Small Parts Choking Hazard Test
Authority: U.S. CPSC 16 CFR Part 1501 (Small Parts Cylinder Test)
US federal law (16 CFR 1501) tests toys and children's articles for kids under 3 using a rigid test cylinder 1.25 inches (31.7 mm) in diameter and 1.00-2.25 inches (25.4-57.1 mm) deep. Any toy, or any part that detaches during use-and-abuse testing, that fits entirely inside the cylinder in any orientation without being compressed fails as a choking hazard.
| Parameter / Specification | Standard Value | Unit |
|---|---|---|
| Test Cylinder Diameter | 1.25 | in (31.7 mm) |
| Test Cylinder Depth | 1.00-2.25 | in (25.4-57.1 mm), angled floor |
| Applies To | Toys/articles intended for children under 3 years | 36 months |
| Fail Condition | Item or any detached part fits entirely within the cylinder, in any orientation, without being compressed | - |
How the Small Parts Cylinder Test Works
The test cylinder is defined in Figure 1 of 16 CFR 1501.4, the CPSC regulation implementing the federal ban on choking-hazard toys for children under 3. It is not a simple straight tube: the opening is 1.25 inches (31.7 mm) in diameter, and the cylinder has an angled floor, so its depth varies from 1.00 inch (25.4 mm) on the shallow side to 2.25 inches (57.1 mm) on the deep side. A toy or article is placed into the cylinder without compressing it; if it fits entirely inside, in any orientation, it fails the test and is classified as a banned hazardous substance under the Federal Hazardous Substances Act.
The test doesn't stop at the intact product. Testers also subject the article to standardized 'use and abuse' procedures -- drops, torque, flexing, and similar stresses meant to simulate a toddler's handling -- and then test any pieces that break loose the same way. A toy too large to be a hazard whole can still fail if a small part can be pulled, twisted, or broken off and then fits inside the cylinder.
Scope and Limits of the Rule
The regulation applies specifically to toys and other articles intended for use by children under 3 years (36 months) of age, based on factors like the manufacturer's stated age labeling, marketing, and whether an item is commonly recognized as meant for that age group. Several everyday categories are explicitly exempt from the test, including books and paper products, balloons, writing materials like crayons, pacifiers, and rattles, each of which is instead covered by its own separate safety standard.
Because the rule targets choking specifically, passing the cylinder test doesn't certify a product as safe in every other respect -- strangulation, entrapment, and other hazards are addressed by separate regulations. And because the standard is built around a specific age group, parents of children under 3 should still treat labels like 'small parts, not for children under 3' as a serious warning rather than a technicality, since the rule exists precisely because items just above this size threshold have caused real choking fatalities.