What is an IP rating?

An IP rating, which stands for Ingress Protection mark, is a grading system used to indicate the level of protection an electrical or mechanical item provides against unwanted intrusion. The two-digit grading system is commonly applied to the item's enclosure. The IP rating provides users with a clear indication of the item's resistance to various types of intrusion.

The term "intrusion" in the context of an IP rating has three meanings:

1. IP codes signify the level of protection an enclosure offers users (hands, fingers, etc.) from electrical or mechanical parts.

2. The degree of protection an enclosure offers against dust, dirt, and other foreign bodies.

3. Its overall resistance to moisture.

Most regions have standardized IP ratings, but slight variations exist based on geographic location. In the UK, IP codes comply with British standard BS EN 60529:1992. They follow IEC standard 60509:1989 in Europe, and internationally, they conform to EN 60529 certification.

Why have an IP rating system?

A universal IP rating system means that buyers and users can be certain electrical or mechanical goods are safe to use in different environments and applications. Where vague marketing terms such as 'waterproof' do not define exactly how well an item can resist moisture ingress, an IP rating is designed to offer a much more precise assessment. As we delve deeper into this guide, we'll discover that each digit in an IP rating provides specific information about the item's level of protection/resistance.

What does an IP rating measure?

As noted briefly above, IP rating denotes three key metrics:

• Resistance to ingress, accidental or otherwise, by the user

• Resistance to ingress from foreign bodies (dust, dirt, etc.)

• Resistance to moisture ingress

An IP rating will generally consist of two digits, occasionally followed by a letter denoting specific materials, hazards, or testing scenarios.

The following explains what each digit in a standard IP code means:

First digit - protection from foreign body and particulate ingress:

• 0 - (or X - see the section below): Not rated (or no rating supplied) for protection against ingress of this type

• 1 - Protection against solid objects larger than 50mm (accidental hand contact with open palm), but not against deliberate body contact

• 2 - Protection against solid objects larger than 12mm (accidental finger contact)

• 3 - Protection against solid objects larger than 2.5mm (tools and wires)

• 4 - Protection against solid objects larger than 1mm (fine tools and wires, nails, screws, larger insects and other potentially invasive small objects)

• 5 - Partial protection against dust and other particulates, such that any ingress will not damage or impede the satisfactory performance of internal components

• 6 - Full protection against dust and other particulates, including a vacuum seal, tested against continuous airflow

Second digit - protection from moisture ingress:

• 0 - (or X - see the section below): Not rated (or no rating supplied) for protection against ingress of this type

• 1 - Protection against vertically falling droplets, such as condensation, sufficient that no damage or interrupted functioning of components will be incurred when an item is upright

• 2 - Protection against vertically dripping water when the enclosure has been tilted up to 15° off vertical

• 3 - Protection against direct moisture spray at angles up to 60° off vertical

• 4 - Protection against splashing water from any direction, tested for a minimum of 10 minutes with an oscillating spray (limited ingress permitted with no harmful effects)

• 5 - Protection against low-pressure jets (6.3mm) of directed water from any angle (limited ingress permitted with no harmful effects)

• 6 - Protection against powerful jets (12.5mm nozzle) of directed water from any direction

• 7 - Protection against complete immersion for up to 30 minutes at depths between 15cm and 1 metre (limited ingress permitted with no harmful effects)

• 8 - Protection against extended immersion under higher pressure, i.e. greater depths. 

• 9K Protection against high-pressure, high-temperature jet sprays, wash-downs or steam-cleaning procedures

IPX ratings

Sometimes, you might encounter an IP rating of 'IPX7' or 'IP5X' while searching for a product. It's essential to understand the difference between IP and IPX ratings. To put it simply, 'IPX' is not a standalone IP code, but it refers to a situation where a numerical rating has been provided for just one of the two main ingress types, which are foreign body and moisture. The 'X' indicates that no rating has been assigned for the other type. Therefore, if a product has an IPX7 rating, it has a moisture resistance rating of 7, but there's no information about its resistance to foreign body ingress. Conversely, if it has an IP5X rating, the product's resistance to foreign body intrusion has been certified at level 5, but there's no information about its moisture resistance.

Types of IP-rated products

There are many types of IP-rated products available on the market. The standardization of these codes enables customers and users to clearly understand each product's abilities and limitations in different scenarios.

In the following section, we will take a closer look at some IP ratings found on everyday items.

Weatherproof & waterproof IP ratings

People frequently look for a "waterproof" or "weatherproof" rating in everyday products like mobile phones, speakers, kitchen and bathroom fixtures, lighting setups, CCTV enclosures, and more. However, using terms like "waterproof" can be misleading because the purpose of IP ratings is to define the exact parameters of potentially vague marketing claims clearly.

