Let's not beat around the bush, there's only one way to make sure there are no hazardous chemicals on our clothes : test it in a lab.
The fashion supply chain is so complex and fragmented. It's nearly impossible for one brand to overview each step of textiles & garment making.
We often think that hazardous chemical residues found on clothes are caused by dying (and scouring). It may be true most of the time but other processes at any stage of the supply chain are suspicious to leave traces.
That's why all the component of a finished garment needs to be tested if we want to make sure there are no hazardous chemicals traces on it.
Chemicals like :
→ (Heavy) metals
→ Pesticides (glyphosate)
→ Chlorinated phenols
→ Flame retardant
The list is long...
For this purpose of testing finished textile products, STANDARD 100 by OEKO-TEX® is the best known certification there is.
From my understanding, they will test every components of a product every year to make sure it's harmful chemical free (or that traces do not exceed limit values according to individual substances).
Certified STANDARD 100 by OEKO-TEX® products are rare but when you find it you can have confidence that hazardous chemicals aren't on your clothes. Look for it on product pages (website) and labels on clothes.
This certification does not mean there were no gas emissions or water discharges of hazardous chemicals.
Lowering the risk
There are things you can look for that won't guarantee a harmful chemical free garment but will significantly lower the risk.
→ Naturally dyed
Choosing tree & plant-based dyes will lower the risk of finding traces of potentially harmful products on your clothes.
Undyed clothes are usually off-white to light brown. No dye, no scouring, no wetting agent, no chemicals.
→ Second hand
Chemical on clothes do wash away. So when a if garment has been washed 10, 20, 50 times there's a good chance that the chemicals are gone (yes, in our water treatment systems...) or traces are lower.
→ Locally dyed
By locally I mean North America or Europe where environmental legislation is efficiently enforced and comprehensive enough to ban the use many hazardous chemicals for any kind of textile wet processing. Like the Canadian Environmental Protection Act in which the list of toxic substances include nonylphenol, benzidine, formaldehyde, (heavy) metals (mercury, lead, chromium compounds, etc.) and much more.
→ Avoid synthetic fibres
It's always more chemically intensive to dye plastic (azo dyes). By choosing natural (cotton, hemp, linen) or cellulosic (lyocell, viscose, modal) fibres, low impact reactive dyes (that leave next to no traces on your clothes) can be used.
Written by Ugo Dutil :
I grew up in the ecovillage Cite Ecologique. I like this way of life that values human relationships, sustainable development and personal growth. I’ve been working with Respecterre since 2013. I'm fascinated by hemp, minimalism, slow fashion, local supply chains, zero waste, viscose production and transparency.