Decoding IP Ratings: What are IP ratings, and why do they matter?

IP testing

As modern lives evolve to be more dependent on technologies, manufacturers of consumer electronics are continuously finding new features to differentiate themselves from the competition.

High-end electronics being “waterproof” or “water-resistant” has become a norm over the past five years. On the other hand, industrial-grade machines or systems have long been required to be waterproof for operational, regulatory and safety reasons. How does an industry professional distinguish whether certain product features are merely descriptive, or will they truly be resilient under harsh working environments?

Fortunately, a standardized framework was established by the International Electromechanical Commission (IEC) for the usage of these terminologies. This article will help professional engineers understand each term’s definition and how they should incorporate these gradings into product designs.

History of the IP Rating System

The IP rating, also known as the Ingress Protection (IP) rating system, was first established in 1976 by the IEC to standardize how to classify electrical enclosures and mechanical casings against ingresses such as dust and water particles. The details of the IP ratings and corresponding tests can be found in IEC’s Publication 60529, which has undergone steady revisions by IEC’s Technical Committee to accommodate modern industrial applications. The IP rating system is widely adopted by electrical and mechanical engineers, especially in North America, since many consumer products must indicate an IP rating to qualify for UL or CSA’s safety standards.

The standardization paved a way to eliminate the ambiguity of terms such as “water-resistant” or “dustproof,” providing a commonly accepted method to compare sealing levels. As a result, decoding, for example, what IP67 or IP66 stands for, is particularly essential for laboratories or plants that must remain dust-free or moisture-resistant. It helps system integrators and machine builders determine precisely how safe it is to use certain electrical or mechanical parts in specific environments or applications for their clients. Mechanical engineers should also adhere to the IEC 60529 guidelines to design enclosures that guarantee safety and performance, adding values to the products and services.

Decoding the IP Marking

The classification system consists of the letters “IP” followed by two numerals and sometimes one letter. The first numeral represents the degree of protection against solid foreign objects, such as dust or debris, on a scale from 0 (no protection) to 6 (dust-proof). The second digit signifies the degree of protection against water ingress, with a top rating of 9. The third letter is most commonly seen on devices used in food processing plants or car washing systems, where an IP69K certification is required to withstand high-pressure and temperature water jets.

Most industrial-level installations need at least IP54 protection. Systems designed for food processing should have IP55 or even IP69K protection to accommodate high-pressure washdowns at 80 °C. Industrial components are often subjected to constant dust particles and sometimes even rainfalls. It is then vital to fully understand the application’s needs and external conditions in order to select the right integration components. The IP ratings and what each number represents are listed below.




Not protected against ingress of this type


Protection against solid objects larger than 50 mm


Protection against vertically falling water drops


Protection against solid objects larger than 12.5 mm (such as a finger)


Protection against vertically falling water drops when enclosure tilted up to 15°


Protection against solid objects larger than 2.5 mm (such as a screwdriver)


Protection against spraying water


Protection against solid objects larger than 1.0 mm (such as a wire)


Protection against splashing water




Protection against low-pressure water jets


Complete protection against dust and is dust-tight, including a vacuum seal, tested against continuous airflow


Protection against powerful water jets


Protection against full immersion for up to 30 minutes at depths between 15 cm and 100 cm


Protection against continuous immersion at depths specified by the manufacturer. Generally up to 300 cm


Protection against high-pressure, high-temperature jet sprays, washdowns or steam-cleaning procedures

As a general rule, higher numbers indicate more stringent protection from a particular environment. Additional letters attached to the rating also show that this specific product or device offers an extra protection level. However, the rating system was not designed to be mutually inclusive, meaning an IP67 certification does not automatically equate to certificates for grades 1-6. Hence, it is not uncommon for some devices to obtain multiple IP certifications. For example, a device can have IP66 and IP68 certifications, which indicates its protective capabilities against temporary immersion in water and powerful water jets. It is also worth noting that the rating represents how well the product holds up when solid objects or water does enter the product. It does not imply the enclosure is entirely immune to ingress even with the highest rating.

Manufacturers are allowed to self-certify the IP ratings according to the IEC 60529 document’s testing guidelines. However, third-party independent testing agencies are recommended as they offer an objective certification and report. Product designs that pass higher or more IP ratings require significantly more R&D time and effort. However, system integrators and machine builders benefit from procuring the right products with the correct rating to prevent an expensive system failure.

Moving Forward

IEC was founded in 1906 as an international governing body that establishes standards, nomenclature, definitions and ratings for all electrical, electronic and related technologies. To date, the IEC 60529 is still one of the commission’s most prominent publications. Its ongoing effort to include new rating levels reflects the advancement of the industrial revolution. For example, the commission added the 9K rating after the Deutsches Institut für Normung (DIN) first formalized it in Germany. The rating was intended to set protection standards for vehicles or pieces of machinery that needed intensive steam cleaning.

Industry 4.0 is looming on the horizon. As the manufacturing industry transitions into a dynamic and interconnected infrastructure, system engineers must acquaint themselves with the IP rating system to select the suitable system-level components for optimal machine runtime. In fact, unplanned downtime could cost manufacturers as high as $260,000 per hour. While hardware failures and malfunctions are the major contributing factor, humidity comes in sixth, bringing one in ten plants’ production lines to a halt.

Machine vision is the eyes of the robots. The scanners must be vacuum-sealed in a dust and moisture-free enclosure to deliver reliable and accurate scan data for analysis. Robust systems and machines translate to a longer lifespan and a higher return on capital investment. Furthermore, minimized downtime naturally contributes to a company’s financial gains. Broader organization impacts are also foreseeable in that consistent customer service delivery can improve brand image over the long run.

With the compliance of various manufacturing standards, including that of the IP ratings, the automation industry as a whole raised the bar for quality machinery. Over time, we also see evidence of manufacturing’s positive impact on the economy attributable to quality improvement. According to the National Association of Manufacturers, every dollar spent in manufacturing injects $2.74 more to the economy. Therefore, it would make sense for equipment and component manufacturers to invest in product designs with top IP-rating compliance, which could benefit the entire manufacturing value chain.