[somerandomqaguy]

The term is Intrinsically Safe. It's for equipment that is guaranteed won't be an ignition source, specifically intended for things intended to be operating in confined areas where there's a danger that combustible gases can build up.

[hedgehog]

To reinforce, this is harder to achieve than it might seem. Sparking in switches and buttons and electrostatic discharge both are kind of invisible in normal environments but can be disaster on an oil rig or in an area of a hospital where pure oxygen is flowing. All the paperwork and monitoring to make sure that the design is correct and that the manufacturing stays within spec costs money too.