The second digit in an IP code indicates the precise level of protection against moisture ingress under different scenarios. The ratings typically accepted as "waterproof" for most general purposes are IP65, IP66, and IP67. However, it's a misconception that items intended for prolonged outdoor use require the highest numerical IP ratings for moisture resistance. Most rainwater falls relatively close to vertical and under very low pressure, even in windy conditions.

An IPX2 rating protects against dripping water equivalent to 3 mm rainfall per minute at angles up to 15°, while IPX3 indicates resistance to continuous spray at up to 60° from vertical. It's also not entirely accurate to think of IP water resistance ratings as "higher" beyond IPX6. IPX7, IPX8, and IPX9 are codes specifically addressing immersion properties, and items certified at these ratings need not necessarily meet the pressurized water jet resistance criteria denoted by IPX5 and IPX6.

IP rated boxes

IP-rated boxes are an extremely familiar sight in all manner of household and industrial environments used to secure access to delicate or potentially dangerous components or house cable terminations. They can also be used for general storage of essential or hazardous items. For this reason, they'll often be available with a lockable door, giving easy access only to authorized personnel.

As they're often deployed in demanding outdoor environments, wall boxes commonly come in rugged plastic moulding with IP ratings for complete moisture ingress resistance (IP67, indicating full hose-down protection and suitability for some marine applications). Transparent windows are often found on wall boxes of this type, allowing for quick visual checking of internal components and systems.

IP ratings for lights

IP ratings for lights are a crucial area of consideration in both home and industrial design when planning/installing a lighting setup, particularly in bathrooms, kitchens, outdoor areas, and any other spaces likely to be exposed to particulates or moisture ingress from various sources (including weather).

While lighting systems use the same IP rating numbers and definitions as any other enclosure, it's also important to be aware of different 'zones' in a given room or area and how they might impact the IP demands your lights need to meet. This is of particular concern in bathroom applications, as we'll see below.

IP ratings for outdoor lights

IP rating for outdoor lights is crucial to the safety and proper functioning of any unit installed where condensation, rain, or wind-blown foreign bodies might pose a potential risk to circuitry and users alike. This includes accent lighting and soffit spots, safety or task floods, PIR/security sensor lights, and more.

The following are general industry rules of thumb for outdoor lighting, but it's always wise to seek manufacturer or supplier advice for your specific application scenario before installation:

• IPX3 will protect against continuous spray at up to a 60° angle, which is generally considered sufficient in partially enclosed or covered areas.

• IPX4 is more commonly used as a minimum in more exposed spaces.

• If the lights are likely to be cleaned using pressurized jets, they should be rated at IPX5 or above.

• Any lighting intended for immersion (e.g., pond or pool lighting) up to a depth of 1m must be rated at least IPX7, but always check explicitly with the manufacturer before installing any lighting below the surface of the water.

• Immersion at greater depths will require IPX8 and should again be checked explicitly for precise ingress resistance capabilities before installation.

IP ratings for bathrooms

Bathrooms are typically divided into zones for lighting and IP ratings, and each comes with different regulatory specifications and criteria that must be met for safety purposes:

• Zone 0 indicates an area inside a bath or shower (such as tray-level lights in a shower cubicle or jacuzzi-style lighting in a bath). Fittings and enclosures used in this zone must be at least IP67 rated for complete immersion and low-voltage (max 12V).

• Zone 1 indicates an area directly above a bath or shower enclosure to a height of 2.25 meters from the floor. This would include any wall—or ceiling-mounted downlights within the vertical perimeter of a shower enclosure, for example. Although IP45 is technically the minimum resistance required here, IP65 is a much more common standard, and most lighting for shower or bath areas will be rated to at least IP65 by default.

• Zone 2 indicates a 60cm radius around any bath or shower enclosure, making a splash-proof rating of IP44 the minimum requirement. (This is also commonly extended to areas around sinks, where the 60cm measurement is usually taken from the taps themselves.)

• Bear in mind that you'll need to plan for future cleaning in most bathrooms and kitchens, so IP ratings for bathrooms that protect against water jets (IP65) may be necessary, even for lighting installed outside the regulated zones listed above.

Electrical IP ratings

As with all other types of enclosures, IP numbers for electrical applications follow the same universal coding system for clarity and ease of understanding. However, it's even more critical with electrical IP ratings to fully consider the potential exposure types and resistance protection you might need for any electronic components or systems, as ingress from particulates or moisture can often result in damage or increased risk.

If the enclosure is to be placed in any challenging industrial environment, be especially mindful of potential ingress from less obvious sources of moisture or particulates, such as condensation, steam, accumulating dust in harder-to-reach areas, and corrosion or chemical attack.