What IP value is required for vehicle lighting?

In this blog you will read:

• Practical tips for mounting and protecting vehicle lighting
• Which IP value is suitable per sector and application
• Why even IP69K is not always a warranty against moisture
• How to avoid moisture problems

Choosing the right IP value

Choosing the correct IP value for vehicle lighting helps determine how long your lights will last in practice. A practical guide for truck, trailer and work lights.

What is an IP value?

An IP value indicates how well a housing is protected against ingress of dust and water. The abbreviation IP stands for Ingress Protection. Behind this abbreviation there are two digits.

The first digit indicates how well a product is protected against solids, such as dust or dirt.
The second figure indicates how well a product resists moisture, water jets or immersion.

For vehicle lighting, this is important because lights are often used in conditions where dirt, rain, mud and cleaning play a major role. The correct IP class therefore helps to better assess whether a light is suitable for a specific application.

Important to note: an IP value alone is not the only factor determining how long a light will last. A good seal and connector are also essential to ensure that the light actually lasts a long time in practice.

Why IP values are crucial for the life of your fleet

Vehicle lighting is exposed to extreme conditions: water, dust, mud, brine and high-pressure cleaning. The IP value (Ingress Protection) indicates the extent to which a light is protected against these influences. The right IP rating prevents interference, condensation, or even complete failure of your lighting.

The purchase price of a light is only 10% of the total cost; the other 90% is in mounting hours and vehicle downtime in case of failure. A light with an IP value that is too low can fail after only a few weeks due to moisture penetration. Conversely, an IP value that is too high can mean unnecessary costs, especially in interior applications.

Want to know more about the general standards for vehicle lighting? Read our article on ECE R10 (EMC) and ECE R48 (mounting). Take a look at our 24V trailer lighting and cabling for applications requiring IP protection in harsh conditions.

IP67: Submersible - suitable for standard road traffic, provided it is not structurally exposed to high-pressure cleaning or extreme conditions. In harsher environments (such as intensive cleaning or wet off-road conditions), higher protection such as IP68 or IP69K is recommended.

What is the difference between IP67, IP68 and IP69K?

Not every IP class offers the same protection. Especially with vehicle lights, it is important to understand that waterproof does not automatically mean that a light is also suitable for high-pressure cleaning or long-term use in harsh conditions.

• IP67 means that a light is completely dust-proof and can withstand temporary immersion in water.
• IP68 means that a light is dust-proof and can withstand more prolonged immersion, depending on the product specifications.
• IP69K means that a light is dust-proof and can also withstand cleaning with water under high pressure and high temperature.

For many standard applications in vehicle lighting, IP67 is already sufficient. However, if lighting is used intensively in muddy, wet or heavily soiled conditions and is cleaned regularly, IP69K is often the better choice. Read more about IP67 and IP69K in our in-depth articles.

IP69K: High-pressure resistant - essential for agriculture, cleaning, infra and livestock transport.
But note: just an IP Certification does not say it all. Without a ventilation membrane, an IP69K light vacuums when cooled (e.g. after working in the rain), drawing moisture in through even the smallest opening or cable. So IP69K is not a warranty for a condensation-free light.

Which IP class fits which application?

The right IP class depends primarily on the conditions in which the lighting is used. Not every application requires the same degree of protection. For regular truck and semi-trailer lighting, IP67 is usually sufficient, while agricultural and construction machinery that is subject to intensive cleaning requires IP69K. IP68 is a specialist class that becomes relevant when prolonged or deeper water exposure is a requirement. The table below shows at a glance which class suits which application.

