Difference Between Water Resistant, Repellent, & Proof

Mallory McGuinness-Hickey August 10, 2023

If you're looking for the highest quality protection from the inside out, contact HZO today.

We all see references to waterproof, water-resistant, and water-repellant devices being thrown around on electronic products and printed circuit boards. The big question is: What’s the difference? There are a lot of articles written on this topic, but we figured we would throw in our two cents as well and take a closer look at the differences between all three terms, with a specific focus on the world of devices.

First of all, let’s start with some quick dictionary definitions of waterproof, water-resistant, and water-repellent, as given by the Oxford English Dictionary:

Water-resistant: able to resist the penetration of water to some degree but not entirely
Water-repellent: not easily penetrated by water, especially as a result of being treated for such a purpose with a surface coating
Waterproof: impervious to water

What Does Water-Resistant Mean?

Water resistance is the lowest level of water protection of the three. If a device is labeled as water-resistant, it means that the device’s construction makes it more difficult for water to get inside of it or possibly that it is coated with a very light substance that helps improve the device’s chances of surviving an encounter with water. Water-resistant qualities are great for products such as watches because they help those products withstand light rain or washing your hands.

What Does Water-Repellent Mean?

Water-repellent coatings are the next step up from water-resistant coatings. Devices labeled as water-repellent have properties that repel water from them, which makes them hydrophobic. Water-repellent devices have a better chance of surviving a watery encounter. Most have thin-film nanotechnology, which can coat the inside and outside of an electronic device. Many companies claim water-repellency, but the term is heavily debated because a durable water-repellent is rare and because of all the questions and unpredictable elements associated with it.

What Methods Can You Use to Make Electronic Components Water-Repellent?

Seals and enclosures can help you make your product resistant to moisture by preventing water from leaking in. These can add bulk and weight to PCBs and products and can become dislodged if a consumer drops a product or bumps into it. Humidity in the Application environment can also seep in. If your project needs slight protection, seals and enclosures could be a good solution.

What Does Waterproof Mean?

Defining “waterproof” is simple, but the concept is more complicated. There is no established industry standard to classify a device as waterproof. The closest thing currently available, as far as a rating scale is concerned, is the Ingress Protection Rating scale (or IP Code). The IP Code assigns items a rating from 0-8 in terms of how effective the device is at keeping water from entering into it, a process called the ingress of water. One major flaw in this rating system: What about companies like us here at HZO who are not concerned about keeping water out of a device to save it from water damage? Our coatings allow water inside devices, but the waterproof material we coat them with protects them from any possible water damage. HZO’s services have a different intention than the effect the IP scale can measure. Still, our coatings help you protect your electronic devices from water damage.

Companies take a measured risk when labeling a product as waterproof. Most consumers assume that waterproofing is a permanent condition. Still, devices exposed to “waterproofing” can face water damage in certain situations.

Using the term waterproof can also be considered a risky move for many companies. This is because "waterproof" usually communicates that this is a permanent condition and that whatever has been ‘waterproofed’ will never fail due to contact with water–no matter the situation.

With all the controversy surrounding the correct use and results associated with these terms, it’s no wonder many people use them incorrectly. Unsurprisingly, the products labeled as water-resistant, water-repellent, or waterproof are often misrepresented due to incorrect labeling. The words almost need new definitions with how far technology has come since these terms were first used. We also need a standard to measure a device’s waterproof qualities and represent the possibilities and kinds of technology like HZO that are commercialized and available to device makers now. This outdated scale can’t measure the power of our coatings.

How Can You Make a PCB Submersible?

HZO Parylene protects PCBs from full submersion for years. Parylene is a conformal coating used to protect sensors, PCBs, and components from water. Parylene has stronger barrier properties than traditional polymer coatings, such as silicone, acrylic, or epoxy.

HZO-Coating-Raspberry-Pi-1

What About Splashproof?

A splashproof product has a limited ability to resist water damage and is not immersible. For example, if you take your splashproof headphones with you on a run, they’ll be safe from sweat or droplets from your water bottle, but they won’t survive falling into a puddle.

Using the IP scale can demonstrate the differences between splashproof vs. waterproof products. Most waterproof electronics have an IP67 rating. A product qualifies as splashproof if it has an IP44 rating.

The scale from splashproof to waterproof includes:

IP44. An IP44 product withstands splashes from any direction, making it splashproof. These products are safe from solid materials larger than 1 millimeter.
IP55. These products resist low-pressure jets from any direction. IP55 products also have some protection against dust.
IP66. An IP66 product can withstand strong jets from any direction and completely protect against dust.
IP67. These products are suited for complete immersion at a depth of 1 meter for 30 minutes. This distinction qualifies them as waterproof. They also have total protection against dust.

An HZO Protected World

Because of the advanced level of protection available for electronics that protect them from water, sweat, other liquids and corrosion, the need for new standards is necessary to raise the bar in the minds of consumers. That’s why HZO is seeking to create an HZO Protected World and asking for people everywhere to help us tell the device makers of the world that we want electronics that have better, more reliable protection. Protection from the Inside Out.