Listing: A product safety certification project in the United States is referred to as a "Listing" evaluation, with a compliant product referred to as a "Listed" product. This process involves review and test of the product to all the requirements in the applicable UL standard(s) = construction requirements, markings, instructions, as well as compliance testing. Once the product is "Listed", the manufacturer may apply the "Listing" mark to all units produced in the same manner. Periodic, unannounced inspections by the certification agency are performed at the manufacturing facility to insure that products bearing the "Listing Mark" continue to comply with the requirements. The Listing program is covered by Federal Law and is managed by DOL/OSHA. Agencies accredited by OSHA are referred to as a "NRTL" - Nationally Recognized Test Lab. Each US NRTL is accredited for specific UL standards. All jurisdictions in the country must accept the NRTL Listing mark under Federal Law.
Field Labeling: A field labeling review in the United States is frequently referred to as a Field Evaluation (FE), with a compliant product bearing the "Field Labeling Mark" of the certification agency. The field labeling program is not part of the Federal NRTL Listing program - it is independent and presumes the local inspector will accept the Field Labeling Mark in lieu of a Listing Mark. Only the actual products inspected may bear the Field Labeling Mark, and the Mark must be applied by the Certification Agency engineer. No other products are covered - the manufacturer is not permitted to claim that any other units and/or future production are certified. Additional units need to be individually inspected and labeled. (A similar program exists for Canada using CSA standards.)
The Field Labeling program is primarily intended for single design products, custom products, and other industrial and commercial systems that are not practical to "List". Home appliances are not precluded from the Field Labeling program, although it is rare since most home appliances need Listing for continued production. Some companies have initial units Field Labeled while working toward a Listing. Some companies repeatedly Field Label their products and never get a Listing. Most Field Labeling must be done at the installation site. Some cord connected products may be Field Labeled at the Certification Lab before delivery to the customer.
A Field Evaluation uses the same UL standard(s) as a Listing evaluation. However, the certification agency is allowed to use some leeway and engineering consideration based on the single unit, specific user, and other factors that may apply only to the unit being inspected. This can mean some loosening of the requirements. Field Evaluations also involve limited testing since the unit being inspected is to be used after the review - this includes no destructive testing. Component Certification is an important consideration for both Field Labeling and Listings.
CertifiGroup operates one of the largest Field Labeling Groups in the US in partnership with MET Laboratories Inc., a US-NRTL. CertifiGroup also operates a full US-NRTL Listing, Canadian-C, European-CE, and International-IEC Certification Laboratory.