The ingress protection class (IP class) is defined in the IEC and European standard 60529 and verified through appropriate testing. It consists of the letters “IP” and two digits. The first digit indicates the product’s protection against penetration by dust and foreign objects. This part of the IP code also includes protection against the possibility of a person accessing or touching hazardous parts. It can be a single numeral from 0 to 6, where the digit 0 is used when no protection is provided. The higher the number, the finer the foreign objects or dust that the product can withstand.
The second digit stands for resistance against the ingress of liquids. It can be a single numeral from 0 to 9. Both digits may be replaced with the letter X when insufficient data has been gathered to assign a protection level. For example, IP20 or IP2X are typically the minimum requirements for electrical products for indoor use.
A standard interior luminaire will usually have IP20 ingress protection. This is enough to ensure that no one will get an electrical shock from inserting a finger into an opening in the luminaire. This IP class provides no other specific protection.
IP23 – rainproof
When lighting products require protection against water falling from above – for example, from rainfall – IP23 would be the first choice. The requirement is that there should not be water on any electrical components once testing has been completed. An ingress protection rating of IP23 means that a product is spray-proof for liquids falling from above at an incidence angle of about 60°.
IP44 – splashproof
IP3x/-4x means that a luminaire cannot have openings, into which objects with a diameter of 2.5 mm/1.0 mm could be inserted. The test is carried out with a steel wire with the appropriate diameter and a defined force (3N/1N). IPx4 means that the luminaire must withstand water splashes from all directions. This is normally tested using a spray apparatus. These types of luminaires are not normally manufactured as waterproof, but are instead equipped with a water drainage system that prevents water from reaching electrical parts and also ensures that any water that enters will have a way to escape again.
IP54/IP55 – dust- and water-jet-proof
This IP rating means that dust cannot get into electrical components and cause insulation faults. Luminaires with this IP must be impermeable, so more sealing measures are necessary, and they must be tested in a dust chamber. An IPx5 rating requires resistance to water jets (though not with high pressure). Exposure to higher water pressure and volume demands sealing that is much more secure than just IP54. IPx5 luminaires are tested with a water hose with a 6.5 mm nozzle at a distance of 3 metres with 12.5 litres of water per minute.
IP66 – dust-tight and water-jet-proof
IP6x is the highest classification for mechanical ingress (of objects and/or dust). No ingress of dust is permitted upon completion of the test. The luminaires must be completely sealed, including against negative pressure. Seal pressure must therefore be sufficient to prevent the equalisation of negative pressure. IPx6 indicates protection against a powerful water jet or heavy seawater splashes. These are luminaires that may often be cleaned with a pressure hose or be installed on boats and directly exposed to sea waves. In addition to high seal pressure for protection against dust, mechanical force is applied to ensure that the luminaire cannot be opened by the high pressure or volume of water. This applies to both screen deformation and the function of fastening clips. The luminaires are tested using a fire hose with a 12.5 mm nozzle and 100 litres of water per minute. No water can be detected within the luminaire once the test has been completed.
IP67 – dust- and watertight
This rating ensures the same impermeability to mechanical ingress of objects and/or dust as IP66, but the products should also remain watertight after being immersed at a depth of 1 metre for 30 minutes. The mechanical requirements are the same as for a rating of IP66, but the luminaire must not collapse under negative pressure at a depth of 1 metre. It should be noted that IP67 luminaires may not necessarily pass the test for IP66.
IP68 – continuous immersion
This rating is typically used for underwater lighting in swimming pools and internal water tank lighting.