Source: https://iec.ch/homepage

When buying a phone, we often rely on marketing terms like "waterproof." However, the actual resistance of your device depends on a precise IP rating (short for Ingress Protection). This rating system, also known in technical literature as the degree of protection provided by enclosures, is defined by the international standard IEC 60529^[1].

What Lies Behind the IP Numbers?

Instead of vague promises, the industry uses this internationally recognized two-digit system to classify the degree of protection an enclosure provides against dust and water:

• First Digit (0–6): Refers to protection against the ingress of "solid foreign objects," such as dust. The highest rating, 6, means the device is completely "dust-tight."
• Second Digit (0–9): Determines the level of protection against water ingress. The scale ranges from basic protection (0) to the highest level (9), which includes protection against high-pressure and high-temperature water jets.

For example, while an IP69 rating represents the absolute pinnacle of protection, the popular IP67 rating guarantees the device is dust-tight but limits liquid protection to temporary immersion in water.

Real-World Limitations of the Standard

It is important to highlight a key distinction: an IP rating defines the device's resistance at the time of testing, but it does not define the overall quality of the phone. How a device reacts if water does get inside depends on the specific brand and model, as well as how long the device can maintain its protective properties.

It is particularly vital to understand that a high IP rating does not necessarily mean the phone is immune to hot, salty, or soapy water. These liquids can corrode and damage the protective seals, leaving the device vulnerable regardless of its official rating.