You can reduce flame retardant chemicals in pajamas by washing them repeatedly, but you probably can’t remove them entirely. Research on treated fabrics shows that the first 10 wash cycles produce the biggest drop in flame retardant levels, with little additional reduction after 20 or 30 washes. The more practical solution, for most parents, is choosing pajamas that were never chemically treated in the first place.
Why Pajamas Have Flame Retardants
Federal flammability standards require children’s sleepwear in sizes 0 through 6X to either pass a flame-resistance test or fit tightly against the body. Loose-fitting pajamas, nightgowns, and robes must meet strict burn-test requirements, and manufacturers historically achieved this by applying chemical treatments to the fabric. Tight-fitting pajamas get an exemption: because snug fabric is far less likely to ignite than loose, flowing material, these garments don’t need chemical treatment at all.
This means there are two entirely different categories of children’s pajamas on the market. One is chemically treated to resist flames. The other relies on a snug cut and skips the chemicals. The label tells you which is which.
How to Tell If Your Pajamas Are Treated
Check the garment’s tags carefully. Untreated, tight-fitting pajamas are required by federal law to carry a label reading “Wear Snug-fitting, Not Flame Resistant” in capital letters on the sizing label at the center back. The hangtag on these garments will say: “For child’s safety, garment should fit snugly. This garment is not flame resistant. Loose-fitting garment is more likely to catch fire.” That yellow-background hangtag with black text is a clear signal that no chemical treatment was applied.
Chemically treated sleepwear, on the other hand, is required to have a permanent care label with instructions for protecting the garment’s flame resistance. If you see language about preserving flame resistance through specific washing or drying methods, that garment has been treated. Some labels explicitly mention the flame retardant treatment, but many simply reference care instructions designed to maintain it.
What Washing Actually Does
Flame retardants applied to fabric surfaces (called topical treatments) do wash out gradually. Testing on treated fabrics found that the oxygen-limiting properties of the treatment, a direct measure of flame resistance, dropped considerably after 10 washes. After that initial decline, additional washing cycles produced only small further reductions. Even after 30 full wash cycles, many treated fabrics still retained meaningful flame resistance, which means the chemicals hadn’t fully left the fabric.
If your goal is to reduce chemical exposure as much as possible through laundering, here’s what the evidence supports:
- Wash before first wear. New garments carry the highest concentration of surface chemicals. Even a single wash removes some of the topical treatment.
- Use hot water. Higher temperatures help break down and release chemical treatments from fibers more effectively than cold washes.
- Wash at least 10 times before regular use. This is where the biggest reduction in flame retardant levels occurs. Subsequent washes help, but the returns diminish sharply.
- Skip fabric softener. Testing has shown that even a single rinse with liquid fabric softener can alter the flammability properties of treated sleepwear. While that means the chemical treatment breaks down, the interaction between softener residue and flame retardant residue on fabric isn’t something you want against a child’s skin.
It’s worth understanding the limits here. Some flame retardants are not just applied to the surface but are built into the fiber itself during manufacturing. Polyester blends marketed as inherently flame resistant have the retardant chemistry woven into the polymer structure. No amount of washing removes those compounds because they are the fabric, not a coating on it.
Why Chemical Flame Retardants Raise Concerns
The worry about flame retardants in sleepwear goes back decades. One of the most well-known cases involved a chemical called tris-BP, which was widely used on children’s pajamas in the 1970s. Research published in the late 1970s confirmed that children absorbed tris-BP directly through their skin while wearing treated sleepwear. A breakdown product of the chemical, 2,3-dibromopropanol, was detected in the urine of children who wore or had recently worn treated pajamas. Tris-BP was later identified as a mutagen and a cancer-causing agent in animal studies, and it was pulled from the market.
Modern flame retardants are different compounds, but the underlying concern persists. Many belong to chemical families classified as endocrine disruptors, meaning they can interfere with hormone signaling. Children are particularly vulnerable because of their smaller body size, developing organ systems, and behaviors like putting hands in their mouths. Research on children in Swedish preschools found that skin contact with surfaces containing flame retardant residues contributed meaningfully to their total chemical exposure, especially when combined with hand-to-mouth activity. For most individual compounds tested, exposure levels fell below established safety thresholds, but when researchers modeled high rates of hand-to-mouth contact alongside exposure from multiple sources, the combined load crossed into potentially concerning territory.
The Easier Alternative: Choosing Untreated Pajamas
Rather than trying to wash chemicals out of treated pajamas, most parents will find it simpler to buy pajamas that were never treated. Tight-fitting children’s sleepwear is exempt from chemical flame-resistance requirements under federal law. These garments are widely available from nearly every major children’s clothing brand and are clearly labeled with the “Not Flame Resistant” language described above.
The key requirement is fit. Tight-fitting pajamas must meet specific maximum dimensions at the chest, waist, seat, upper arm, thigh, wrist, and ankle for each size. This snug fit is itself the safety feature: fabric pressed against skin doesn’t catch air, and without airflow, ignition is far less likely. If you buy snug pajamas and then size up significantly so they fit loosely, you lose that protection without gaining any chemical treatment.
For parents who want to go a step further, certain fabrics are naturally more resistant to ignition than others. Tightly woven cotton and wool both burn more slowly than synthetic blends, and some manufacturers use high-density organic cotton specifically to minimize flammability without any chemical additives. Wool in particular self-extinguishes and doesn’t melt onto skin the way synthetics can, though wool sleepwear for children remains a niche market.
What About Adult Pajamas?
Federal flammability standards for sleepwear apply only to children’s sizes 0 through 14. Adult pajamas are not required to meet these standards and are rarely treated with flame retardant chemicals. If you’re concerned about adult sleepwear, the garment is almost certainly untreated unless it was specifically marketed as flame resistant for industrial or occupational use. The same washing principles apply if you want to reduce any residual fabric treatments: wash before wearing, use warm or hot water, and run several cycles before the first wear.