What goes wrong

A child found it

On this page11

The parts were in an open tray The magnets were the ones that mattered They were stored at floor height The jar had a resting lid Nobody knew how many there were A part came off a finished model The kit was assumed to be an adult product And the physical hazard was never the market question The fix is three decisions And one habit References

The gauge does not care that the hobby is for adults.

The parts were in an open tray

Which is how a bench works and how a spill happens. The cylinder test is the quick way to decide what can live open and what cannot.

The magnets were the ones that mattered

Because the injury is not obstruction. Two magnets, or one magnet and a steel part, attract through the bowel wall and cause a perforation, and the child may be well in between.

They were stored at floor height

The container controls a spill and the shelf height controls who reaches it. Height is the cheaper and more effective of the two.

The jar had a resting lid

A knocked jar with a lid that sits rather than latches empties completely. 19 lug and twist closures and 31 child resistant ones here.

Nobody knew how many there were

A hundred magnets bought and an unknown number present. Counting is the only way to know that two are missing, and two is the number that matters.

A part came off a finished model

Which the abuse testing anticipates: anything that liberates is tested on its own. A finished model on a low shelf is a source of loose parts.

The kit was assumed to be an adult product

Whether something is a children's product is a four-factor test, and the resin jewelry property covers it, including that the packaging is one of the four factors.

And the physical hazard was never the market question

A 2 mm screw behaves identically whoever bought it. The gauges describe a child rather than a customer.

The fix is three decisions

Closed containers for anything that fits the cylinder, magnets separated from ferrous parts, and everything above reaching height. None of it costs anything.

And one habit

Sweep the floor after a session. Every part that ends up somewhere it should not went through a floor first.

References

16 CFR 1501.4, test method: "Place the article, without compressing it, into the cylinder. If the article fits entirely within the cylinder, in any orientation, it fails to comply with the test procedure." Articles are then subjected to the use and abuse testing at 16 CFR 1500.51 and 1500.52, and any liberated component other than paper, fabric, yarn, fuzz, elastic and string is tested in the cylinder individually. The cylinder's dimensions are given in Figure 1 of the section rather than in its text. law.cornell.edu

16 CFR 1262.3, safety standard for magnets: "Each loose or separable magnet in a subject magnet product that fits entirely within the cylinder described in 16 CFR 1501.4 must have a flux index of less than 50 kG(2) mm(2)", tested in accordance with the method described in 16 CFR 1262.4. law.cornell.edu

The Davis Pack Supply catalog, measured 19 October 2026. The model parts and paint shelf is 1,136 rows: 646 containers and 490 closures. 5 mL to 2,000 mL with a median of 118; 25 containers at 15 mL or under, 84 at 30 or under, 183 at 60 or under, 336 at 120 or under, 522 at 250 or under. 351 PET, 117 glass, 100 HDPE, 78 PP. 376 bottles, 255 jars, 13 tubs and pails, 2 tubes. 175 clear, 141 white, 101 amber, 61 blue, 60 natural, 47 black. Closures: 288 continuous thread, 32 disc top, 31 child resistant, 26 spouted, 22 dome lids, 19 lug and twist, 14 phenolic, 13 spice caps, 11 liners and sealing discs, 10 flip top.

Written from 16 CFR 1501.4 and 16 CFR 1262, and from the catalog as it stood on 19 October 2026. No cylinder dimensions appear anywhere in this property, because the rule gives them in a figure rather than in its text. Whether a particular part or magnet passes either test is a determination about that article; we sell the container it is kept in. Whether a kit is a children's product is the four-factor test covered in the resin jewelry property.