What is the difference between IP67, IP68 and IP69K?

IP67 means temporary immersion to 1 m for 30 minutes. IP68 means continuous immersion under conditions agreed between the maker and the user, usually a stated depth beyond 1 m and a longer duration. IP69K (defined in ISO 20653 and adopted in IEC 60529) means resistance to close-range, high-pressure, high-temperature water jets, around 80 bar at 80 C. They test different things: a product can pass IP69K jetting yet fail IP68 immersion, because pressurised jets and static water pressure stress the enclosure differently.

Is an IP rating a regulatory mark like the CE marking?

No. An IP rating is a manufacturer claim about the enclosure performance, normally substantiated by testing to IEC 60529. It is not a regulatory conformity mark in itself. Some product standards (for luminaires, household appliances, medical or industrial equipment) make a minimum IP rating mandatory for a given use, and in that case the claim is verified inside the safety assessment. But IP alone confers no legal right to place a product on the market.

Does a higher IP number always mean better protection?

Not exactly. The two digits are independent scales, so IP67 is not automatically better than IP54 for every use. IPX7 (immersion) does not by itself guarantee protection against the IPX5 or IPX6 pressurised jets used in washdown environments, which is why some specifications quote a dual rating such as IP66/IP68. Pick the digits that match the real hazards rather than chasing the largest number.

What does the X mean in a rating like IPX7 or IP6X?

The X is a placeholder used when one characteristic has not been tested or is not being declared. IPX7 declares only the liquid protection (immersion) and leaves the solid-particle digit unstated. IP6X declares dust-tight protection against solids and leaves the liquid digit unstated. You substitute the X with a real digit only when the corresponding test has actually been performed.

How is an IP rating tested?

Solids are tested with calibrated probes and objects (a 50 mm sphere down to a 1 mm wire) and, for digits 5 and 6, in a talcum-dust chamber under controlled depression. Liquids are tested with drip boxes, oscillating tubes, spray nozzles, jet nozzles and immersion tanks, each with defined flow rate, pressure, distance and duration set by IEC 60529. The product is normally non-energised during the water test, then inspected for harmful ingress.

What is the IK code and how does it relate to IP?

The IK code of IEC 62262 rates an enclosure resistance to external mechanical impact, from IK00 (no protection) to IK10 (20 joules). It is independent of the IP code: IP describes ingress of solids and liquids, IK describes resistance to knocks and blows. Outdoor and public-area equipment is often specified with both, for example IP66 IK10 for a vandal-resistant outdoor camera housing.

Can I claim IP67 just because my enclosure uses a gasket rated for it?

No. A rating belongs to the finished product as assembled, not to a component. Cable glands, connectors and seals carry their own ratings, but the assembled enclosure must be tested as a whole, because openings, fasteners, breathing membranes and cable entries change the result. A defensible claim rests on a test report against IEC 60529 for the actual product configuration.

Do IP ratings expire or need retesting?

The rating itself does not expire, but it only describes the configuration that was tested. Any design change that affects the enclosure (a new connector, a moved vent, a different gasket, a relocated seam) invalidates the previous evidence for the changed area and should trigger retesting. Production controls and periodic checks keep the claim credible over the product life.

IP and IK ratings: ingress protection explained

Author Hugues Orgitello Last updated 28 May 2026 ~12 min read

Guide · Enclosure ingress and impact ratings

An IP rating tells you what can get into an enclosure, and an IK rating tells you what the enclosure can take from the outside. The IP code is defined by IEC 60529 and uses two characteristic digits, the first for solid objects and dust, the second for water, with optional letters for special cases. The IK code is defined by IEC 62262 and rates resistance to mechanical impact in joules. Both are manufacturer claims, normally backed by accredited testing, not regulatory marks in their own right. This guide explains every digit, how each protection is tested, and how to specify and legitimately claim a rating without over-promising.

What the IP code is, and what it is not

The letters IP stand for International Protection, often read as Ingress Protection. IEC 60529 defines a short code that classifies the degree of protection an enclosure provides to the equipment inside it against two families of hazard: solid foreign objects (including dust) and water. The code also protects people against access to hazardous parts inside the enclosure.

