Original synthesis to sit alongside the encyclopedia article below. Not part of Wikipedia; verify facts on Wikipedia when precision matters.
UL (Underwriters Laboratories) is an independent, non-profit global safety science organization headquartered in Northbrook, Illinois, U.S. It is one of the most recognized safety certification and standard-setting bodies in the world, dedicated to mitigating risks of harm to human life and property across consumer products, industrial systems, construction materials and emerging technology sectors.
Key moments
1894Founded as the Underwriters Electrical Bureau by the U.S. National Board of Fire Underwriters to test electrical devices for fire risk
1901Officially renamed to Underwriters Laboratories Inc. and expanded service scope beyond electrical fire safety
1916Became fully operationally independent from insurance industry funding sources
2012Restructured to form UL LLC for certification operations and an independent UL Standards & Engagement division dedicated to neutral standard development
De Facto Mandatory Market Access Status
While UL standards are formally voluntary under U.S. federal regulation, the organization's century-long accumulated public credibility has turned its certification into a de facto requirement for products entering the North American market. Most major North American retailers, property insurance carriers and local municipal procurement programs require valid UL certification as a precondition for stocking or purchasing products, creating a widely accepted implicit technical threshold for global manufacturers seeking to enter the region.
Public Safety Function Beyond Commercial Testing
Beyond revenue-generating product certification services, UL runs a portfolio of public welfare safety research initiatives that fill gaps left by government regulatory agencies. These projects include post-accident root cause analysis for electrical fires, safety evaluation for emerging high-risk technologies such as lithium-ion batteries and grid-connected renewable energy systems, and public safety education for consumers.
Global Standard Alignment Impact
UL has developed more than 1600 widely applied safety standards over its history, many of which have been formally integrated into U.S. national ANSI standards and referenced by international IEC and ISO standard frameworks. This cross-border recognition makes UL a core actor in harmonizing disparate regional product safety requirements across the global manufacturing ecosystem.
125 countries
key people
Jennifer Scanlon (President and CEO)
revenue
US$2.68 billion (2023)‡R1R‡
net income
US$276 million (2023)‡R2R‡
num employees
15,000+ (2024)‡R2R‡
parent
Underwriters Laboratories Inc. (non-profit)‡R3R‡
subsid
Futuremark
UL Research Institutes is a global private safety company headquartered in Northbrook, Illinois, composed of three organizations, UL Research Institutes (parent non-profit), UL Standards & Engagement (subsidiary non-profit) and UL Solutions (for-profit business controlled by the non-profits).[4]
Established in 1894, the UL enterprise was founded as the Underwriters' Electrical Bureau (a bureau of the National Board of Fire Underwriters),[5] and was known throughout the 20th century as Underwriters Laboratories.On January 1, 2012, Underwriters Laboratories became the parent company of a for-profit company in the U.S. named UL LLC, a limited liability company, which took over the product testing and certification business. On June 26, 2022, the companies rebranded into three distinct organizations that make up the UL enterprise.
The company is one of several companies approved to perform safety testing by the U.S. federal agency Occupational Safety and Health Administration (OSHA).[6] OSHA maintains a list of approved testing laboratories, which are known as Nationally Recognized Testing Laboratories.[7]
History
Underwriters Laboratories Inc. was founded in 1894 by William Henry Merrill.After graduating from the Massachusetts Institute of Technology (MIT) with a degree in electrical engineering in 1889, Merrill went to work as an electrical inspector for the Boston Board of Fire Underwriters.[8] At the turn of the twentieth century, fire loss was on the rise in the United States, and the increasing use of electricity in homes and businesses posed a serious threat to property and human life.[9]
In order to determine and mitigate risk, Merrill proposed to open a laboratory where he would use scientific principles to test products for fire and electrical safety. The Boston Board of Fire Underwriters turned this idea down, perhaps due to Merrill's youth and relative inexperience at the time.
In May 1893, Merrill moved to Chicago to work for the Chicago Fire Underwriters' Association. His task was to inspect the city's fire alarm systems. He was also sent to the 1893 World's Fair to inspect the Fair's electrical installations and the Palace of Electricity. In order to determine and mitigate risk in his role as an electrical inspector, Merrill found it necessary to conduct tests on building materials and electrical components. Upon seeing a growing potential in this field, Merrill stayed in Chicago to found Underwriters Laboratories. He received initial funding from the Chicago Fire Underwriters' Association and the Western Insurance Union, a local insurance organization. With $350 of equipment, he opened a small laboratory on the third floor of a local fire insurance patrol station, signing UL's first test report on March 24, 1894.
