Short answer
Most mattresses are a stack of layers: a ticking cover, sometimes a fire barrier, comfort layers of foam, latex, fiber or wool, and a support core of coils, foam or latex. Each material has its own chemistry. Foam is made from a polyol and an isocyanate, latex is vulcanized rubber, wool is a scaled protein fiber and coils are steel. That chemistry decides how each one ages and what care it tolerates.
By Matthew Brunken · Updated October 5, 2026 · Last reviewed October 5, 2026 · Sources · Editorial standards
A mattress looks like one object, but it's a stack of different materials, each with its own chemistry. Under the cover fabric there may be a fire barrier, then comfort layers of polyurethane foam, memory foam, latex, fiber or wool, and below them a support core of coils, foam or latex. Knowing what each material is made of explains why it feels the way it does, how it ages and what kind of care it can take.
This hub is general information about mattress materials, not medical advice. For health questions, ask a doctor.
Why materials, and why now
The earlier hubs in this Knowledge Center are about cleaning: methods, compatibility, accidents, allergens, moisture, decisions and, in the seventh hub, the chemistry of mattress stains. They keep running into the same question, which is what the mattress is made of. Memory foam behaves differently from latex, wool from polyester, a coil core from a foam core. This hub answers that question directly, so the cleaning pages can link here instead of repeating it.
We stick to what the materials are and how they behave. Whether a particular material tolerates a particular cleaning method, maker by maker, belongs to the compatibility hub. How water and heat move through a mattress belongs to Hub 5, starting with why construction matters for cleaning.
The layers, as the law defines them
The clearest vocabulary for the layers comes from federal flammability law. 16 CFR 1633 splits a mattress into three zones: the ticking on the outside, the core that does the supporting, and the upholstery material in between. Those legal terms are more precise than marketing names like "comfort system," so we use them throughout, especially in the ticking article and the law tag article.
Foam is chemistry, not just padding
Most mattress foam is flexible polyurethane, made by reacting a polyol and an isocyanate with water, as the Polyurethane Foam Association explains. The same basic chemistry makes soft and firm foams; the density and firmness article explains why the PFA insists density and firmness are independent. Memory foam is a viscoelastic version that the PFA says softens with warmth and humidity, covered in why memory foam softens with body heat. And foam ages: a foam maker's information sheet explains why most foam yellows over time, in why mattress foam turns yellow.
Other materials, other rules
Latex foam is rubber, not polyurethane. It's made by the Dunlop or Talalay process, and researchers such as Sukkaneewat and Utara describe how the two differ. Cooling layers rely on phase-change materials, heat capacity or airflow, and the evidence behind each is narrower than marketing suggests. Wool is a protein fiber with surface scales, and Woolwise's textile notes explain why water and agitation can felt it. Coils are steel, and OpenStax Chemistry explains the basics of rust; a spring maker's descriptions explain the coil types.
Rules that shape what's inside
Some layers exist because of regulation. Mattresses must pass a cigarette test under 16 CFR 1632 and an open-flame test under 16 CFR 1633, and makers choose how to comply. CertiPUR-US says some use fiberglass barrier fabrics, which is why the fire barrier article explains why not to open a cover. Labeling rules also leave gaps: the FTC lists mattress outer coverings among items not covered by the Textile Act. And new foam off-gasses, which the EPA describes as VOCs emitted as gases from solids.
How we handle evidence here
Our sources are the federal regulations themselves, peer-reviewed studies, university and government references, the foam industry's own technical bulletins and, for coils, a spring manufacturer's product descriptions. Industry and manufacturer sources are named as such. Studies are cited for what they tested: a crib-mattress emissions study isn't an adult-bed study, and a bench test with scaled foam samples isn't a night's sleep. Where we couldn't find a source, we say so in each article's "What we don't know" list instead of guessing.
Sleep Sanitation's position
This section is our view. Material knowledge is why we ask what a mattress is made of before we start. We clean through the ticking and never open a cover. Organic cleaning methods are our default, with enzyme treatment for urine and organic odor, and our Italian-made Vapor Clean machines let us keep moisture low for foam, latex and wool alike. We use "sanitize" in the sense set out in the compatibility hub's entry on the CDC's cleaning and sanitizing terms, and we make no disinfection claim. That approach is our own reasoning, not a manufacturer exemption; your care label and warranty terms govern, so check your warranty terms before you book. The first mattress is $249, and the pricing page lists the rest.
How to use this hub
If you know what your mattress is made of, open that material's article. If you don't, start with how to read a mattress law tag and the ticking article. If you're curious about a smell from a new mattress, read off-gassing and CertiPUR-US. Then check the material's page in the compatibility hub before any cleaning.
What we don't know
- What's inside a specific mattress. Makers aren't required to list cover fibers, barrier materials or foam formulas on the label.
- How lab findings about foams, latex and cooling materials carry over to finished, branded mattresses, which combine many layers.
- How long each material lasts in typical home use. The sources describe how materials change, not standard lifespans.
Changelog
- 5 October 2026: First published. Sources accessed on this date.