A full code reads like this:

IP   2   3   C   H
│    │   │   │   └─ supplementary letter (optional)
│    │   │   └──── additional letter (optional)
│    │   └──────── second characteristic digit (water)
│    └──────────── first characteristic digit (solids)
└───────────────── the code letters

Two points matter before any detail. First, the IP code describes the enclosure as assembled and tested, not a single seal or gland. Second, an IP rating is not a conformity mark. It is a technical claim about enclosure performance, normally substantiated by a test report against IEC 60529. A product standard may make a minimum IP level mandatory for a use case (a luminaire installed outdoors, a washable appliance, an industrial controller in a wet area), and then the IP claim is verified within the safety assessment. On its own, an IP figure confers no right to place a product on the market and is not part of the CE marking.

The first characteristic digit: solids and dust

The first digit runs from 0 to 6. It does two jobs at once: it states the size of solid object kept out, and it states the degree to which a standardised access probe is kept away from hazardous parts inside. Digits 5 and 6 also describe dust.

Digit	Protection against solid objects	Protection against access to hazardous parts	Test means
0	No protection	No protection	None
1	Objects ≥ 50 mm	Back of the hand	50 mm sphere probe
2	Objects ≥ 12.5 mm	Finger	12 mm jointed test finger, 80 mm long
3	Objects ≥ 2.5 mm	Tool	2.5 mm diameter rod or wire
4	Objects ≥ 1 mm	Wire	1 mm diameter wire
5	Dust-protected (limited ingress, no harmful deposit)	Wire	Dust chamber, talcum powder
6	Dust-tight (no ingress)	Wire	Dust chamber, talcum powder

The distinction between 5 and 6 is important and often misunderstood. Dust-protected (5) allows a limited amount of dust to enter, provided it does not enter in a quantity that interferes with operation or impairs safety. Dust-tight (6) allows no dust ingress at all. Many industrial enclosures only need IP5X, because a sealed circuit area inside the housing tolerates a little dust in the outer cavity.

The second characteristic digit: water

The second digit runs from 0 to 9. Each level is a distinct test, with its own apparatus, water flow, pressure, distance, angle and duration. The key insight is that the higher levels are not a simple superset of the lower ones: a product that passes immersion does not automatically pass pressurised jetting, because the physics differ.

Digit	Protection against water	Test means
0	No protection	None
1	Vertically dripping water	Drip box, 1 mm/min, 10 min
2	Dripping water with the enclosure tilted up to 15 degrees	Drip box, tilted, 4 positions
3	Spraying water up to 60 degrees from vertical	Oscillating tube or spray nozzle
4	Splashing water from any direction	Oscillating tube or spray nozzle, full arc
5	Water jets from a 6.3 mm nozzle, any direction	12.5 l/min, 2.5 to 3 m distance
6	Powerful jets from a 12.5 mm nozzle, any direction	100 l/min, 2.5 to 3 m distance
7	Temporary immersion to 1 m for 30 min	Immersion tank
8	Continuous immersion, conditions agreed maker and user	Immersion, depth and time as specified
9 (IPX9 / IPX9K)	Close-range high-pressure, high-temperature water jets	80 to 100 bar, around 80 C, defined nozzle and angles

A few clarifications that prevent most specification errors:

IPX5 and IPX6 are jets, IPX7 and IPX8 are immersion. They are different threats. A device sealed against immersion (static low pressure) may leak under a 6.3 mm or 12.5 mm jet, and vice versa. Where both matter (food processing, washdown machinery, marine deck equipment) a dual rating such as IP66/IP68 is declared, because a single digit cannot represent two non-nested tests.
IPX8 is open-ended. The depth and duration are agreed between the manufacturer and the user, and IPX8 is generally more severe than IPX7, but the exact conditions must be stated. An IPX8 claim without stated depth and time is incomplete.
IPX9 and IPX9K describe the same family of high-pressure, high-temperature jet test. The 9K designation originates in ISO 20653 for road vehicles and has been incorporated into IEC 60529. It is common on heavy vehicles, agricultural machines and equipment cleaned with industrial pressure washers.

The optional letters

Beyond the two digits, IEC 60529 allows two kinds of letter. They are optional, and most consumer products never use them.

Additional letter (access to hazardous parts)

When the protection against access to hazardous parts is better than the first digit alone would suggest, or when the first digit is replaced by X but access protection still needs to be stated, an additional letter A, B, C or D is added.

Letter	Probe	Meaning
A	50 mm sphere	Protected against access with the back of the hand
B	12 mm test finger	Protected against access with a finger
C	2.5 mm tool	Protected against access with a tool
D	1.0 mm wire	Protected against access with a wire

Supplementary letter (special equipment information)

A second optional letter gives extra information about the equipment or the test conditions.

