IP68 means dust-tight (first digit 6) and protected against continuous immersion beyond 1 meter (second digit 8). But the depth and duration are defined by the manufacturer, not the standard. Two products can both carry IP68 and differ by meters of rated depth and hours of test duration.
What makes IP68 different
Every other second digit in IEC 60529 has fixed test conditions. IPX7 is always 1 meter for 30 minutes. IPX5 is always 12.5 liters per minute from a 6.3mm nozzle. IP68 breaks this pattern. The standard says only that the conditions must be more severe than IP67, meaning depth must exceed 1 meter. Everything else is between the manufacturer and the end user.
This makes IP68 the most misunderstood IP rating in product catalogs. Buyers see the badge and assume equivalence. They shouldn't.
Two IP68 products, very different test conditions
| Product type | Rated depth | Rated duration |
|---|---|---|
| Cable junction box (buried) | 1.5 m | 30 min |
| Submersible pump connector | 5 m | Continuous |
How to read an IP68 datasheet
Since the standard doesn't fix the test parameters, the manufacturer must declare them. Look for a line like "IP68: tested at 3m for 4 hours" or "IP68 (2m, continuous)." If the datasheet just says "IP68" with no depth or duration, that's a red flag. Ask the manufacturer for the test report before you spec the product into a submersion application.
An IP68 rating without a stated depth and duration is incomplete. The badge alone tells you the product survives immersion beyond 1 meter, but not how far beyond.
Products that carry IP68
Submersible pump housings and motor casings are the classic IP68 application. The rated depth matches the intended installation depth in wells, tanks, or wet wells.
Underwater luminaires for pools, fountains, and architectural water features carry IP68 with depths typically rated to 2-5 meters. Buried junction boxes and cable splices for direct-burial installations use IP68 to handle waterlogged soil. Industrial connectors for subsea or wet-environment automation (some M12 variants, custom circular connectors) also fall here.
IP68 vs IP67 vs IP69K
People confuse these three. They test completely different things.
| Rating | What it tests | Depth/pressure | Duration |
|---|---|---|---|
| IP67 | Temporary immersion | 1 m (fixed) | 30 min |
| IP68 | Continuous immersion | >1 m (varies) | Varies |
| IP69K | High-pressure washdown | 80-100 bar spray | 30 sec per angle |
IP69K doesn't test immersion at all. A product rated IP69K can survive industrial steam cleaning and still flood if you drop it in a tank. If you need both washdown and submersion protection, you need the combined rating (sometimes written IP6K9K).
Need protection from temporary flooding at ground level: IP67 is sufficient. Need continuous submersion at a known depth: IP68, but confirm the manufacturer's rated depth matches your installation. Need high-pressure steam cleaning: IP69K, and add IP67 or IP68 separately if submersion is also a risk.
IP68 in your product data
When normalizing IP68 entries, the rating code itself is straightforward: IP68, no space. But your product records should also capture the rated depth and duration as separate attributes if the manufacturer provides them. A filter for "IP68" that returns products rated at 1.5m alongside products rated at 10m is technically correct but practically misleading.
Validate IP rating format across your catalog with the IP rating validator. For the full reference of all codes and test conditions, see the IP rating chart.