When it comes to which lighting products to purchase, there's a lot to consider. On top of the many technical specifications, you also need to ensure you understand the many standards and certifications. A few you may see most often are NSF, DLC, and UL. Lighting products that have these designations meets specific criteria. Here's what you need to know.
Standards and certifications comprise a vast number of companies and compliances that serve specific purposes—primarily addressing safety, environmental impact and energy efficiency, and sanitation. These standards are divided into specific categories for each product type and certification type to allow for very specific qualifications related to each product. When this system is being used as intended, it gives consumers, installers, suppliers, and anyone else that may be involved confidence that the product is safe and will work well in their application.
There are a variety of ways a product can be tested for safety and quality before it comes to market. For the US, many products are tested by independent agencies against a set of standards designed to ensure they are safe to install and use as intended. For other products—and sometimes other regions as well—companies self certify products based on compliance with published guidelines.
UL (formerly known as Underwriters Laboratories) is the authority for safety standards in the US when it comes to lighting, electronics, materials, and equipment – among other things. They provide standards and testing procedures that are used to categorize and certify a wide variety of products and components—both by UL itself as well as other certification companies that use UL’s standards such as ETL and CSA. A Certified by UL, UL Listed, UL Classified, or UL Recognized mark means a product has passed all tests related to its intended installation and use.
Each product is assigned a file number that can be referenced to find the type of certification(s) a product has as well. During the certification process, lighting products are also given environmental ratings related to where they are safe to be installed. These are displayed in terms of moisture exposure (dry/damp/wet) and in some cases more specific mounting criteria. It should be noted that there is no direct correlation between UL’s environmental rating system and an IP (ingress protection) rating.
What Is the Difference Between UL Listed and UL Certified? What About Classified?
The ‘UL Listed’ mark is used for a variety of lighting and related products. This mark appears on component pieces or whole lights that are meant to be installed without modification. Examples could be a whole fixture or a ballast compatible bulb. The ‘UL Classified’ mark on the other hand, is used exclusively for retrofit products. For example a bulb with this mark could be installed as a retrofit in a UL certified fixture and—provided it is installed correctly—the fixture would retain its original UL certification. Some products, such as tube lights, can carry both UL Listed and UL Classified marks because they could be installed in a number of different ways.
Certified by UL
The ‘Certified by UL’ mark is relatively new compared to the other UL marks. It can go on a variety of products that may have previously fallen under the ‘UL Listed’ or ‘UL Classified’ marks. It represents the same thing as those marks, it is simply part of a newer, updated system. This mark can mean that the product falls under what would have been a ‘Listed’ category and/or a ‘Classified’ category, so it is important to look over the accompanying documentation and UL file number to understand if the product meets any desired requirements.
Some parts will be listed as ‘UL Recognized’ components. Common products in this category related to lighting include power cords and some power supplies.
ETL (formerly known as Electrical Testing Laboratory) is a division of Intertek that performs very similar functions to UL in terms of test and certification, the main difference being that they are testing to established UL standards for US products rather than using their own standards. In other words, UL Listed products and ETL Listed products certified under the same standard (e.g. UL 1598) will be tested to the same requirements whether ETL are UL are doing the testing. The difference is simply which company the manufacturer is working with and where the eventual product listing will be found.
While CSA (Canadian Standards Association) is less commonly seen in the US, they are essentially a Canadian equivalent to UL. Like UL, they generate their own standards for testing and certification related to the Canadian market. When a UL or ETL product is certified for Canada, they are using CSA’s testing methods and criteria as well, just as CSA can certify products and components for the US using UL’s standards.
Contrary to what is often seen, the US DOT (Department of Transportation) doesn’t certify vehicle related products. They do produce standards which must be followed by vehicles using public roadways in the US. These standards can dictate where a light can be placed on a vehicle, the colors allowed for specific types of lights, and much more. If a light meets these requirements it will typically carry a mark or sticker and/or documentation showing it is DOT compliant.