Letter	Meaning
H	High-voltage apparatus
M	Tested for water ingress with the moving parts of the equipment in motion
S	Tested for water ingress with the moving parts of the equipment stationary
W	Suitable for use under specified weather conditions, with additional protection or treatment

So a code such as IP2XC means: protection against fingers (first digit 2), water not tested or not declared (X), and an explicit tool-access protection (C). The X is a placeholder used whenever a characteristic has not been tested or is not being declared, as in the common partial claims IP6X (dust-tight, water unstated) and IPX7 (immersion, solids unstated).

How IP protection is actually tested

The credibility of any IP claim rests on the test method. IEC 60529 prescribes apparatus and acceptance criteria for each digit, and accredited laboratories work to those exact parameters. The equipment under test is normally checked in its in-service orientation, and for water tests it is typically non-energised, after which the inside is inspected for harmful ingress.

Solids and access probes

The access and solid-object tests use a graded set of probes: a 50 mm sphere, a standardised 12 mm jointed test finger 80 mm long, a 2.5 mm rod and a 1.0 mm wire. Each probe is applied with a defined force and must not touch hazardous live or moving parts and, for the relevant digits, must not enter the enclosure at all.

The dust chamber (digits 5 and 6)

Digits 5 and 6 are tested in a dust chamber filled with fine talcum powder kept in suspension. For category 2 enclosures, a vacuum is applied to draw a controlled depression through the enclosure, simulating the breathing that thermal cycling causes in real service. For IP5X, the test passes if dust does not enter in a quantity that impairs operation or safety; for IP6X, no dust may enter at all.

Drip, spray, jet and immersion apparatus

The water tests escalate through distinct rigs:

Drip box for digits 1 and 2: a perforated tray drips water at a controlled rate, with the sample flat (1) or tilted in four positions (2).
Oscillating tube or hand-held spray nozzle for digits 3 and 4: a semicircular tube of nozzles sprays the sample over a defined arc (60 degrees for 3, full arc for 4) at a set flow rate.
Jet nozzles for digits 5 and 6: a 6.3 mm nozzle at 12.5 l/min (5) or a 12.5 mm nozzle at 100 l/min (6), played over every face from 2.5 to 3 m for a duration scaled to the enclosure surface area.
Immersion tank for digits 7 and 8: the sample is submerged to the specified depth (1 m for 30 minutes for IPX7, agreed conditions for IPX8) and then inspected.
High-pressure jet rig for IPX9 / IPX9K: a fan-pattern nozzle delivers roughly 80 to 100 bar at about 80 C from close range at four defined angles while the sample rotates.

After each water test, acceptance is judged by whether water has entered in a quantity or location that could interfere with operation, reduce creepage and clearance below safe limits, reach live parts, or accumulate harmfully.

The IK code: resistance to mechanical impact

Ingress is only half of robustness. An outdoor luminaire, a public-space camera, a vehicle controller or a wall-mounted panel must also survive knocks, kicks and falling objects. IEC 62262 defines the IK code, a two-digit code IK00 to IK10 that states the impact energy in joules the enclosure withstands without a loss of protection.

IK code	Impact energy (joules)	Equivalent (illustrative)
IK00	No protection (not tested)	-
IK01	0.14 J	200 g mass, 7.5 cm drop
IK02	0.20 J	200 g mass, 10 cm drop
IK03	0.35 J	200 g mass, 17.5 cm drop
IK04	0.50 J	200 g mass, 25 cm drop
IK05	0.70 J	200 g mass, 35 cm drop
IK06	1.0 J	500 g mass, 20 cm drop
IK07	2.0 J	500 g mass, 40 cm drop
IK08	5.0 J	1.7 kg mass, 29.5 cm drop
IK09	10 J	5 kg mass, 20 cm drop
IK10	20 J	5 kg mass, 40 cm drop

The joule values above are the values fixed by IEC 62262; the mass-and-drop equivalents are illustrative ways to deliver that energy. The standard specifies the impact element (a hammer with a defined striking face, typically polyamide), the number and distribution of blows, and the conditioning. After the impacts the enclosure is inspected, and any retained IP rating is re-verified, because a crack or a deformed seal seam can break ingress protection even if the housing looks intact.

The IK code is fully independent of the IP code. A specification often pairs them, for example IP66 IK10 for a vandal-resistant outdoor enclosure, but the two are tested separately and neither implies the other.