UL Standards
Sustainability Standards
UL 106, Standard for Sustainability for Luminaires (under development)
UL 110, Standard for Sustainability for Mobile Phones
Standards for Electrical and Electronic Products
UL 50, Enclosures for Electrical Equipment
UL 50E, Enclosures for Electrical Equipment, Environmental Considerations
UL 153, Portable Electric Lamps
UL 197, Commercial Electrical Cooking Appliances
UL 244B, Field Installed and/or Field Connected Appliance Controls
UL 410, Slip Resistance of Floor Surface Materials
UL 651, Schedule 40, 80, Type EB and A Rigid PVC Conduit and Fittings
Recognized Component Mark
The Recognized Component Mark is a type of safety certification mark issued by UL Solutions. It is placed on components which are intended to be part of a UL certified end product, but which cannot bear the full UL mark themselves.[48] The general public does not ordinarily come across it, as it is borne on components which make up finished products.
Computer benchmarking
UL offers[49] the following computer benchmarking products:[50]
Merrill soon went to work on developing safety standards, conducting tests, and uncovering hazards. In the early years, UL tested three main types of products: devices meant to stop fire (such as fire extinguishers), devices meant to resist fire (such as fire doors), and devices that frequently caused fire (like wires used for electrical installations).[11] This work soon expanded, and throughout the twentieth century, UL certified many pivotal consumer technologies, such as vacuum cleaners, televisions, microwaves, personal computers, and more.[12]
UL published its first standard, "Tin Clad Fire Doors", in 1903. In 1906, UL established a Label Service for certain product categories that require more frequent inspections. Products that passed UL's testing and regular inspections were given a UL label, which eventually evolved into the UL Mark. From 1905 to 1979, UL Headquarters was located at 207-231 East Ohio Street in Chicago.[13] In 1979, the organization moved its headquarters to a 153-acre campus in Northbrook, Illinois, 25 miles north of its former downtown Chicago location.
UL Solutions has evolved from its roots in electrical and fire safety to address broader safety issues, such as hazardous substances, water quality, food safety, performance testing, safety and compliance education, and environmental sustainability.
On January 1, 2012, Underwriters Laboratories became the parent company of a for-profit company in the U.S named UL LLC, a limited liability corporation. The for-profit company took over the product testing and certification business.
In 2022, the company revised their go-to-market strategy to include three separate organizations - UL Solutions, UL Standards & Engagement, and UL Research Institutes.[14]
UL Solutions became a public company via an initial public offering in April 2024 raising around $950million, valuing the company at about $7billion.The company is listed on the New York Stock Exchange.[2][1]
UL 796, Printed-Wiring Boards
UL 962B, Outline for Merchandise Display and Rack Mounted Power Distribution Units
UL 970, Retail Fixtures and Merchandising Displays
UL 1026, Electric Household Cooking and Food Serving Appliances
UL 1083, Household Electric Skillets and Frying-Type Appliances
UL 1492, Audio/Video Products and Accessories
UL 1598, Luminaires
UL 1642, Lithium Batteries
UL 1653, Electrical Nonmetallic Tubing
UL 1995, Heating and Cooling Equipment
UL 2267 Standard for Safety - Fuel Cell Power Systems for Installation in Industrial Electric Trucks
UL 6500, Audio/Video and Musical Instrument Apparatuses for Household, Commercial and Similar General Uses
UL 60065, Audio, Video and Similar Electronic Apparatuses: Safety Requirements
UL 60335-1, Household and Similar Electrical Appliances, Part 1: General Requirements
UL 60335-2-24, Household and Similar Electrical Appliances, Part 2: Particular Requirements for Motor Compressors
UL 60335-2-3, Household and Similar Electrical Appliances, Part 2: Particular Requirements for Electric Irons
UL 60335-2-34, Household and Similar Electrical Appliances, Part 2: Particular Requirements for Motor Compressors
UL 60335-2-8, Household and Similar Electrical Appliances, Part 2: Particular Requirements for Shavers, Hair Clippers and Similar Appliances
