin and process badges come from what the brand states about each product. We don't audit factories, so these badges are information, not verification. They never change a Toxome score, which comes from what the garment is made of.
