IP Ratings Comprehensive Guide: Why IPX4 Isn’t Waterproof
More and more these days when we spend time outside, we want to have our electronic devices with us. It’s not just our smartphone, though. We’ll take our headphones, our Bluetooth speaker, camera and tablet with us too.
The expectation is that our device has some protection from the outside elements like dust, mud, rain, water. But how much protection does it have?
Over the last few years, manufacturers of our favorite electronic device have turned to independent testing to demonstrate how robust their product is.
The results of this testing are reported in terms of their IP rating.
IP? What’s that?
I’ll tell you what it is in the rest of this article and determine how useful it is as a rating system. And answer the question: why isn’t IPX4 waterproof?
Let’s get started.
What is an IP Rating?
An IP rating is derived from the IP Code. It is a code that is variously known as the International Protection Marking, IEC standard 60529 or Ingress Protection Marking.
Ingress. That’s not a frequently used word. It is a useful one-word description though of “the act of going in or entering” or “a means or place of entry”. It is a word that dates to the early 1400s in England and the Latin word “ingressus.”
Enough of the history and etymology.
The IP Code classifies and rates the protection provided by mechanical and electrical casings or enclosures against ingress or intrusion.
The focus on intrusion has three aspects to it:
- The level of protection provided to users for the likes of their hands and fingers.
- How much protection there is from dust, dirt, mud, and any other solid foreign particles.
- How much resistance there is to moisture.
The IP code is published by the International Electrotechnical Commission (IEC). The almost equivalent standard in the US is covered by the National Electrical Manufacturers Association (NEMA) standard, number 250 which defines different electrical enclosures.
For consumer electronic products though it is the IP Code that is used to describe the capability of a product for protection from the elements.
Now that we know what the IP Code is, let’s consider why it’s needed.
Why have an IP Rating System?
In the first instance, the code is about defining the level of safety that applies to the use of electrical and mechanical products. It offers a degree of certainty regarding the amount of protection provided.
From the degree of certainty comes the second aspect. There is a level of consistency to a rating that allows a comparison between similar products. Such objective comparisons can’t be made when vague marketing terms like ‘dustproof’ and ‘waterproof’ are used to describe the level of protection.
The safety and certainty provided by the code come from the two digits of the code.
What do the numbers in an IP Rating mean?
The two digits or numbers in the code are related to the three aspects of intrusion mentioned earlier.
The first digit refers to numbers 1 and 2, i.e., resistance to ingress by the user or from foreign bodies (solid particles).
The second digit refers to number 3, i.e., resistance to ingress by moisture.
There is sometimes a letter that is added after these two digits, but these are rarely if at all, used for consumer electronic products so I won’t cover that possibility.
Now let’s explore what each of the two sets of numbers means to you when you see it on the product specification list.
First Digit (Intrusion Protection)
|Number||Object Size||Example of Protection Provided|
|1||>50 mm.||Any large part of the body but not deliberate contact.|
|2||>12.5 mm.||Accidental finger contact.|
|3||>2.5 mm.||Most tools, wires, screws|
|4||>1 mm.||Fine tools, wires, nails, screws, and larger insects.|
|5||Some Dust.||Partial protection but only to the extent, it doesn’t interfere with the operation of the product.|
|6||No Dust.||Full protection for up to 8 hours.|
Second Digit (Moisture Protection)
|Number||Type of Moisture||Example of Protection Provided|
|0||Any type.||No protection.|
|1||Vertical dripping water.||No harm when an enclosure is in an upright position – equivalent to 1 mm of rainfall per minute.|
|2||Dripping water at 15°.||No harm when an enclosure is tilted at 15° – equivalent to 3 mm of rainfall per minute.|
|3||Water spray at 60°.||No harm with water falling as a spray on an enclosure at any angle up to 60° – the test involved an oscillating fixture and a spray nozzle.|
|4||Splashes of water.||No harm with splashes against an enclosure coming from any direction – the test involved an oscillating fixture and a spray nozzle.|
|5||Jets of water.||No harm from water projected by a nozzle 6.3 mm in size at an enclosure from any direction.|
|6||Powerful jets of water.||No harm from water projected by a nozzle 12.5 mm in size at an enclosure from any direction.|
|7||Immersion up to a depth of 1 m (3.28 feet).||No harm when fully submerged – the test was for 30 minutes.|
|8||Immersion in a depth greater than 1 m (3.28 feet).||No harm from continuous immersion – the test is for longer than 30 minutes as agreed with the manufacturer.|
Note as I mentioned earlier there are ratings with the numbers of 6K and 9K, but you won’t find these mentioned for consumer electronic products.
Ok, so we know what each number represents, let’s put the code together.
How is the IP Code Structured?
The IP code has four digits.
- The first two digits are always “IP.”
- The third digit represents an intrusion protection number in the range of 0-6.
- The fourth digit represents moisture protection numbers in the range of 0-8.
If there is not enough data to assign a protection level, the digit is replaced with the capital letter “X.”
There are no hyphens in the IP code.
Now I’ll take you through examples of IP ratings.
Example IP Ratings
|IP Rating||Test Status||Protection Status|
|IP67||The product has been tested for both intrusion and moisture protection.||It is fully dustproof (6) and can be immersed in water to a depth of 1 m (3.28 feet) for up to 30 minutes (7).|
|IP6X||The product has been tested for intrusion protection but not for moisture protection.||It is fully dustproof (6), but there is insufficient data available to rate the product for moisture protection (X).|
|IPX7||The product has been tested for moisture protection but not for intrusion protection.||There is insufficient data available to rate the product for intrusion protection (X), but it can be immersed in water to a depth of 1 m (3.28 feet) for up to 30 minutes (7).|
|IPX-7||This is an invalid IP Code.|
Now you can see the answer to the question, why isn’t IPX4 waterproof?
With a rating of IPX4 (the 4th digit being for moisture protection), an enclosure can only withstand splashes of water. That offers a little protection but is nowhere near fully waterproof.
If we only had marketing terms like ‘dustproof’ and ‘waterproof’ to describe the protection capability of a product, we wouldn’t know how much proofing there is. The two terms imply complete protection from dust and water, but as we know, marketing involves a high degree of exaggeration.
The IP Code cuts through that exaggeration and provides a standardized assessment of the amount of protection.
So, you know that taking an IPX1, IPX2, or IPX3 rated product near a pool is not a good idea. It’s much safer with an IPX7 or IPX8 rated product.
And if you’re out camping or hiking it’s preferable that the rating is IP67 or IP68, so you know you have complete protection no matter how nasty the weather turns.
With the code, you have the confidence to know what rating you need or know where you can take your device or at least know the risks.
There’ll be no more concerns when you’re out and about. You’ll be free to have a great time.