UL 60950, Information Technology Equipment
UL 60950-1, Information Technology Equipment – Safety, Part 1: General Requirements
UL 60950-21, Information Technology Equipment – Safety, Part 21: Remote Power Feeding
UL 60950-22, Information Technology Equipment – Safety, Part 22: Equipment to be Installed Outdoors
UL 60950-23, Information Technology Equipment – Safety, Part 23: Large Data Storage Equipment
UL 61010-1, Safety Requirements for Electrical Equipment For Measurement, Control, and Laboratory Use; Part 1: General Requirements
UL 62368-1, Audio/Video, Information and Communication Technology Equipment – Part 1: Safety Requirements
Life Safety Standards
UL 217, Single- and Multiple- Station Smoke Alarms
UL 268, Smoke Detectors for Fire Protective Signaling Systems
UL 268A, Smoke Detectors for Duct Application
UL 752, Bulletproofing standards
UL 1626, Residential Sprinklers for Fire Protection Service
UL 1971, Signaling Devices for the Hearing Impaired
Standards for Building Products
UL 10A, Tin-Clad Fire Doors
UL 20, General-Use Snap Switches
UL 486E, Equipment Wiring Terminals for Use with Aluminum and/or Copper Conductors
UL 1256, Fire Test of Roof/Deck Constructions
Standards for Industrial Control Equipment
UL 508, Industrial Control Equipment, superseded by UL 60947-4-1[15]
UL 508A, Industrial Control Panels
UL 508C, Power Conversion Equipment, superseded by UL 61800-5-1[16]
UL 61800-5-1, Adjustable Speed Electrical Power Drive Systems
Standards for Plastic Materials
UL 94, Tests for Flammability of Plastic Materials for Parts in Devices and Appliances
UL 746A, Polymeric Materials: Short-Term Property Evaluations
UL 746B, Polymeric Materials: Long-Term Property Evaluations
UL 746C, Polymeric Materials: Use in Electrical Equipment Evaluations.
UL 746D, Polymeric Materials: Fabricated Parts
UL 746E, Polymeric Materials: Industrial Laminates, Filament Wound Tubing, Vulcanized Fiber and Materials Used in Printed-Wiring Boards
UL 746F, Polymeric Materials: Flexible Dielectric Film Materials for Use in Printed-Wiring Boards and Flexible Materials Interconnect Constructions
UL 1635, Standard for Digital Alarm Communicator System Units (ANSI Approved: April 13, 2018)[41]
UL 1981, Central-Station Automation Systems (ANSI Approved: March 29, 2023)[42]
UL 2050, National Industrial Security Systems (Revised: November 7, 2010)[43]
UL 2610, Commercial Premises Security Alarm Units and Systems (ANSI Approved: April 7, 2021)[44]
UL 2900-1, Software Cybersecurity for Network-Connectable Products, Part 1: General Requirements (ANSI Approved: April 14, 2023)[45]
UL 2900-2-3, Software Cybersecurity for Network-Connectable Products, Part 2-3: Particular Requirements for Security and Life Safety Signaling Systems (ANSI Approved: September 21, 2023)[46]
UL Solutions of Canada
CAN/ULC-S101-07, Standard Methods for Fire Endurance Tests of Building Construction and Materials
CAN/ULC-S102-10, Standard Methods of Test for Surface-Burning Characteristics of Building Materials and Assemblies
CAN/ULC-S102.2-10, Standard Methods of Test for Surface-Burning Characteristics of Flooring, Floor Coverings, and Miscellaneous Materials and Assemblies
CAN/ULC-S104-10, Standard Methods for Fire Tests of Door Assemblies
CAN/ULC-S107-10, Standard Methods for Fire Tests of Roof Coverings
CAN/ULC-S303-M91 (R1999), Standard Methods for Local Burglar Alarm Units and Systems[47]
Photovoltaic
UL 1703, Photovoltaic Flat-Plate Modules
UL 1741, Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources
UL 2703, Rack Mounting Systems and Clamping Devices for Flat-Plate Photovoltaic Modules and Panels
8.Engineering Progress: The Revolution and Evolution of Working for a Safer World. UL. Retrieved September 16, 2021.^
9.Knowles, Scott (2011). “Chapter 1: The Devil’s Privilege.” The Disaster Experts: Mastering Risk in Modern America. Philadelphia, Pennsylvania: University of Pennsylvania Press, pp. 21-61.^
10.Harry Chase Brearley. A Symbol of Safety: An Interpretive Study of a Notable Institution Doubleday, 1923^
11.John R. Rathom. Where Fire-Defying Inventions Are Tested The Sunday Record-Herald, November 23, 1902^
13.“Underwriters' Laboratories, 207-231 East Ohio Street, Chicago, Cook County, IL.” Historic American Buildings Survey, Engineering Record, Landscapes Survey, Library of Congress. Retrieved September 16, 2021.^
