Abrasion as a human sexual practice involves sexual arousal from contact with abrasive substances. This can be person-to-person as in a harsh rubbing of the skin known as a dutch rub or with various substances such as scratchy wool or thistles. Use of harsh abrasives such as sandpaper or steel wool will likely cause lasting injury.
Another form of abrasion play is "birching", where a person is struck or brushed with handfulls of twigs and leaves. Similar activity is done using handfulls of sand.
Abrasion play is generally considered safe as long as the skin is not broken. If the skin is broken, even in tiny areas, the area should be disinfected and protected as with any open wound to prevent infection. Improper care can result in permanent scarring.