Some products and devices must work in the toughest conditions, which means they must be designed and built to meet certain standards. IP (Ingress Protection) rating standards must be met to ensure products can cope under different circumstances.

The IP rating is a common standard across Europe and other countries outside of North America. It is a rating system that uses two numbers, which each have a specific meaning, to rate parts of a device.

What do the numbers mean on an IP rating?

The first number is a solid particle IP rating, which indicates the how well protected an item is against dust and debris, whilst also clarifying how protected and well-sealed moving parts are in relation to people coming into contact with them.

The second number defines the protection level that the enclosure enjoys from various forms moisture such as drips, submersion, etc. However, this only covers fresh-water moisture and does not guarantee protection from other liquids.

The international IP rating makes it simple to know how protected equipment and products are at an initial glance.  

IP Solids Level Size of object protected against Protects Against
0 None Nothing. Allows in all dust and debris.
1 > 50 mm A large surface of the body, such as a hand (no protection against deliberate access).
2 > 12.5 mm Fingers or similar objects not exceeding 80mm in length.
3 > 2.5 mm Tools, wires, etc., of diameter or thickness greater than 2.5 mm.
4 > 1 mm Wires or other similar solid material of thickness greater than 1mm in diameter.
5 Dust Protected Dust that could interfere with satisfactory operation of equipment.
6 Dust Tight All dust
IP Liquid Level Type of water or liquid Protection
0 None No liquid protection
1 Dripping Vertical dripping on an upright object
2 Dripping at 15° Vertical dripping on an object leaning at 15° from vertical
3 Spraying Spraying up to 60° from vertical
4 Splashing Splashes on an object from any angle
5 Jets from a 6.3mm diameter nozzle Jet sprayed from any angle
6 Powerful jets from a 12.5mm diameter nozzle or heavy seas 100 kPa (14.5 PSI) jets from 3 meters
6k Very powerful jets 1,000 kPa (145 PSI) power jets from 3 meters
7 Immersion to 1 metre Up to 1 metre of immersion for up to 30 minutes
8 Submersion deeper than 1 metre Immersion to a depth specified by the manufacturer (suggests it is airtight)
9k Powerful, high-temperature jets Close-range jets up to 80°C/176°F

At the product design and development stage, understanding IP ratings and the requirements of the product can help a designer to create the best product possible.