Mattress construction in the American market is constrained by two federal flammability standards. They explain several features that shoppers otherwise attribute to quality or marketing.
Two separate standards apply
One long-standing rule addresses smoldering ignition from a cigarette, testing whether a mattress surface will catch and continue burning from a small heat source.
A later rule addresses open-flame ignition, measuring the rate of heat release when a mattress set is exposed to burners simulating burning bedding.
Both are administered by the Consumer Product Safety Commission, and a mattress sold at retail must comply with each before it can be offered.
Compliance is engineered into the layers
Manufacturers generally meet the open-flame standard with a barrier layer placed between the cover and the interior foam or coils.
The barrier is built from inherently flame-resistant fibers, treated fabrics or knitted socks that char and block oxygen rather than burn through.
Because the barrier sits close to the surface, it influences how a mattress feels, and it adds both cost and weight to every unit produced.
The rules apply to the set, not the piece
Open-flame testing is conducted on the mattress together with its foundation, since a real fire involves both. A prototype passes or fails as a combination.
That is one reason manufacturers specify a matching foundation, and why mixing components can move a set outside the configuration that was tested.
It also shapes warranty language, which frequently conditions coverage on the use of an appropriate support system underneath.
Labels carry required information
The law tag sewn to a mattress records the manufacturer, the materials used and a certification that the unit meets the applicable standards.
Removal of that tag is prohibited for sellers, not for owners, which is the origin of a widely misunderstood warning printed on the tag itself.
Records supporting certification must be retained by the manufacturer, so the tag points back to documented testing rather than standing alone as a claim.
The rules shape the market's price floor
Barrier materials, testing and record keeping add a fixed cost per unit that falls hardest on the least expensive products.
Custom and one-off mattresses face the same requirements, which is part of why unusual sizes cost disproportionately more than their materials suggest.
Imported mattresses must comply as well, and enforcement in this area has centered on units entering the country without valid certification behind them.