To determine whether an electrical appliance such as a luminaire may be installed in the bathroom you need to check the IP-value of the fixture, the voltage at which it functions and the spot you want to install it.
To ensure the safety, the bathroom is divided into four imaginary zones based on their distance from the tub, the shower or the sink. Depending on the zone in which you wish to install the fixture, different safety requirements in terms of IP-value and voltage apply.
The concerning zones are: zone 0, zone 1, zone 2 and zone 3. Zone 0 requires the highest IP-value, while zone 3 requires the lowest. The image below shows how the different bathroom zones are organized.
Zone 0: minimum IPX7
Zone 0 corresponds to the inside of the tub or the shower. The safety requirements are the strictest here. A lighting fixture you want to install in your tub or shower, must have a minimum IP-value of IPX7 (protected against immersion) and must function on an SELV (Safety Extra Low Voltage).
SELV refers to either 12 V alternating current, or 25 V direct current. It’s advised to let lighting fixtures in zone 0 be installed by a qualified electrician.
Zone 1: minimum IPX4
Zone 1 refers to the zone up to 2.25 meters above the bottom of the tub or the shower. An SELV is required here. The IP-value in zone 1 must be at least IPX4 (protection against water sprays).
Zone 2: minimum IPX4
Zone 2 goes up to 60 cm around the tu band the shower, and in a radius of 60 cm above the sink. SELV is mandatory in this zone. 230 V is permitted, provided that the lighting fixture is located at least 1.60 meters above the ground. It also needs to be connected to a 30 mA differential. The IP-value in zone 2 must be at least IPX4 (protection against water sprays).
Zone 3: minimum IPX1
The rest of the bathroom belongs to zone 3. In zone 3 an IPX1 (protection against vertically falling drops) suffices. An SELV is not compulsory, but recommended. 230 V is permitted if it is connected to a 30 mA differential. It is no longer mandatory that all switches in the bathroom are bipolar, although it is still recommended.
