Coterie Diapers
A premium, highly-absorbent diaper that uses strict TCF processing.
Understanding TCF (Totally Chlorine-Free) vs. ECF in Diapers
Is totally chlorine-free really necessary, or just a premium marketing tactic? We break down the science of diaper bleaching.
R
By Renee, R3 Founder
Environmental Toxins Analyst
Updated June 2026
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The quick answer
Diapers are filled with wood pulp (fluff) which must be bleached clean. "ECF" (Elemental Chlorine-Free) uses a chlorine derivative (chlorine dioxide) which is vastly safer than old methods but can still leave microscopic traces of Dioxins, which are highly toxic environmental pollutants. "TCF" (Totally Chlorine-Free) uses oxygen or ozone for bleaching, guaranteeing absolutely zero Dioxins are produced. TCF is the gold standard for purity and environmental safety.
In this guide:Coterie DiapersKudos Diapers
Editor's note. This guide evaluates the presence of Dioxins and Furans generated during pulp processing.
01
Why Bleach at All?
Diaper manufacturers bleach wood pulp because, to make an absorbent diaper core, they shred wood into a fibrous pulp that in its natural state is brown and full of lignin, which repels water. Bleaching removes the lignin, making the fluff soft, highly absorbent, and bright white.
Historically, manufacturers used elemental chlorine gas, and the result was an environmental disaster: the bleaching process dumped massive amounts of Dioxins (the highly toxic environmental pollutants documented by the EPA) into rivers. The industry's later shift to chlorine dioxide cut Dioxin creation by over 90%, but only abandoning chlorine entirely eliminates it.
Dioxins are among the most toxic environmental pollutants known to science. We want them nowhere near a baby's most sensitive skin.
Renee Says
In short
- Bleaching is required to make wood pulp absorbent.
- Old methods used chlorine gas, creating toxic Dioxins.
02
ECF vs. TCF
ECF (Elemental Chlorine-Free): ECF bleaching, adopted after environmental outcry, uses Chlorine Dioxide instead of raw chlorine gas. ECF significantly reduces Dioxin creation (by over 90%) but does not mathematically eliminate it. The vast majority of standard diapers (Huggies, Pampers, Honest, Kirkland) are ECF.
TCF (Totally Chlorine-Free): TCF processing abandons chlorine entirely, using hydrogen peroxide, oxygen, or ozone to whiten the pulp. Generating Dioxins is mathematically impossible with this method, which is why premium non-toxic diaper brands obsess over TCF certification.
ECF bleaching cuts Dioxin creation by over 90% but cannot reach zero; TCF processing, which uses oxygen, ozone, or hydrogen peroxide instead of any chlorine compound, makes Dioxin formation impossible.
In short
- ECF reduces Dioxins but does not eliminate them.
- TCF uses oxygen/peroxide, generating zero Dioxins.
- TCF is better for the environment and the baby.
The bottom line
Is ECF "dangerous"? Not necessarily; the trace amounts of Dioxins are incredibly tiny. But is TCF better? Unquestionably. If you have the budget, opting for a TCF diaper eliminates an unnecessary chemical exposure variable while being vastly superior for the global water supply.
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Frequently asked questions
Common questions about toxicology: materials, answered by our research team.
QAre Bamboo Diapers automatically TCF?
No, bamboo diapers are not automatically TCF; just because a diaper is made from bamboo does not mean it was bleached safely. Bamboo pulp must also be bleached, and many cheap bamboo brands on Amazon use ECF processing. You must look strictly for the "TCF" label.