Children’s mattresses can emit semivolatile chemicals

Researchers at the University of Toronto have measured various semivolatile chemicals emitting from children’s mattresses, which many kids sleep on for as long as 10 h every day (Environ. Sci. Technol. 2025, DOI: 10.1021/acs.est.5c03560). The compounds include organophosphate flame retardants and phthalates, which have been linked to higher rates of negative health effects, including childhood asthma and endocrine disruption. In a companion study, the researchers detected the same chemicals in the air in some children’s bedrooms, as well as in the air immediately above their mattresses (Environ. Sci. Technol. Lett. 2025, DOI: 10.1021/acs.estlett.5c00051).

While the researchers did not analyze the children’s blood or urine for the chemicals, their exposure is “inevitable,” says environmental chemist Miriam Diamond, who led the study. “This is the first study to actually show that the chemicals are coming out of the mattress and are elevated in that sleeping zone, exposing children at levels even higher than the bedroom air.”

Semivolatile organic compounds are chemicals of interest because they are often formulated into consumer products as solids or liquids, but then over years can slowly escape into the air as gases, Diamond says. There the chemicals could be inhaled or transfer directly onto skin, where they could be dermally absorbed, she says.

Diamond’s team bought 16 new infant mattresses from major North American sellers and analyzed their compositions for 45 semivolatile chemicals. The researchers also measured their emissions in various scenarios, including warmed and weighted to simulate children sleeping. In all, 21 compounds were detected. Five of the mattresses contained alarmingly high levels of flame retardants, at 1–3% of the mattress by mass, and one of those five contained a flame retardant that Canada has already banned.

In parallel, the researchers conducted a home study to measure these chemicals in children’s bedrooms. They distributed small rectangles of silicone rubber that serve as passive samplers to 25 families in Toronto. The samplers were placed hanging in each child’s bedroom and on top of the child’s mattress next to where they sleep. Unsurprisingly, the samplers on the mattress collected higher amounts of the semivolatile targets than those hanging elsewhere in the rooms. This finding suggests that the mattress is a significant source of the chemicals compared with other potential sources, such as carpeting or wall paint, Diamond says.

While acknowledging that the exposure study was limited to just 25 homes in Toronto, toxicologist Jamie DeWitt from Oregon State University says that passive sampling with silicone rubber is a well-established method and that the study paints a realistic picture of the chemical exposure from mattresses. “We can be pretty confident that for many of the compounds evaluated here, they’re also likely to be in the person’s blood,” she says.

But DeWitt, who was not involved in the study, adds that “we don’t know exactly what this means for the health of the child at this point in time.” Making sure that children get enough sleep, healthy food, physical activity, and time outside would help offset some of the negative health risks from chemical exposure, she says. “We do have some power over our health in spite of the chemicals that are in the environment.”

Diamond suggests that manufacturers need to better control the chemicals used in their mattresses. Regulations could also use an update: some of the compounds detected are already banned in other children’s products, such as toys. They should also be banned in mattresses, she says. Her team has approached the health authorities of Canada with their findings.

Because the semivolatile compounds can accumulate on textiles and bedding items, Diamond suggests parents wash and change the bedding frequently, and more importantly, minimize items in the crib. “Declutter,” she says.