Because there are so many different combinations in use, a set of charts will help explain it all.

IP ratings are broken into two numbers. The first number is the level of protection against solid objects — things like fingers, tools, wires, and dust. The second number is the liquid protection rating and is tested using water (no water specifications for things like salinity or TDS are referenced) and not other liquids unless specifically mentioned.

IP ratings are a way to describe the ingress protection of your phone. IP itself stands for International Protection Marking, but you might see it called ingress protection because it fits and describes exactly what it is. Phones like the Galaxy Note 7 are rated with an IP specification (IP68) to tell you how resistant to dust and water they are.

Solid particle protection

Solid IP number How effective is it? IP number How effective is it? 0 Not protected at all against any size particle. 1 Particles larger than 50 mm can not enter in enough quantity to affect the normal operation. 2 Particles larger than 12.5 mm

This is the minimum rating to protect against putting your finger(s) into a thing. 3 Particles larger than 2.5 mm can not enter in enough quantity to affect the normal operation. 4 Particles larger than 1 mm can not enter in enough quantity to affect the normal operation. 5 Dust Protected

Dust must not enter in enough quantity to affect the normal operation. 6 Dust Tight

Dust can't enter, even in a vacuum.

The type of dust used for the last two tests could matter and no specifications or particle sizes are given like they are in the first five tests. If you're working with something like a dry stone saw that creates really fine particles, you might want to assume you're not protected. For everyday use, though, dust is dust.

Liquid ingress protection

Liquid IP number How effective is it? IP number How effective is it? 0 Not protected at all. 1 Protected against dripping water. 2 Protected against dripping water when tilted up to a 15-degree angle from its normal position. 3 Protected against spraying water when tilted up to a 60-degree angle from its normal position. 4 Protected against splashing water at any angle. 5 Protected against water sprayed from a 6.3 mm nozzle at 12.5 Liters/minute and 30 kPa (pressure) from three meters away for three minutes. 6 Protected against water sprayed from a 12.5 mm nozzle at 100 Liters/minute and 100 kPa (pressure) from three meters away for three minutes. 6K Protected against water sprayed from a 6.3 mm nozzle at 75 Liters/minute and 1,000 kPa (pressure) from three meters away for three minutes. 7 Protected against immersion in water up to one meter at normal pressure for 30 minutes. 8 Protected against immersion in water one meter or deeper at specifications detailed by the manufacturer. 9K Protection against water sprayed from high-flow and high-pressure jets at high-temperature

Water volume of 14 to 16 Liters/minute

Water pressure of 80 to 100 bar

Water temperature of 80-degrees Celsius

Distance of 0.10 to 0.15 meters

Ratings of 5, 6, 6K and 9K are pretty extreme protection and something we'll never see on a phone or watch or tablet. I'm pretty sure 6K testing would damage your skin, and 80-degree Celsius liquids are a bit above the comfort level of most of us. For phones and other electronics, the 7 and 8 ratings are more important.

In addition, the IP Code has letter designations for additional protection. Like any K rating, you'll never see these on a cell phone.

Additional protection designation

Letter code What it means Letter code What it means f Oil resistant H High voltage protection M Motion during any testing S No motion during any testing W Weather resistant

Note that these additional ratings aren't mandatory. Their absence doesn't mean your phone (or any other IP rated product) will not survive exposure. It just says that nobody is certifying it.

Most importantly, having an IP rating doesn't mean you can do anything you like with your phone. Phones aren't tested individually and they are mass produced. Your phone might fail if you take it into the pool, even if rated for water resistance. Having the IP rating does mean that the people who made it should be willing to stand behind it for any warranty issues.

We wouldn't use an IP certification as the only reason to buy a phone, but having it certainly can be an added bonus!