IP Rating Guide
IEC 60529 explained with application mapping.
1. Why it matters
The IP (Ingress Protection) code, defined by IEC 60529, tells you exactly how well a luminaire keeps out solids and water. Two digits carry the whole meaning: the first is protection against solid objects and dust (0-6), the second against water (0-9). Reading it correctly stops you from over-paying for sealing you do not need, or — far worse — installing an indoor-rated fixture where rain or wash-down will kill it.
2. What each digit means
| 2nd digit | Protection against water | Typical use |
|---|---|---|
| 4 | Splashing from any direction | Covered outdoor, bathrooms |
| 5 | Low-pressure jets | Wash-down light duty |
| 6 | Powerful jets | Ship decks, wash-down |
| 7 | Immersion to 1 m, 30 min | In-ground, temporary flood |
| 8 | Continuous immersion (agreed depth) | Fountains, underwater |
3. Choose the rating by real exposure
Match the second digit to what the fixture will actually face, then add margin for cleaning and weather. A common, costly mistake is specifying by the room name rather than the exposure — a "warehouse" high bay over a food line that gets pressure-washed needs IP65/IP66, not the IP20 that "indoor" implies.
- Indoor dry (office, dry warehouse): IP20 is enough.
- Damp/covered outdoor (canopy, eaves): IP54-IP65.
- Exposed outdoor, wash-down, marine: IP65-IP66.
- Submerged (fountain, pool): IP68 with a stated depth.
4. Verify the rating is real and durable
An IP number on a datasheet is a claim; the test report and the design detail are the proof. Ask for the IEC 60529 test report for the exact model, and look at how the seal is achieved — a proper gasket and breather versus a bead of silicone that fails in two seasons. IP68 in particular must state the depth and duration, because "IP68" alone is meaningless without those agreed conditions.
5. Checklist
- Read both digits: dust first, water second
- Specify by real exposure and cleaning method, not the room name
- Require the IEC 60529 test report for the exact model
- For IP68, get the stated depth and duration in writing
- Check the sealing method (gasket + breather) not just the number