CE (from the French Conformité Européenne) certification is for products and components that are sold or used in the EU (European Union) and in the UK (United Kingdom) through 2022. Specific directives and standards are tested based on the type of product as is the case with other safety certification types. Unlike most North American certification types, CE can be self-certified and a declaration of conformity from either a testing agency or the manufacturer/seller hold the same weight. It should be noted that CE certification isn’t intended for use outside of Europe.
UKCA (United Kingdom Conformity Assessed) will be the UK equivalent to CE and will work similarly. It will be required for products and components used or sold in the UK from the beginning of 2023. This was specifically created for the UK due to their departure from the EU.
RoHS (Restriction of Hazardous Substances) is another EU based compliance. This directive restricts the amount of lead, cadmium, mercury, and other harmful substances that a product contains. Unlike most other certifications, there is no direct US equivalent to RoHS at a federal level—although California does have a similar state requirement in place. As a result, many products sold in the US still reference this directive to display that products are considered to be safe for people and the environment.
Additional Area and Application Specific
Occasionally, very specialized compliances are developed to address specific concerns. Emergency lighting is a good example of this. NYC Code Compliant emergency lighting requires lights to be brighter than conventional codes in other areas. Municipalities sometimes dictate specific sizing for type or colors for emergency lighting as well. There are no formal marks for this type of compliance, so custom badges are often used to signify that a product meets these standards.
In addition to safety, there are also important certifications related to the efficiency and performance of lights. These types of certifications relate to anything from rebate eligibility to building code compliance.
DLC (DesignLights Consortium) creates continually evolving standards related to lighting efficiency and visual performance. They work with a multitude of other agencies and utility providers to offer rebates for installing/upgrading to newer, more efficient LED lights. Like UL or ETL, they test a representative sample of each light they list and categorize them based on a number of factors with efficacy and longevity being some of the most important criteria. Products that meet the basic criteria are then categorized as being ‘Standard’ or ‘Premium’ based on their overall performance. One of the unique aspects of DLC is a customer facing QPL (Qualified Products List) of publicly available test data for any listed products including an individual ID for each product.
California Specific Regulations
CEC (California Energy Commission) Title 20 and Title 24 both apply to aspects of lighting products. Title 24, Part 6 applies to the efficiency of products based on their use as part of a whole system in a building or structure. Title 20 on the other hand is a set of Appliance Efficiency Regulations consisting of federal and state standards. Products that fall under Title 20 must be approved by the state of California for use and are added to a searchable database.
Sanitation—NSF Compliance for Lighting
NSF international (formerly National Sanitation Foundation) compliance, like many certifications, helps make sure the correct products are used for specialized applications to prevent potential dangers to people and the environment where the lights are installed. In the case of NSF certification for lighting, NSF Standard 2 is the most common type of NSF compliance and deals with aspects related to sanitation—specifically in non-food zones, splash zones, and cold storage areas. This type of certification can be listed through UL, ETL, or even NSF directly. Products listed to NSF standards will generally bear one of the following marks as evidence of its compliance. You can learn more about LED solutions for commercial and industrial applications here.
This type of area is one where there is no direct contact with food or food products under normal circumstances, but there is still a need for protection against contamination to the space or products within the space. This type of area would also normally be outside what would typically be considered a wash-down area. The main criteria for lighting in this type of area revolves around its ability to withstand cleaning, resist the product finish chipping or peeling, and be designed to be able to withstand impact damage with minimal risk of contamination.
Like a non-food zone, this type of area is one where there is no direct contact with food or food products under normal circumstances, but liquids or other materials used in or that are a product of the food processing may come into contact with the fixture. This type of area necessitates a light tested to withstand high pressure wash-downs as that process regularly occurs in this type of area. The light also must be designed in such a manner where it can easily be cleaned during the wash-down process, not allowing food processing related particles or liquids to become stuck to the surface.
Cold Storage Areas
Many food processing operations require refrigeration or below freezing temperatures in some storage and processing areas. Lights must be capable of operating in a wide temperature range and just as in a splash zone, be capable of being effectively cleaned without damage to the light or risk that the light will contaminate food or the area itself.