Please explain the chemical on cartridges?

Switch cartridges are coated in Bitrex, a non-toxic chemical that also happens to be the most bitter substance known to man. The idea was that since the cartridges are so small, they’d be a choking hazard for young children. In theory, the Bitrex is supposed to dissuade kids from keeping the cartridge in their mouth long enough to choke. But then some internet wise guy put a Switch cartridge in his mouth, posted about how nasty it tastes, and now everyone else is trying it to see just how bad it is.