Emery dust can irritate the eyes and should be washed if affected.
Emery is a fine-grained mineral mixture that has historically been used as an abrasive. One common use is in nail files, which are used to gently file down nails and body calluses. It is also embedded in sandpaper and added to a variety of compounds and surfaces to increase traction. This mineral is available in pure form for people who want to make their own abrasive mixes and is also available in a variety of formats for specific uses, such as sandpaper to improve traction on stairs.
The mineral mix used varies. The main ingredient is corundum, an extremely hard mineral, and the mix usually includes a variety of iron-bearing minerals, as well as lodestone. Depending on the mineral mix, emery can be dark gray to almost black in color, with a gritty texture that can be adjusted by grinding.
Historically, emery has been largely produced on the Greek island of Naxos and in Turkey. Since then, other abrasives have replaced it, including blends of synthetics, although there is still some demand for a real deal, especially among woodworkers, who like to have a variety of abrasives to work with when they’re finishing projects.
When emery is sold in strips and emery boards, it is bonded to a smooth backing with an abrasive, and the grit is usually left very fine, so the abrasive action will be relatively soft and smooth. The plate or strip should be discarded after the powder begins to rub off or disappear. Minerals can also be sold as loose powder, allowing people to apply them to sanding and polishing tools so they can finish various craft projects.
Emery is relatively inert, which makes it safe to work with as a general rule, unless something unusual is included in the mineral mix. As you can imagine, the dust can irritate the mucous membranes and the eyes and you should wash your eyes, nose or mouth with water if it gets in any of these areas. If ingested, wash out mouth and drink a glass of water; If someone inhales sandpaper, medical attention is recommended as it can damage the delicate tissues of the lungs.