Most babies in France wear single-use nappies, about 4000 of them over the first three years, so this is skin contact that adds up.1 In 2019, France's health and safety agency, ANSES, published its assessment of the safety risks in baby nappies.1,2 Its experts identified traces of chemicals nobody adds on purpose: dioxins, which can form when pulp is bleached with chlorine-based agents, and PAHs, a family of chemicals that can form when materials are overheated during manufacture.1,3,4
It also found fragrances added on purpose, some of which could cause skin allergies.1 Under the exposure scenario ANSES judged most reliable, its estimates flagged cancer risks from the most potent PAHs, along with possible effects on the nervous system and behaviour.5 EU scientists later concluded that the risk could not be demonstrated for some of these chemicals and could not even be sized up for others.6
So the honest picture is this: the traces are real, the size of the risk is disputed, and words like 'gentle' or 'dermatologically tested' on a pack don't tell you whether a nappy was checked for any of them. YAN's view: something a baby wears against their skin day and night for years should carry no added scent and as little of these unwanted traces as makers can manage, because a disputed risk estimate is not proof of safety.
What you need to know
- Germany's Federal Institute for Risk Assessment says there are no bans on skin-allergy scents in disposable nappies and no duty to declare them, unlike cosmetic products.2
- Disposables do real good: modern nappies reduce the risk of nappy rash (diaper dermatitis), one of the most common skin diseases in infancy.5
- Studies that fully measure how much of these chemicals crosses a baby's skin are still missing, and so is population data showing health effects from wearing nappies.7
Where the worry started
The same question was raised long before France's tests, in an American newspaper report on dioxin in paper products that described tests finding it in superabsorbent disposable diapers, as well as in paper towels and paper plates.8 The report quoted an internal industry memo, dated December 1986, saying the real reason for a joint study was to "forestall major regulatory and public relations difficulties".8
Dr Ellen Silbergeld, a toxicologist with the Environmental Defense Fund, put the concern plainly: "We're talking about direct human contact".8 Dr Jake Ryan, a research scientist at Health and Welfare Canada, Canada's equivalent of the American food and drug regulator, was blunter: "We just don't know".8 Bleaching has changed since then, which is why the French tests matter: they put the same question to modern nappies, and the traces were still there.
How do chemicals get into a nappy?
ANSES's recommendations point to where the unwanted traces start: raw materials that may already be contaminated before manufacture, heating that can form PAHs, bleaching processes and certain dyes.4 That matters for shoppers: you can't pick a nappy without these traces by reading an ingredients list, because they were never ingredients.
Nappy pulp is no longer bleached with elemental chlorine, but chlorinated agents such as chlorine dioxide, a chlorine-based bleach, are still used and can form dioxins.3 Some researchers say today's elemental chlorine-free or total chlorine-free bleaching prevents dioxins from forming.5 One proposal goes further: to limit dioxins and furans, bleaching could be done without any chlorinated agents at all, chlorine dioxide included.3 That removes one way dioxins form in the pulp, not traces that get into a nappy by another route.
How big is the risk?
The Risk Assessment Committee of ECHA, the EU's chemicals agency, found ANSES's PAH figures inconclusive, because the estimate relied on the limits of quantification of a poorly sensitive analytical method.6,9 In plain words, the lab could not see small amounts, so the smallest amount it could reliably measure stood in for whatever was really there, which pushes an estimate up.
Germany's Federal Institute for Risk Assessment made a similar point: 'The approach chosen by ANSES serves as an approximation method to estimate maximum exposure.'2 So ANSES's figures were built to estimate the most a baby might take in, not to show what a typical baby takes in.
A study of six international brands bought in Swiss shops estimated that the median daily dose of total PAHs a baby gets from breast milk, worldwide, is 171 times greater than from the nappy's core and top sheet.9 By the researchers' sums, a nappy adds only a small share of the PAHs a baby takes in. Breastfeeding's benefits are well established, and this comparison does nothing to change that.
But that study looked at PAHs only, so it tells us nothing about dioxins or scents.
EDANA, the nonwoven industry association, said the French study 'does not demonstrate that any product has exceeded existing safety thresholds'.10,11 EDANA's members had set up a taskforce in 2017 to agree test methods and develop 'safe and acceptable threshold limits' for trace impurities in finished products.10 The statement as quoted does not say which thresholds it means or how products were tested, so hearing that the study does not demonstrate an exceedance tells a parent little about what was checked.
What do the rules say?
ANSES proposed EU-wide rules to minimise almost 200 substances in nappies, including PAHs, dioxins and formaldehyde.4 ECHA's expert committees did not back it.6 Campaigners at ClientEarth, an environmental law group, read the same opinion differently: because the substances are harmful and babies may be exposed for a long time, they said, 'ECHA cannot rule out the existence of a risk to babies’ health'.12
A written response in the EU debate said it believed that setting values for traces nobody adds on purpose, under the POPs Regulation, would be 'a more efficient tool than a REACH restriction in this case'.6 It added that restrictions on formaldehyde and skin sensitisers, chemicals that can trigger skin allergies, were 'in the final stages of preparation'.6 We found no record of where those plans stand now, so we can't tell you that any nappy-specific limit is in force.
This investigation continues below.
Want the next one in your inbox?
Germany's risk institute also points out that responsibility for meeting safety rules lies first with the manufacturer or distributor.2 So when a pack says 'gentle' or 'dermatologically tested', you are relying mainly on the maker's own checks, and the pack doesn't have to list the scents inside.
What nobody has measured
The safe levels used in the risk assessment all came from studies where the chemicals were swallowed, not put on skin, and for some substances the link between dose and harm was known only from animal studies.13 According to campaigners quoting it, the EU's Risk Assessment Committee also noted that exposure can rise under occlusive conditions, with skin sealed in under the nappy, and that baby rash might enhance absorption.7
For a parent today, that means nobody can tell you how much your baby absorbs, so the sensible course is to remove what is easy to remove and keep skin dry and healthy, since sealed-in, rashy skin is the condition that may let more through.
One kind of study would change our advice: a direct measurement of how much of these chemicals crosses a baby's skin from a nappy, worn the way babies really wear them. If it found far less than France's estimates, the scent advice would stand and the rest could relax; if it found more, the case for EU limits would be hard to argue with.
What to choose
Keep using disposables if they suit you, and start with the habits that cost nothing. Change nappies promptly, give your baby some nappy-free time each day and treat rash quickly: a dry, rash-free bottom is better on every count, including how much might pass through the skin.
Next, skip scented nappies, which are the worse choice: fragrance is added on purpose, and you can avoid it just by reading the pack. Pick a pack or product page that says 'fragrance-free' or 'unscented', and if a nappy smells perfumed when you open it, switch brands next time.
If you want to go further, look for pulp described as 'totally chlorine free' or 'TCF' on the pack or product page, which takes chlorine bleaching out of the picture. Neither label rules out every trace, because some contamination comes from raw materials and the environment, and nothing in the research we read shows any brand to be free of these traces, so we can't name a clean one. We prefer unscented nappies with chlorine-free pulp because they remove what can be removed today without giving up the dryness that protects a baby's skin.
If you use cloth nappies for other reasons, the rule we give for baby clothes applies: plain cotton next to the skin, with no 'stain-resistant' or 'waterproof' finish claim, washed before first use. We have seen no tests comparing cloth and disposable nappies for these traces, so we don't claim cloth is cleaner.
If the page doesn't say, one question to the seller covers both: 'Is the pulp totally chlorine free, and does this nappy contain any fragrance?' Unscented first, chlorine-free pulp if you can find it, and plenty of dry, nappy-free time: those three steps cover what a parent can control today.