IP66 rating explained: dust-tight and protected against powerful water jets
Complete dust protection plus high-pressure jets and driven spray.
Want the full system, or to decode any other code? See the IEC 60529 standard explained or the IP rating decoder.
What IP66 protects against
Key facts
- Standard
- IEC 60529 (Ingress Protection code)
- Dust
- 6 = dust-tight, complete protection
- Water
- 6 = powerful jets from any direction
- Jet test
- 12.5 mm nozzle, 100 L/min, about 100 kPa, from 2.5 to 3 m
- Does not cover
- Immersion (IP67/IP68), corrosion, impact
What IP66 protects against
The first digit, 6, means the enclosure is dust-tight. The second digit, 6, means it withstands powerful water jets: the test uses a 12.5 mm nozzle delivering 100 litres per minute from 2.5 to 3 metres. That is a big step up from the low-pressure IP65 jet.
IP66 suits harsh outdoor and industrial settings: marine decks, factory floors, hose-down machinery, coastal enclosures and equipment cleaned with strong sprays. The dust-tight seal also handles heavy dust and sand.
What IP66 does NOT protect against
Like IP65, IP66 is a jet rating, not an immersion rating. Powerful jets and immersion are different tests, so IP66 does not imply IP67 or IP68; where both jets and immersion matter, look for a dual rating such as IP66/IP68.
It also does not cover corrosion, salt water, chemicals or impact. A dust-tight, jet-proof enclosure in a coastal or chemical environment can still corrode, because the rating describes ingress, not material compatibility.
IP65 vs IP66 jet test
| Property | IP65 | IP66 |
|---|---|---|
| Solids | 6 - dust-tight | 6 - dust-tight |
| Water | 5 - low-pressure jets | 6 - powerful jets |
| Nozzle | 6.3 mm | 12.5 mm |
| Flow rate | 12.5 L/min | 100 L/min |
| Immersion | Not covered | Not covered |
IP65 vs IP66
Both ratings are dust-tight, so the only difference is the strength of the water jet. IP65 resists a 6.3 mm nozzle at 12.5 litres per minute (hose level). IP66 resists a 12.5 mm nozzle at 100 litres per minute, roughly eight times the flow, for heavy washdown and driven spray.
Choose IP65 for general outdoor use and rain, and IP66 where equipment faces pressure cleaning, wind-driven spray or marine conditions. Neither is submersion-rated, so for standing water you still need IP67.
Frequently asked questions
Is IP66 waterproof?
What is the difference between IP65 and IP66?
Is IP66 better than IP67?
Can an IP66 enclosure be pressure washed?
Does IP66 protect against corrosion?
Related
Sources: IEC 60529 (IEC Webstore) · IEC: IP ratings. An overview for design reference - verify against the current edition before relying on it for compliance.