I just had a customer bring in a ruggedized handheld terminal, barely six months old, completely dead after what they described as a “brief dip in a puddle.” They were adamant that it was IP68 rated, and therefore, “waterproof.” This isn’t an isolated incident; I’ve seen it countless times with phones, smartwatches, and industrial gear. People hear “IP68” and envision a device impervious to water, ready for deep-sea diving or a spin in the washing machine. It rarely works out that way.
The common approach is to just trust the marketing claim, or maybe glance at the numbers without understanding what they actually represent. That’s a recipe for dead electronics and frustrated users. My method, honed over years of dealing with these failures, is to break down the IP rating into its specific components and then overlay it with the manufacturer’s fine print and, critically, the reality of everyday use. It’s about setting accurate expectations, which ultimately saves money and avoids unnecessary downtime.
Understanding the IP Rating System
The “IP” in an IP rating stands for Ingress Protection, sometimes called International Protection. It’s a standard defined by the International Electrotechnical Commission (IEC) in publication 60529. These ratings classify and rate the degree of protection provided by mechanical casings and electrical enclosures against intrusion from solid objects and water.
The rating always consists of two digits, or sometimes a digit followed by an ‘X’ if one level of protection hasn’t been tested or isn’t relevant.
First Digit: Solid Particle Protection
This number indicates protection against solid objects, including dust. The higher the number, the better the protection.
- 0: No protection.
- 1: Protected against solid objects greater than 50mm (e.g., accidental touch by hands).
- 2: Protected against solid objects greater than 12.5mm (e.g., fingers).
- 3: Protected against solid objects greater than 2.5mm (e.g., tools, thick wires).
- 4: Protected against solid objects greater than 1mm (e.g., most wires, small screws).
- 5: Dust protected. Ingress of dust is not entirely prevented, but it won’t interfere with the satisfactory operation of the equipment.
- 6: Dust tight. No ingress of dust. This is the highest level of solid protection.
Second Digit: Liquid Ingress Protection
This number indicates protection against water and other liquids. Again, a higher number means greater protection.
- 0: No protection.
- 1: Protected against dripping water (vertically falling drops).
- 2: Protected against dripping water when tilted up to 15 degrees.
- 3: Protected against spraying water (up to 60 degrees from vertical).
- 4: Protected against splashing water (from any direction).
- 5: Protected against water jets (from a nozzle, any direction).
- 6: Protected against powerful water jets (e.g., strong waves).
- 7: Protected against immersion in water up to 1 meter for up to 30 minutes. This is where most people stop reading.
- 8: Protected against immersion in water under conditions specified by the manufacturer. This is the critical one for IP68.
What IP68 Water Resistance Actually Means
So, when you see IP68, it means the device is dust tight (the ‘6’) and protected against immersion in water under manufacturer-specified conditions (the ‘8’). The “under conditions specified by the manufacturer” part is absolutely crucial and often overlooked.
Unlike IP67, which is a fixed standard (1 meter, 30 minutes), IP68 doesn’t have a universal depth or time. It simply means “better than IP67.” The manufacturer has to state the specific depth and duration for which their product can withstand immersion. This could be 1.5 meters for 30 minutes, 2 meters for an hour, or something else entirely. If they don’t explicitly state it, you’re flying blind.
Practical Interpretation and Expectations
- Always Check Manufacturer Specs: Don’t just assume. Dig into the device’s manual or product page. Look for the fine print on what “IP68” means for that specific model. Some vendors are very clear, others are vague.
- It’s “Resistant,” Not “Proof”: This is a big one. These devices are built to resist water ingress under controlled conditions, not to be impervious to all liquids, all the time. Think of it as a safety net for accidental spills or brief drops, not a green light for underwater photography sessions unless explicitly marketed and warranted for that purpose.
- Temperature and Chemicals Matter: The IP rating tests are typically done with fresh, ambient temperature water. Saltwater, chlorinated pool water, hot water, or sugary drinks can rapidly degrade seals and connectors, leading to failures even in an “IP68” device.
- Aging and Wear: Seals, gaskets, and port covers degrade over time. A device that was IP68 rated when new might lose a significant portion of that resistance after a year or two of daily use, especially if it experiences temperature fluctuations or physical stress.
- Physical Damage: Even a minor drop or ding can compromise the integrity of the seals, rendering the IP rating meaningless. A hairline crack you can barely see might be enough.
- Charging Ports: Many IP-rated devices still have exposed charging ports (like USB-C). While the device might survive a dunk, charging a wet port can cause short circuits and corrosion. Always ensure ports are completely dry before charging.
Common mistakes
One of the biggest mistakes I see, and frankly, one I made myself early in my career, is advising a client that their IP68-rated device was good for continuous, active use in a harsh environment. I remember a specific instance with a supposedly ruggedized tablet. The client was a marine surveyor, and they wanted to use it on deck, occasionally getting splashed, which was fine. But they also planned on short, accidental dips in saltwater during transfers. Based on the IP68 rating, I assured them it would be “no problem” for those brief saltwater exposures. Well, it was a problem. The device failed spectacularly within a few months. The issue wasn’t the brief submersion itself, but the cumulative effect of constant exposure to corrosive saltwater on the seals and internal components, far beyond what the IP rating tests accounted for. I learned then to never assume “beyond 1 meter” means “impervious to anything.” Always dig into the manufacturer’s specific disclaimers and and consider the actual chemical composition of the liquid and the long-term stress on the seals.
Beyond my own misstep, here are other common traps:
- Ignoring the “X”: An “IPX7” rating means it’s tested for water protection (level 7), but there’s no data for solid object protection. It doesn’t mean “no dust protection”; it just means it hasn’t been tested or rated for it. Don’t assume.
- Believing the “waterproof” hype: Manufacturers love to use “waterproof” in their marketing, but the technical standard is always “water resistant.” There’s a big difference. “Proof” implies invulnerability, “resistant” implies a limited capability.
- Hot or cold shock: Submerging a hot phone into cold water, or vice-versa, can cause seals to contract or expand rapidly, creating microscopic gaps that allow water ingress, even within the rated limits.
- Pressurized water: An IP68 rating is for static pressure (immersion). It does not mean it can withstand high-pressure water jets like those from a power washer, or even strong waves if the device isn’t specifically designed for marine use. The dynamic force can easily overcome the seals.
- User-induced damage: Forgetting to properly close charging port covers or SIM card trays, or using a device with a cracked screen, will entirely negate any IP rating. It’s user error, but a common one.
An IP rating is a guideline for protection under specific, controlled laboratory conditions, not an absolute guarantee against real-world mishaps or prolonged abuse.
