Don't use a box fan in a bathroom

No, there are no box fans specifically designed for humid environments like bathrooms, and you shouldn’t use one there anyway.

Box fans are built for dry indoor spaces. Stick one in a bathroom and you’re asking for trouble — the motor housing isn’t sealed, so moisture gets in, rusts the blades, shorts the electronics, and turns your fan into a fire hazard real quick. Even ones that claim “all-weather” or “outdoor” are usually just a little more rust-resistant, not rated for direct steam and condensation.

What you actually want is a bathroom exhaust fan (the kind that mounts in the ceiling or wall and vents outside) or a damp-rated or wet-rated utility fan if you need portable airflow. Look for an IP rating — IPX4 or higher means it can handle splashing. But a standard box fan in a bathroom? Hard pass.

Your bathroom needs a fan that can handle steam, not a box fan.