IP Ratings in Lighting

An IP rating tells you how well a luminaire is protected against dust, contact with hazardous parts, and water. In lighting design, it is one of the first specifications to check—because the right rating protects not only the fixture, but also the visual result, maintenance budget, and long-term reliability of the installation.

What Does IP Mean?

IP stands for Ingress Protection (sometimes also referred to as International Protection). The rating is defined by the international standard IEC 60529 and is written as two digits, for example IP65 or IP67.

• The first digit describes protection against solid objects, dust, and accidental contact.
• The second digit describes protection against water and moisture.
• A higher number does not automatically mean “better overall”; each digit answers a different question.

For example, an IP65 luminaire is dust-tight and protected against water jets, while an IP20 fixture offers no defined water protection and is generally intended for dry indoor environments.

Understanding the Two Digits

First digit: protection against solids

The first digit ranges from 0 to 6. It indicates how well the enclosure prevents dust, debris, tools, or fingers from reaching internal components and live parts.

For most professional lighting applications, IP5X or IP6X is relevant. IP6X is especially important in dusty environments such as industrial facilities, warehouses, public infrastructure, and outdoor architectural installations.

Second digit: protection against water

The second digit ranges from 0 to 9 (with 9K used in certain applications). It defines the type and intensity of water exposure the enclosure can withstand under standardized test conditions.

This is why IP65, IP66, IP67, and IP68 are not interchangeable. Each rating is designed for a different type of exposure.

Why IP Ratings Matter in Lighting Design

An IP rating is not just a technical label. It directly affects how a lighting concept performs over time.

• Reliability: Dust and moisture are among the main causes of premature luminaire failure, corrosion, and degraded optical performance.
• Safety: The first digit also relates to protection against contact with hazardous parts, which matters in public, industrial, and accessible environments.
• Maintenance: A correctly specified IP rating can reduce cleaning, servicing, and replacement costs.
• Design integrity: In-ground, façade, landscape, and marine environments place very different demands on a fixture.
• Warranty and compliance: Installing a product outside its intended IP conditions can affect performance, safety, and warranty coverage.

Common Questions from Lighting Designers

Is IP65 enough for outdoor lighting?

Often, yes—for standard exposed outdoor installations where the luminaire will encounter rain and water jets but not immersion or high-pressure washing. However, for coastal environments, heavy washdown zones, or highly exposed façades, IP66 may be more appropriate.

Does IP67 mean the light can be used underwater permanently?

No. IP67 refers to temporary immersion under defined test conditions, commonly up to 1 metre for 30 minutes. For permanent underwater use, look for an IP68 rating and verify the manufacturer’s stated depth, duration, and installation requirements.

Is a higher second digit always better?

Not necessarily. IPX7 and IPX8 address immersion, while IPX5 and IPX6 address water jets. A fixture may need jet protection rather than immersion protection, depending on whether it will be pressure-washed, exposed to storms, or installed at ground level.

Does IP rating cover corrosion, UV resistance, or salt spray?

No. The IP code describes ingress protection only. It does not automatically guarantee resistance to UV exposure, salt corrosion, chemicals, extreme temperatures, or mechanical impact. Those properties must be assessed separately through material specifications, coatings, and relevant environmental tests.

How to Choose the Right IP Rating

Start from the real installation environment, not from the highest available number.

1. Identify exposure: Is the fixture indoors, under a canopy, on a façade, in the ground, or submerged?
2. Assess cleaning and maintenance: Will it be washed down, exposed to sprinklers, or cleaned with pressurized equipment?
3. Consider water behaviour: Think about rain, condensation, splashes, jets, standing water, and immersion.
4. Check the full product specification: IP rating, IK rating, materials, temperature range, and installation instructions should be evaluated together.
5. Match the rating to the application: IP65 for general outdoor use, IP66 for powerful jets and harsh exposure, IP67 for temporary immersion, and IP68 only when the manufacturer specifies continuous immersion conditions.

Go Deeper with the Video

For a clearer, more practical explanation of IP ratings in the lighting industry including how to interpret the two digits, avoid common specification mistakes, and choose the right protection level for different projects watch the video embedded in this blog. Vedran breaks down the topic in an accessible way, making it especially useful for lighting designers, specifiers, and anyone involved in selecting luminaires for demanding environments.