First and foremost it must be decided where in the bathroom the lamp should be placed. Then you have to identify the area/zone (the bathroom is divided into 3 zones).
The different areas in the bathroom require different IP-degree for the lamps. IP-degree is an international classification that describes the density of the lamp and is especially important when buying bathroom lamps.
In area 1 and 2 the requirement is IPX4. In practice that means IP44, and if the lamps are exposed to water jets the recommended IP-degree is IP55. Lamps with IP44 are protected against sprinkling of water and steam and can be used on the outer edge of a shower cubicle or bathtub if they are mounted 0.6 meters from the shower head as a minimum.
Area / Zone 0:
This area covers the bathtub, the shower basin and the lower 10 cm in shower cubicle with closed doors.
Area / Zone 1:
Covers the area above area 0 at a height up to 2.25 meters.
Area / Zone 2:
Covers the area 60 cm from the shower cubicle, shower basin or bathtub edge within a height of 2.25 meters.
Outside the above mentioned zones all lamps must be placed.
IP means: International Protection and applies to the item’s enclosure.
IP is indicated along with 2 digits, (i.e. IP20) to state how safe the item is as regards the ingress of dust, solid objects and water. The first digit always indicates the degree of protection against foreign matters penetrating the product, but at the same time, it indicates a certain minimum degree of protection against contact with hazardous components. The second digit indicates the degree of protection against water penetrating the material.
Yes (except for those with integrated LED) if the size of the light bulb allows it to be fitted in the lamp. It is the physical size and not the Watts in the light bulb that determine whether you can fit it in the lamp when it comes to energy-efficient light bulbs.