What are flame retardants?

It's not one thing — it's four

Lumping all flame retardants together is the single biggest source of confusion, so here are the families that actually matter:

• Brominated flame retardants (the older generation, including PBDEs). These dominated foam from the 1970s. The worst of them were withdrawn in North America around 2004 and listed under an international treaty on persistent pollutants. They break down slowly and build up in the body — infants and toddlers can carry several times the levels adults do.
• Chlorinated "tris" (TDCIPP and TCEP). These replaced some of the brominated ones. One of them, TDCIPP, is listed by California as a cancer-causing chemical; TCEP has been banned in Canada since 2014 for foam products made for young children.
• The newer organophosphate esters (the current replacements). These are now the most common family. They're less studied than the ones they replaced — which is the recurring pattern worth knowing about (more on that below).
• Synergists and barriers. Antimony compounds are added to boost the others. Separately, physical barriers — fiberglass, wool, treated fabrics — do the job without being a chemical added to the foam at all.

That last point sets up the most important fact on this page.

Why are they even in a mattress?

Mattresses have to pass a federal fire-safety test. But here's what most people don't realize: that test does not require any chemicals. It's a performance standard — the mattress has to resist an open flame for a set time — and manufacturers can meet it either by adding flame retardant chemicals to the foam or by wrapping the foam in a flame-resistant barrier, or by using fibers that resist fire on their own, like wool. California's own state science program states plainly that compliance is widely achieved without flame retardant chemicals at all.

In other words, when these chemicals show up in a mattress, it's a manufacturing choice — usually the cheapest one — not a fire-safety necessity. That matters, because it means the goal isn't "remove fire protection." It's "get the fire protection without the chemistry you don't need."

Where they end up

Because most flame retardants are simply blended into the foam rather than chemically bound to it, they migrate out over the product's life — they leach, they abrade into dust, and they slowly evaporate. Household dust becomes the main reservoir, which is why studies that wipe people's hands or measure house dust can predict the levels turning up in their bodies. And at the sleep surface specifically, body heat increases how much comes out of the foam (the same effect covered on our SVOCs page — flame retardants are a type of SVOC, too small to be filtered by any weave and only stopped by being adsorbed).

Flame retardants and children's brain development

This is the part the headlines are about, and it deserves to be stated carefully.

For the older brominated flame retardants (PBDEs), the evidence is genuinely strong — not from one study, but from at least four independent groups of children followed over time, in New York, California, Cincinnati, and Canada, plus a formal pooled analysis. Across them, higher exposure before birth is associated with small reductions in childhood IQ — on the order of a few points per tenfold increase in exposure. That's a real, replicated signal. It's also, importantly, an association drawn from prenatal exposure in observational studies, not proof that a specific product harmed a specific child — and the effect shows up differently in boys and girls in some studies.

For the chlorinated "tris" family, the concern is different: TDCIPP is listed as a carcinogen under California's Proposition 65 and causes cancer in laboratory animals, though no major agency has formally classified it as a human carcinogen. For the newest organophosphate replacements, there's now a large and fast-growing body of research — including several studies of thousands of pregnancies — linking exposure to things like shortened pregnancy and altered neurodevelopment. But those findings are genuinely mixed: they vary by chemical, by timing, and by the child's sex, and some don't replicate. The honest summary is that the concern is real enough to take seriously, but the specifics aren't settled.

And the caveat that governs all of this: these compounds are detected in nearly everyone tested, and detecting a chemical in someone's body is not the same as proving it caused harm. (For a concrete look at how much of this actually reaches kids, two 2025 studies tested children's mattresses and bedrooms directly — here's what they found.)

The firefighter angle

There's one group that carries an unusually high flame-retardant load, and it's the reason this topic is personal for us: firefighters. The evidence here is strong because it's direct — when firefighters were tested before and after fighting controlled fires, the breakdown products of flame retardants rose in their urine afterward, meaning they were absorbing these compounds on the job. Other studies have found firefighters' blood levels of older flame retardants many times higher than the general population, and found the chemicals built up in their gear. Good cleaning habits lower the levels but don't eliminate them.

That's the part of the story that doesn't get told: the flame retardants don't only off-gas from a mattress. They also come home on a body — on gear, skin, and hair — and transfer onto whatever that body sleeps on.

What this does — and doesn't — mean

It means flame retardant chemicals are common in inexpensive foam, that some are well-documented hazards and others are under-studied replacements, that they migrate into the dust and air around us, and that certain people — young children and firefighters among them — carry more than average. It does not mean a given mattress has made a given person ill. We don't make that claim, because the science doesn't support it at that level of specificity. What it supports is sensible caution about reducing exposure you don't need to be carrying.

What you can reasonably do

Look for products labelled flame-retardant-free — they exist, because the fire standard can be met without the chemicals. Be a little wary of vinyl (PVC) covers. And know that a certification only covers what it tests: a common foam certification, for instance, checks the foam for a specific banned list, not the cover, the barrier, or every newer chemical. (We'll have a plain-language guide to the certifications and what each one actually covers.)

Where Embr fits

Here's why this shapes what we're building. The fire standard doesn't require these chemicals — but plenty of mattresses already in people's homes contain them, and they come off the foam under body heat while you sleep, while more arrives on your own body from the day. You can't easily un-buy a mattress. So instead, we're designing a passive capture layer that uses the mattress as a tool: it sits at the surface where the contact happens and adsorbs what reaches it, from the foam below and the body above, then gets removed and replaced on a cycle so the captured load leaves the room rather than building up.

We're not claiming a mattress is making anyone sick, and we're not promising a health outcome. We're saying the sleep surface is where exposure from every source converges for hours a night — and that makes it the sensible place to put a tool that simply intercepts.

This page explains a class of compounds and how exposure works. It is not medical advice. Health statements are kept at the level the evidence supports — "associated with" / "research has linked," not claims that any product causes disease in a person. See our methodology and editorial standards.