Is there a relay that can be used in a dusty environment?

If a relay is used in an atmosphere in which dust is generated, dust may enter the relay and become trapped between the contacts, preventing the relay from closing. Also, if conductive objects such as wire chips enter the relay, contact failure or short circuit may occur.
In such a case, take measures against dust or use a plastic-sealed relay.

For more information, see Safty Precautions for All Relays: 1. Selecting Relays.

Even when using a plastic-sealed model, accumulation of dust on a printed circuit board may degrade the insulation of the circuit. It is recommended to take measures to seal the control board.