How to specify, test and legitimately claim a rating

A defensible rating is built in this order: specify from the real hazards, design and test the actual product, then claim only what was demonstrated.

Specify from the environment, not the marketing brief

Start from the service environment and the cleaning regime, then translate it into digits:

Indoor electronics cabinet, dusty factory floor: IP5X is often enough; full IP6X only if the internal area cannot tolerate any dust.
Outdoor enclosure exposed to rain and hose cleaning: IP65 or IP66 (jets), plus an IK level for impact and vandalism.
Equipment that is occasionally submerged or used in standing water: IP67, or IP68 with a stated depth and time.
Equipment cleaned with industrial pressure washers (vehicles, food machinery): IP69K, frequently combined with IP67 because the threats differ.

Quote a dual rating when both jetting and immersion matter, because one digit cannot encode two non-nested tests.

Test the assembled product

A rating belongs to the finished product as built, not to a gasket, gland or connector. Component ratings are inputs, not the answer. The assembled enclosure must be tested as a whole, because fastener torque, cable entries, breathing membranes, displays, buttons and seams all change the result. Use an accredited laboratory working to ISO/IEC 17025 so the report carries weight in a technical file or a customer audit.

Claim only what was demonstrated

A legitimate IP or IK claim is supported by a test report for the specific configuration. Record the digits actually verified, use X for any characteristic not tested, state the IPX8 depth and duration, and keep the report with the product documentation. Where a product standard makes a minimum rating mandatory, the same evidence feeds the safety assessment and the Declaration of Conformity.

Common mistakes

Claiming IP67 without immersion evidence. A gasket "rated to IP67" is not a tested product. Without an immersion report for the assembled unit, the claim is unsupported and fails the first serious audit.
Confusing IP67, IP68 and IP69K. They test different threats: temporary immersion, continuous immersion, and high-pressure hot jets. Passing one does not grant the others. Vehicle and washdown equipment frequently needs both IP67 and IP69K.
Assuming a higher number is always better. The two digits are independent scales. IPX7 (immersion) does not guarantee protection against IPX5/IPX6 jets, which is why washdown specifications quote IP66/IP68 rather than a single high digit.
Treating dust-protected as dust-tight. IP5X allows limited dust ingress; IP6X allows none. Specifying IP6X "to be safe" can force unnecessary sealing, cost and thermal penalties.
Forgetting impact. Public and outdoor equipment that is sealed (high IP) but fragile (no IK) cracks in service, and the crack then defeats the IP. Pair IP with an appropriate IK level.
Ignoring change control. A rating describes the tested configuration only. A new connector, a moved vent or a different membrane invalidates the previous evidence for that area and should trigger retesting.

Where IP and IK fit in product standards

IP and IK are horizontal classifications that many product standards reference rather than redefine. Household appliances, luminaires, maritime equipment and audio/video/IT equipment each impose a minimum IP level for given installation conditions, and the IP claim is then verified inside that product safety assessment rather than standing alone.

For appliances, the wet-location requirements and the corresponding IP levels sit inside the appliance safety standard: see EN 60335 household appliance safety.
For lighting, the IP rating drives where a luminaire may be installed (damp, wet, exposed) and is central to the luminaire standard: see EN 60598 luminaires and LED safety.
For shipboard and exposed-deck electronics, the enclosure and environmental requirements are set by the maritime standard: see IEC 60945 maritime equipment.
For the general safety framework that IP and IK feed into for ITE, audio and similar equipment, see IEC 62368-1 safety engineering.

Treating IP and IK as inputs to the relevant product standard, rather than as standalone badges, keeps the claim aligned with the actual safety case and with any harmonised standard used for presumption of conformity.

A worked example

Case: outdoor connected sensor on a factory yard, occasionally hosed down.

Environment: rain, dust, periodic cleaning with a low-pressure hose, mounted at hand height where it could be knocked. Translate to digits:

Solids: dusty yard, but the live electronics sit in a sealed inner cavity, so IP6X is chosen for full dust-tightness given the long maintenance interval.
Liquids: rain plus hose cleaning points to jet protection, so IPX6; the unit is not submerged, so IPX7/IPX8 is not claimed.
Impact: hand-height mounting in a busy yard suggests IK08 as a balance of robustness and cost.

Result: a target of IP66 IK08, tested on the assembled product at an ISO/IEC 17025 laboratory, with the report filed against the product safety assessment. The claim is exactly what was demonstrated, no more.