IP65 vs IP66 vs IP67: What Ingress Ratings Mean for Lighting

IP65, IP66 and IP67 look almost identical on a spec sheet. The last digit is what separates them, and it describes a different water test in each case. This guide explains how the code works and what test sits behind each of the three.

A note on sources: the IP code is defined in the international standard IEC 60529, which the IEC sells rather than publishes free. The definitions and test conditions below come from DMF Lighting's technical bulletin on IP ratings, a lighting manufacturer's summary of that standard.

How the IP code works

IP stands for Ingress Protection. In DMF's summary, "the first numeral refers to the protection against solid objects and is rated from 0 (no protection) to 6 (full protection from ingress of dust). The second numeral rates the enclosure's protection against water and uses a scale from 0 (no protection) to 9 (protection from high pressure, hot water jets from different angles)."

A numeral can also be replaced with an X. DMF describes it as "indicating that there is no data to specify an ingress protection rating for that criterion," with the example that IPX4 "means that solid ingress protection was not tested."

The first digit: all three are dust-tight

IP65, IP66 and IP67 share the same first digit. Level 6 is the top of the solids scale, described by DMF as "Dust tight. No Ingress of dust." The difference between the three is in the second digit.

The second digit: the water test

The test conditions, as DMF's bulletin states them:

• IP65, water jets. Level 5 is "Protected against water jets," tested "using a jet hose nozzle 6.3mm in diameter and a flow rate of 12.5 L/min, from 2.5m to 3m in distance, for a minimum of 3 minutes."
• IP66, powerful water jets. Level 6 is "Protected against powerful water jets," tested with "a jet hose nozzle 12.5mm in diameter and a flow rate of 100 L/min" from the same 2.5 to 3 m distance, for a minimum of 3 minutes. That is eight times the flow of the level 5 test.
• IP67, temporary immersion. Level 7 is "Protected against effects of temporary immersion in water between 15cm and 1m." In the test, the fixture "is submerged to a depth of up to 1m for 30 minutes."

Beyond these, level 8 (IPX8) covers "continuous immersion in water beyond 1m," at a depth and for a period specified for the test.

Reading the rating on a spec sheet

Each rating tells you which test the fixture passed: jets for a 5 or 6, immersion for a 7. The relationships between levels are defined in IEC 60529, which is not reproduced here. If a fixture has to handle more than one kind of exposure, such as powerful jets and possible submersion, confirm with the manufacturer which ratings it was tested to, and look for each one on the spec sheet.

A few pointers from DMF's bulletin:

• DMF describes IP65 fixtures as "appropriate for use in exterior, uncovered applications" that "can withstand direct exposure to weather, rain and the elements."
• Among its own products, DMF lists its M Series Commercial Vandal Trim for exterior applications with frequent exposure to water, noting it "offers IP66 level protection when installed in an appropriate ceiling."
• For fixtures "intended to operate fully submerged in water, such as pool or pond lighting," DMF says they "should be IP-68 rated at a minimum."
• For fixtures that may face frequent pressure washing, DMF points to the top of the scale, IP69.

For where the IP rating sits among the other numbers on a datasheet, see our guide to reading a lighting spec sheet.

IP ratings and UL wet, damp and dry listings

Fixtures can also carry a UL dry, damp or wet location listing. DMF's bulletin says that "in many ways" the two "convey similar information to a consumer regarding a product and its resistance to the elements, however they do differ in a few ways." The key difference, in DMF's words: "In contrast to IP Ratings, which describe how well an enclosure protects its internal components, UL Listings are primarily concerned with consumer safety." DMF suggests the UL levels as "a good starting point to categorize where a fixture may be safely used," with an IP rating giving "more specific information" for harsh environments. Check both on the spec sheet.

Get outdoor-rated fixtures from Rock

Rock Lighting & Electric carries exterior lighting, including the RAB line. Our buying guides for wall packs, floodlights, area and pole lights and DMF downlights cover what to look for. Create a contractor account, request a quote, or tell us about the environment and we will point you to fixtures with the right ratings on the spec sheet.

Frequently asked questions

What does IP65 mean? IP65 is an ingress protection rating under IEC 60529. The 6 means the enclosure is dust-tight, and the 5 means it is protected against water jets. DMF Lighting's summary of the test describes a 6.3 mm nozzle at 12.5 L/min from 2.5 to 3 m for at least 3 minutes.

What is the difference between IP66 and IP67? In DMF Lighting's summary, IP66 means protection against powerful water jets, tested with a 12.5 mm nozzle at 100 L/min, while IP67 means protection against temporary immersion between 15 cm and 1 m, tested by submerging the fixture up to 1 m for 30 minutes. One is a jet test and the other an immersion test.

Does an IP67 fixture also meet IP66? Do not assume it. IP67 reflects an immersion test and IP66 a powerful-jet test. The relationships between levels are defined in IEC 60529, which is not reproduced here, so if a fixture needs both, confirm with the manufacturer which ratings it was tested to and look for each on the spec sheet.

What do the two digits in an IP rating mean? In DMF Lighting's summary of IEC 60529, the first digit rates protection against solid objects from 0 to 6, where 6 means full protection from dust, and the second rates protection against water from 0 to 9. An X in place of a digit indicates there is no data to specify a rating for that category.

What IP rating do outdoor lights need? It depends on the exposure. DMF Lighting describes IP65 fixtures as suited to exterior, uncovered applications with direct exposure to weather and rain, IP68 as the minimum for fixtures intended to operate fully submerged, and points to IP69 for frequent pressure washing. Check the fixture's UL location listing as well.

Is an IP rating the same as a UL wet location listing? No. DMF Lighting's bulletin explains that IP ratings describe how well an enclosure protects its internal components, while UL listings (dry, damp or wet) are primarily concerned with consumer safety. Check both on the spec sheet.

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