IP Rating: What is an IP Rating?

Anyone involved with industrial systems will have heard or used the term ‘IP rating’, but what does the term signify – and how does the IP rating of a product affect what you’re looking for?

IP Ratings Explained

IP rating in an embedded context is associated with a products resistance or susceptibility to the ingress of liquids or particles – think of it as Ingress Protection (although IP actually stands for International Protection)

There are two digits involved within an IP rating. The first digit is associated with solid ingress, ranging from no protection through to protection from large objects, such as human finger intrusion through to total protection from fine dust – rated on a scale of zero to 6.

The second digit or the IP rating refers to liquid ingress, normally water or steam.  Care needs to be exercised here in interpreting the rating.  For example, a panel PC with a rating of IP65 suggests its dust and waterproof but it’s often qualified with “from the front”.  This means that the rear of the unit isn’t sealed and must be fitted into an instrument panel to obtain protection for the rear.

Summary & Overview of IP Ratings

First digit – solid ingress, ranging from zero (no protection) to 6 (dust tight)
Second digit – liquid ingress, ranging from zero (no protection) to 9K (powerful high temperature water jets)

IP Rating	Protection Level	Typical Applications
IP65	Dust tight and protected against water jets	General industrial environments requiring dust and water protection
IP66	Dust tight and protected against powerful water jets	Outdoor, marine, and harsh washdown environments
IP67	Dust tight and protected against temporary water immersion	Applications exposed to rain, spills, or accidental submersion
IP68	Dust tight and protected against continuous immersion	Systems requiring operation underwater or in extreme environments
IP69K	Maximum dust protection with high-pressure, high-temperature water resistance	Food, pharmaceutical, and intensive washdown applications

Your own practical experiences – at home or work

If you ever have cause to remove the cover from a desktop PC that’s been in use in a benign environment e.g. an office or home, you will almost certainly have been greeted by bundles of fluff.

As long as air flow is maintained this may not present a problem, but consider an industrial environment where the dust and fluff may become conductive or corrosive.  Add this to the fact that the system may be controlling heavy equipment – a fast moving conveyor belt or a robot and the potential for operational problems or even break-down becomes clear.

What IP Ratings Mean – and Why Testing Matters

Many manufacturers quote high IP ratings, but achieving them is not always straightforward. An IP6X rating requires complete protection against dust ingress and should always be supported by test results when critical to an application.

In one case, a system designed for IP50 protection failed testing due to fine dust entering the enclosure. A simple gasket and filter modification resolved the issue, highlighting the importance of proper validation.

For fully sealed systems, an IP67 rating provides protection against dust and temporary immersion in water up to 1 metre. Applications exposed to high-pressure steam cleaning may require IP67K protection. Robust designs typically feature sealed screw-in connectors, such as M12 connections, to maintain protection.

Thermal Management and EMC Considerations

Maintaining cooling performance while achieving high IP protection can be challenging. Systems must effectively dissipate heat while preventing dust and water ingress.

Access panels, doors, and inspection points also require careful engineering. Gaskets must provide both environmental sealing and EMC protection, requiring a balance between service access, cooling, shielding, and overall system reliability.