What does “clean” mean when nothing is impact-free?

In most markets, 'clean', 'natural', 'responsible', 'conscious' and 'eco' have no legal definition in textiles. A garment can be 95% polyester and marketed as natural because it contains a small proportion of cotton, or because the print inks are water-based, or because the packaging is paper.

'Non-toxic' is the most misleading of them. Toxicity is a matter of dose and exposure route, not a property a material either has or lacks, so the phrase implies a binary that does not exist and sets up an unfalsifiable comparison against products that are also not poisonous.

Regulators have begun to move. The UK Competition and Markets Authority published its Green Claims Code in 2021, and the EU has been tightening rules on unsubstantiated environmental claims. The direction of travel is toward substantiation, which is welcome and slow.

OEKO-TEX STANDARD 100 tests a textile article for harmful substances against a limit-value list, with stricter thresholds for products intended for babies and for items in prolonged skin contact. Passing means the tested article did not exceed those limits.

What it is not: an environmental certification, a statement about the fibre's origin, a labour standard, or a guarantee about how the item was manufactured. A fully certified polyester garment is still a plastic-based garment. Certification is a floor for chemical residue, which is genuinely useful and much narrower than most swing tags imply.

The Global Organic Textile Standard is broader. It requires a minimum organic fibre content — 70% for 'made with organic', 95% for 'organic' — and covers processing chemistry, wastewater treatment and a set of social criteria through the supply chain, with third-party certification at each stage.

It also has boundaries. GOTS applies to natural fibres, so it cannot say anything about a polyester component. It does not measure carbon footprint. And crucially, a certificate covers a certified operation, not necessarily every product a company sells — which is why 'GOTS-certified cotton' on a garment made of several materials is a claim about one input.

Clean does not mean perfect or impact-free. It means knowing more about what we make, questioning what is actually necessary, substantiating what we say, and remaining honest about what we have not solved.

In practice that means: name the material and where we can trace it to; leave out components that exist for marketing rather than function; design for years of use and for repair rather than replacement; publish the reasoning, including the parts that are unresolved; and never make a health claim we cannot source.

For the Heritage Sauna Hat, the honest version reads: traceable natural wool, felted with water, heat and pressure, unlined and undyed. Wool has a real environmental footprint. We chose it because it is the correct material for a hot room, it lasts for years, and it can be traced. Those are trade-offs we can defend, not an absence of trade-offs.

We do not yet have full supply-chain certification across everything we plan to make. We have not solved end-of-life for products we have not designed. We do not have lifecycle assessment figures we would be willing to publish, and we would rather say that than estimate.

This section will get longer before it gets shorter. That is the point of it.