Safety is a big issue when using a gag during BDSM play because there is a danger of asphyxiation when a person's airways are obstructed. Always make sure that a gag fits the wearer and is not too tight. Never leave a gagged submissive alone. Also, never obstruct the wearer's nose when using a gag. Never use a gag on a person who is ill or is suffering from allergies.
Because a person is prevented from speaking when using a gag, he or she will be unable to utter a safeword during a scene. An alternative to the safeword should be decided on beforehand in this case. A hand signal, such as dropping a handkerchief or clenching a fist, can be used, for instance, as can eye signals, such as a series of blinks. Many BDSM players may also use a series of three grunts in place of a safeword during BDSM play involving gags.