IP class	Protection against dust	Protection against water	application
IP classIP67	Dust protection: Fullydust-tight	Protection against water: Withstands temporary immersion to a depth of 1 metre for up to 30 minutes	Applications:Standard off-road use, rear lights, marker lights on truck, trailer and trailers
IP classIP68	Dust protection: Fullydust-tight	Water protection: Resistant tocontinuous submersion at a depth and for a duration specified by the manufacturer (deeper than 1 metre, longer than 30 minutes)	Applications: Specialistapplications where prolonged or deeper exposure to water is a requirement, such as lighting permanently installed underwater or heavily exposed marine applications
IP classIP69K explained: meaning, testing and protection	Dust protection: Fullydust-tight	Protection against water: Resistant to high-pressure water (80–100 bar) and high temperatures (up to 80 °C) during close-range cleaning	Applications: Agricultural machinery, construction machinery, work lights and vehicles that are intensively cleaned with high-pressure washers

Quick selection guide for work lights

• Choose IP67 for standard vehicle lighting that is used outdoors and not subjected to intensive high-pressure cleaning.
• Choose IP69K for lighting on vehicles or machines that work in mud, brine, wet conditions or are regularly thoroughly cleaned.
• Always check the application, because not only the IP value but also sealing, cable entry and pressure compensation determine practical performance.

Minimise moisture and dirt problems in lighting

Moisture and dirt are one of the main causes of lighting malfunction. By choosing lighting with a good IP rating, you are already a long way down the road. However, there are more factors that play a role in preventing future problems.

Sealing of cable entries

Most moisture problems do not originate at the lens, but via the cable. TRALERT® uses moulded cable entries or connectors to prevent moisture ingress. See also our range of cabling and connectors.

Breathable membranes

When a light burns, heat is generated. As soon as the light is switched off or enters a colder environment, it cools down. This creates negative pressure in the housing, which can pull air - and possibly moisture - in through the weakest spots such as cable entries or seals.

A breathable membrane, as used by TRALERT®, allows air to pass through but blocks water and dirt. This prevents pressure build-up and vacuum formation inside the light, preventing condensation from the inside. The light can therefore "breathe" without moisture entering.

What causes condensation in vehicle lights?

Condensation in vehicle lights is caused by temperature differences. When cooling down, negative pressure is created, sucking moisture in through cable entries or seals. Without a breathable membrane, this moisture stays in the housing.

What happens technically in case of moisture problems?

Heat development during operation causes pressure to build up in the light. When the light then cools down (e.g. at night or in wet weather), negative pressure is created. Without a breathable membrane, the light then sucks air - and thus moisture - in through the weakest spot: usually the cable entry or an imperfect seal.

Frequently asked questions on IP values and moisture problems

My IP67 light has condensation. Is it broken or leaking?

Not necessarily. Condensation is often caused by temperature differences. A small amount is normal as long as it disappears again. If the moisture remains visible or shapes droplets, there may be a problem with the seal.

Can I hose down an IP67 light with a pressure washer?

No, an IP67 rating does not withstand the high pressure of a steam cleaner or high-pressure sprayer. For high-pressure cleaning, IP69K is usually the safer choice.

Is a cheap IP69K light as good as a TRALERT® light?

No you don't have to. The IP value says nothing about the long-term quality of the seal. TRALERT® uses UV-resistant housings, high-quality gaskets and smart pressure compensation in many cases. Cheap alternatives fog that durable surface mounting.

Which IP value is suitable for an LED lightbar?

This depends on the circumstances; in the TRALERT® lightbar selection guide, you can read all about making the best choice and see the differences in IP values between the lightbars.

Which IP value is recommended for a beacor bar?

Beacon bars are exposed to a lot of wind, dust and other debris. A good seal is therefore essential to prevent interference or failures in the long term. We therefore recommend choosing a minimum of IP67 for a beacon bar. View all IP67/IP69K LED beacon bars.

How to choose the right IP value?

1. Determine the conditions of use: Indoor, outdoor, cleaning?
2. Check: will the light be exposed to water, mud, steam or brine?
3. Use the table above for sector-specific advice.
4. In doubt? Choose too high rather than too low, but pay attention to price/value.
5. Get advice from TRALERT® for specific applications.

Tips for vehicle builders and fitters

Always mount lights with the cable inlet facing downwards or sideways. Avoid mounting points where water remains. And preferably use connectors with IP67 rating or higher.

Do you require a high IP value for ADR lighting? Read our blog on ADR and work lights too.

External sources: International Electrotechnical Commission