Underwriters Laboratories

In the general service agreement that the manufacturer signed with Underwriters Laboratories Inc. (UL)  when product certification was first established, it is stated that it is the manufacturer's responsibility to ensure that products made to bear UL Marks (Listing, Classification or Component Recognition) continuously comply with the applicable UL requirements (the Follow-Up Service Procedure and/or UL Standard). After the establishment of product certification, UL field representatives make periodic inspection visits to factories where certified products are manufactured to determine ongoing compliance with UL requirements. These visits are one method of verifying that the processes and systems in place at a manufacturing facility are effective in meeting requirements.

When a product does not comply with the Follow-Up Service Procedure, applicable standard or other UL requirements, UL field representatives document the nonconformance on a variation notice (VN). A variation notice is a channel of communication between UL and a manufacturer and creates a record when nonconformances are discovered. The issue may be a nonconformance with any UL requirement, but VNs are often written because the construction of product does not comply with requirements in the Follow-Up Services Procedure.

When a nonconformance is found in the field or during a Follow-Up Service visit at the factory, it is important for a customer to address not only the product nonconformance, but also any underlying process or system issue that may have led to the nonconformance. Appropriate containment and system-level corrective action are necessary to assure that all products bearing the UL Mark comply with UL requirements, and that action is taken to reduce the likelihood of the same nonconformance from recurring.

When a VN is issued, a manufacturer has three options for handling nonconforming UL Marked products:

1. Modify all nonconforming UL Marked products to bring them into compliance with the Follow-Up Service Procedure.
2. Remove any markings on the product referring to UL, or obliterate these markings if the marking is imprinted, die-stamped, molded, etc.
3. Make a request to UL for a revision to the UL Follow-Up Service Procedure to include the new or revised construction. While this is occurring, a manufacturer shall hold shipment of all UL Marked nonconforming products pending revision of the Follow-Up Service Procedure or further instructions from UL. Shipment of nonconforming product with the UL Mark must be suspended until UL has reviewed the new/revised construction and determined whether it is acceptable. UL may grant temporary acceptance to a manufacturer for a limited period of time while the Follow-Up Service Procedure revision is under consideration.

In addition to any option above, a manufacturer is also required to investigate the root cause of the VN and to take action to prevent a nonconformance from recurring. Examples of such actions include providing additional training, revising work instructions, providing job aids, revising engineering change and procurement processes, etc. While a formal written corrective action plan is not currently required, a UL field representative will review with a manufacturer the acceptability of any action plan in preventing the nonconformance from recurring before closing the VN.

A manufacturer is responsible for forwarding a copy of the VN to the applicant. In addition, variation notices are available to both manufacturers and applicants at UL's customer portal, MyHome @UL.

CAS involvement is necessary when option 1 is chosen by the manufacturer to request a review by UL for a revision to the FUS Procedure. To resolve these items, a letter of comment from the applicant is typically required to assist the UL engineer in evaluating and determining the acceptance of the request. UL expects to receive the applicant's letter of comment (via e-mail, facsimile, or mail) within 15 days from the date of the variation notice. The sooner UL receives this letter of comment, the earlier the UL engineer can start evaluating the items on the variation notice. If units are on hold, it becomes crucial for the applicant to expedite the letter. In some cases, the letter of comment is not required if the applicant signs the variation notice giving UL authorization to make the changes and the items as documented require no additional information.

The applicant's letter of comment should be sent to the conformity assessment services department at the UL office where the applicant's file is normally handled. Depending on the type or nature of the item, the UL engineer may decide that additional testing is necessary. When that occurs, the work process is similar to a new work investigation.

When the UL engineer completes the evaluation of all the items on the Variation Notice, he provides resolution for each item in a conclusion letter to the applicant. In this letter, he clearly indicates if the item is acceptable or unacceptable, and if acceptable, whether or not the resolution of the item results in the Follow-Up Service Procedure revisions. A copy of this letter is also sent to the manufacturer and the UL field representative. If the resolution of the item results in the Follow-Up Service Procedure revisions, the manufacturer will receive the revised pages shortly.

If there are items concluded as unacceptable, the manufacturer must choose options 1 (modify all nonconforming UL Marked products to bring them into compliance with the Follow-Up Service Procedure) or 2 (remove any markings on the product referring to UL, or obliterate these markings if the marking is imprinted, die-stamped, molded, etc.) to resolve the nonconformance.

A final unacceptable decision rescinds any temporary acceptance granted by the UL field representative at the time of inspection. To confirm compliance, the UL field representative will visit the manufacturer for a re-inspection of the nonconforming product. UL may request the manufacturer to issue a recall of products that were shipped, which did not comply with all UL requirements.

It is in the manufacturer's best interest to prevent the occurrence of variation notices. First, this is a violation of the agreement with UL that allows the manufacturer to place UL Marks on the products. Second, they can cause production interruptions to the manufacturer.

Variation notices and other information relative to a manufacturer's nonconformance history, if significant, can lead to a UL decision to place the manufacturer on an increased inspection program. This will cause the manufacturer additional cost for inspections that are conducted beyond the normal frequency and can result in withdrawal of the authorization to use the UL Mark.

One of the common reasons a manufacturer receives variation notices is incorporating product construction changes not covered in the Follow-Up Service Procedure. To prevent this, the applicant should submit any product construction changes to UL for evaluation and acceptance before they are incorporated into products that are intended to bear UL Marks. Another common reason is component substitution not covered in the Follow-Up Service Procedure. To prevent that, the manufacturer should request that the applicant obtain UL authorization before proceeding with the component substitutions.

To understand traceability requirements, the applicant should discuss this with UL's Conformity Assessment Services Department during the product investigation and inquire about the possible need for the split inspection or the use of UL's traceability programs so that purchased parts are assured of complying with UL's requirements. UL's traceability programs are available for the following categories: Recognized Component, Fabricated Parts, Processed Wire, Wiring Harness, Printed Wiring Board Assemblies, Information Technology and Telephone Equipment Subassemblies, Repackaged Product, and Unlisted Component.

You can discuss any questions with your local field services representative, your customer service professional or your normal conformity assessment services contact.