Software FAQ

• What requirements does Underwriters Laboratories Inc. (UL) use to assess my product?

  ANSI UL 1998, the Standard for Software in Programmable Components IEC 61508 Functional Safety of Electrical/Electronic/Programmable Electronic Safety Related Systems, or other relevant safety standards for the Programmable Systems Certificate. ANSI UL 1998 was developed using input from industry and regulatory agencies. As an ANSI-accredited Standards Development Organization, UL follows an open standards development process to promote public scrutiny and achieve broad-based consensus standards. UL adheres to strict due process procedures to satisfy concerns for all sectors of the population affected by the adoption and application of a UL Standard.

  UL can perform safety investigations to several international standards:

  • IEC 60601-1-4 Programmable Electrical Medical Systems
  • IEC 61508 Functional Safety: Safety-Related System (consists of seven parts)
  • EN 1050 Safety of Machinery Risk Assessment
  • ISO 14971 Medical Devices - Application of Risk Management to Medical Devices
  • ISA S84.01 Application of Safety-Instrumented Systems for the Process Industries (in use since April 1996)
  • IEC 60730 Automatic Electric Controls for household and similar use
  • IEC 61511 Functional Safety - Safety Instrumented Systems for the Process Industry sector and
  • others as advised

• How does UL's software safety review differ from an ISO 9001 audit of software development?

  ISO 9001 specifies that a manufacturer complies with its documented Quality Management System. UL 1998 addresses the detailed safety-related characteristics of specific software in a product. A portion of the software safety review involves an on-site audit, which can be effectively integrated with an ISO 9001 initial or surveillance audit. UL can prepare a proposal for interested parties.

• When is the best time to get software reviewed?

  UL 1998 reviews can begin early in the software design process and continue throughout development. Identifying safety risks early allows manufacturers to avoid extensive software redesign later, which helps trim software development time and costs.

• How long does it take to have software certified?

  That depends on the size, complexity and functionality of the product. It also depends on the available documentation. UL divides the investigation service into two streams. One is a review of the software development life cycle with respect to the verification and validation activities related to hazard analysis and mitigation. The second is an assessment of design with respect to failure mode and stress testing of the software and related electronics.

• What will it cost to have software reviewed for conformity assessment?

  It depends on the complexity and functionality of the software. UL will provide you with a quote. Contact us in the United States or Canada at +1-888-ULSOFT1 (+1-888-857-6381), or via e-mail at software@ul.com, or fill out the contact us form.

• What happens if software changes are made after certification?

  UL 1998 and the Programmable Systems Certificate include provisions for software updates and changes so that manufacturers don't have to start over with each modification.

• How does this software certification fit in with UL's traditional services?

  The Programmable Systems Certification service is an adjunct service, which means it complements UL's traditional electro-mechanical product investigation. UL can investigate software before, during or after a traditional UL product investigation. Upon satisfactory completion of a software investigation, the PSCS engineer will issue a certificate stating the software meets all conformity assessment criteria outlined in the standard used for the investigation.

  In some product categories, proposals have been made to include UL 1998 requirements in the applicable safety standards. For instance, UL 353, Standard for Limit Controls specifies an effective date of April 30, 2004, for compliance to UL 1998, Standard for Software in Programmable Components, for products that rely on software to perform safety-related functions. UL is reviewing all of its electrical Standards in light of software requirements.

  The following are some of the UL Standards and outlines, applicable to end-products, that specifically reference UL 1998:

  • UL 325 -- Garage Door Opener
  • UL 353 -- Limit Controls
  • UL 372 -- Primary Safety Controls for Gas- and Oil-Fired Appliances
  • UL 1699 -- Arc Fault Circuit Interrupters
  • UL 1740 -- Robots and Robotic Equipment
  • UL 1741 -- Inventers, Converters and Controllers for Use in Independent Power Systems
  • UL 2202 -- Electric Vehicle (EV) Charging System Equipment
  • UL 2231 -- Electric Vehicle (EV) Supply Circuits
  • UL 60730-1 -- Automatic Electric Controls for Household and Similar Use
  • UL 61496 -- Electro Sensitive Protective Equipment
  • Others

• Does UL provide follow-up services for the software certification part of my product listing?

  Yes. In addition to UL's traditional Follow-Up, which includes the programmable systems configuration, at the end of a successful investigation of the software, a maintenance review agreement is informally established to identify which modules, if changed, could affect safety. It also specifies the conduct of risk analysis and activities needed for all enhancements, adjustments and changes both planned and unplanned. The maintenance review agreement establishes a maintenance review schedule that is coordinated with the product development plan.

•