Standards & Safety
IP protection rating
How to read both digits of an IP code, the test conditions, and the limits of protection against solids and water.
Written and technically reviewed byElectroDesignForge Engineering Team
View the editorial process📖 Definition
The IP (Ingress Protection) rating, defined by IEC 60529, specifies the level of protection provided by an enclosure against the intrusion of solid objects, dust, and water.
Quick Reference
| Property | Value |
|---|---|
| Standard | IEC 60529 |
| Format | IPXX |
| 1st Digit | Protection against solids |
| 2nd Digit | Protection against water |
| Typical Applications | Electronics, industrial equipment, outdoor devices |
IP Rating Format
IP 6 7
│ │
│ └── Water protection
└──── Solid particle protection
First Digit – Protection Against Solid Objects
| Digit | Protection Level | Test Object | Test Conditions |
|---|---|---|---|
| 0 | No protection | — | No protection against contact or ingress of solid objects. |
| 1 | ≥ 50 mm | Rigid sphere Ø50 mm | The sphere must not fully penetrate the enclosure. Protects against accidental contact with the back of the hand. |
| 2 | ≥ 12.5 mm | Standard finger probe Ø12 mm × 80 mm | The finger probe must not touch hazardous live or moving parts. |
| 3 | ≥ 2.5 mm | Steel rod Ø2.5 mm | Prevents access using tools, thick wires or similar objects. |
| 4 | ≥ 1 mm | Steel wire Ø1 mm | Small wires, screws and insects cannot enter the enclosure. |
| 5 | Dust Protected | Talcum powder | Dust chamber with circulating talcum powder. Partial vacuum up to 20 mbar may be applied. Test duration up to 8 hours. Dust ingress is permitted only if it does not interfere with safe operation. |
| 6 | Dust Tight | Talcum powder | Same test conditions as IP5X, but no dust ingress is permitted after 8 hours of testing under vacuum. |
Second Digit – Protection Against Water
| Digit | Protection Level | Test Conditions | Water Characteristics |
|---|---|---|---|
| 0 | No protection | No water protection. | — |
| 1 | Vertical dripping water | Vertical water drops for 10 minutes. | Rainfall equivalent of 1 mm/min. |
| 2 | Dripping water (15° tilt) | Enclosure tilted 15° in four positions for 2.5 min each (10 min total). | Rainfall equivalent of 3 mm/min. |
| 3 | Spraying water | Water sprayed up to 60° from the vertical for 5 minutes. | Oscillating spray tube or spray nozzle. |
| 4 | Splashing water | Water splashed from every direction for 10 minutes. | Oscillating tube or spray nozzle. |
| 5 | Water jets | Water projected through a 6.3 mm nozzle from every direction for at least 3 minutes at a distance of 2.5–3 m. | Flow rate 12.5 L/min ±5%, pressure approximately 30 kPa. |
| 6 | Powerful water jets | Water projected through a 12.5 mm nozzle from every direction for at least 3 minutes at a distance of 2.5–3 m. | Flow rate 100 L/min ±5%, pressure approximately 100 kPa. |
| 7 | Temporary immersion | Complete immersion in water up to 1 m depth for 30 minutes. | Static fresh water. Lowest point of enclosure at 1 m below surface or highest point 0.15 m below surface. |
| 8 | Continuous immersion | Continuous immersion under conditions specified by the manufacturer, generally deeper than 1 m. | Water depth, pressure and duration are defined by the manufacturer and must exceed IPX7 requirements. |
| 9 / 9K | High-pressure / High-temperature water jets | Water jets applied at 0°, 30°, 60° and 90° for 30 seconds per angle (2 minutes total). | Water temperature 80°C, pressure 80–100 bar, flow rate 14–16 L/min, distance 100–150 mm. |
Most Common IP Ratings
| IP Rating | Dust | Water | Typical Application |
|---|---|---|---|
| IP20 | ✔ Finger protection | ✖ | Indoor electronics |
| IP44 | ✔ | Splash resistant | Wall switches, indoor lighting |
| IP54 | Dust protected | Splash resistant | Electrical cabinets |
| IP55 | Dust protected | Water jets | Industrial control panels |
| IP65 | Dust tight | Water jets | Outdoor equipment |
| IP66 | Dust tight | Powerful water jets | Industrial machinery |
| IP67 | Dust tight | Temporary immersion | Sensors, portable electronics |
| IP68 | Dust tight | Continuous immersion | Underwater devices |
| IP69K | Dust tight | High-pressure cleaning | Food processing, automotive |
Understanding IP Ratings
An enclosure must independently satisfy both protection levels.
For example:
IP54
5 → Dust protected
4 → Splash resistant
This does not mean it can be submerged in water.
Similarly:
IP67
6 → Completely dust tight
7 → Temporary immersion
Although IP67 products survive immersion, they are not necessarily resistant to high-pressure water jets.
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Practical Example
Suppose an outdoor electrical junction box is installed on a building.
Requirements:
- Exposure to rain
- Exposure to dust
- No immersion
Recommended protection:
IP65
This provides:
- Complete protection against dust.
- Protection against water projected by nozzles from any direction.
Bibliography
- IEC 60529 — Degrees of Protection Provided by Enclosures (IP Code)
- ISO 20653 — Road Vehicles – Degrees of Protection (IP Code)
- EN 60529 — European Standard for IP Ratings