Here’s what “water resistant” and “water proof” really mean
“Water proof” and “water resistant” mean the same thing, right? Apparently that’s what Archos CEO Loic Poirier thought — he was wrong.
Poirier was happily showing off his new phone — a Quechua — which is advertised to French hikers and mountain bikers. He tossed it on the floor. No problem! Then, with cameras rolling, he found a glass jar, dropped the phone in, and started to fill it up with water. The phone is rated at IP54 and advertised as being designed to “withstand the most demanding outdoor conditions”. When Poirier tried to turn the phone on, while still submerged, he got no response. He pulled it out of the jar, water dripping from its screen, but it wouldn’t turn on. That’s when the video signal was cut.
What happened? Simply put, IP54 doesn’t mean “water proof”.
What’s the difference?
To start with, even Archos knew that the Quechua wasn’t “water proof”, but apparently its CEO didn’t get the memo. From its website:
The Quechua 5″ Phone complies with the IP54 standard. Developed to withstand the most demanding outdoor conditions. It is designed to withstand splattering with water from all directions as well the harmful effects of dust and sand.
In his defense, hardly anything is “water proof”. Many devices indicate their level of “water resistance” in ATMs — atmospheres. The original Pebble smartwatch, for example, is water resistant to 5 ATM — 50 meters or 165 feet. A device with a 5 ATM rating is suitable for showering or swimming in shallow water — or dunking in a glass jar while the cameras are rolling.
There’s another, more comprehensive standard than “atmospheres”, but it’s not quite as easy to understand. Depending on who you ask, the “IP Code” either stands for an object’s Ingress Protection Rating or International Protection Rating. Regardless of what the letters stand for, an object’s IP “classifies and rates the degree of protection provided against the intrusion” from foreign objects like dust and water, and is a standard published by the International Electrotechnical Commission (IEC).
The foreign objects we’re talking about don’t necessarily have to be small. For example, IP22 might be used to describe an electrical socket that is “protected” against people sticking their fingers into it, and won’t “become damaged or unsafe” if it becomes exposed to “vertically or nearly vertically dripping water”. IP22 outlines the “typical minimum requirements for the design of electrical accessories for indoor use”.
Bringing the conversation back to smartphones, Sony’s Xperia Z Ultra is rated at IP58 which signifies that it is “dust resistant” and “water resistant”. According to Sony, not the IP standard, the phone can be immersed in 1.5 meters of freshwater for up to 30 minutes — something Poirier probably wishes his phone could do. Again, his phone is rated at IP54 compared to Sony’s IP58, so we can’t blame him for being confused — he was only off by 4, right?
Breaking the code
The first number after “IP” indicates the size of the foreign object from which the rated item is protected.
- 0: no protection against contact and ingress of objects
- 1: greater than 50mm, including any large surface of the body (i.e., the back of a hand), but no protection against deliberate contact with a body part (i.e., poking your finger where it doesn’t belong)
- 2: greater than 12.5mm; protection against fingers and objects of similar size
- 3: greater than 2.5 mm; protection against tools, thick wires, and objects of similar size
- 4: greater than 1 mm; protection against most wires, screws, and objects of similar size
- 5: protected against some dust; ingress of dust is not entirely prevented, but a lot of dust cannot enter, and that which does must not interfere with the satisfactory operation of the item
- 6: no ingress of dust
The second number (and possibly an additional letter) after “IP” indicates the level of protection against harmful ingress of water.
- 0: no protection
- 1: vertically falling drops of water cannot cause any harmful effects (light rain)
- 2: dripping water cannot cause any harmful effects when the enclosure is tilted at an angle up to 15° from its normal position (moderate rain)
- 3: water falling as a spray at any angle up to 60° from the vertical shall have no harmful effects (spraying water)
- 4: water splashing against the enclosure from any direction shall have no harmful effects
- 5: water projected by a nozzle against the enclosure from any direction shall have no harmful effects (water jets)
- 6: water projected in powerful jets against the enclosure from any direction shall have no harmful effects (powerful water jets)
- 6K: water projected in powerful jets against the enclosure from any direction, under elevated pressure, shall have no harmful effects (powerful water jets with increased pressure)
- 7: ingress of water in a harmful quantity shall not be possible when the enclosure is immersed in water (immersion up to 1m)
- 8: the equipment is suitable for continuous immersion in water (immersion beyond 1m)
- 9K: protected against close-range, high pressure, high temperature spray (powerful, high temperature water jets)
Each of these ratings has a specific test associated with it which includes depth, pressure, and duration, to name a few.
Putting it all together
Now that you’ve seen it all laid out, what looked like fairly similar ratings of IP54 and IP58 now are obviously very different.
- The Quechua was protected against some dust and water splashing against it.
- The Xperia Z Ultra was protected against some dust and being continuously immersed in water.
Ultimately, there is no such thing as “water proof”, just varying degrees of “water resistance”. What most people would consider “water proof” would be at least an IP56, but IP57 and IP58 would be even better for what Mr. Poirier was trying to do.