Documentation is an essential part of a safety evaluation. The following describes some of the requirements for components and supporting documentation needed when evaluating a product to safety standards.

Model Names: A manufacturer's product model name (or number) distinguishes that product from other products produced by that manufacture. Safety organizations rely on the manufacturer's model names for tracking and control of materials, components, assemblies and end products. When verifying that model names agree, all characters must be the same. The failure to correctly identify a model name can be an expensive error that can make certification, reports or support documentation invalid.

NRTL Certification: Certification by a Nationally Recognized Testing Lab (NRTL), such as UL, will require support documentation for showing Safety Critical Components and OEM products have the appropriate NRTL approvals. Normally evaluations by UL will require most Safety Critical Components or OEM products have UL approval of some form. CE Marking applies only to products going to the European Union and has no meaning to NRTLs.

Notified Body Certification: Certification of a product by a European Notified Body such as TÜV, VDE, etc., normally requires safety critical components comply with the appropriate EN or IEC standard and these components must be certified by a Notified Body. Verification of compliance is achieved by obtaining a copy of the component's Notified Body license. Notified Bodies do not accept CE marking as a means to show a component complies with European safety standards.

CB Reports: When obtaining a CB Report and Certificate from a CB Scheme Testing Laboratory for an end product, some assemblies used in the end product (such as power supplies) could require their own CB Report and Certificate to support the end product CB Report.

Safety Critical Components: These are components with functional characteristics that affect the safe use of the product. Certification by a NRTL or NB should be verified by obtaining a copy of the license or certificate. Manufacturer's data sheets will be needed for review to verify the component is being used within the manufacturer's specifications.

CE Marking: CE Marking of a product requires most Safety Critical Components comply with appropriate EN or IEC standards. The use of components with CE Marking is an acceptable approach for many components, provided a valid Declaration of Conformity identifies the component by model name, the appropriate EU directive(s) and standard(s), and other required information. Component support information should be included in the end product Technical Data File. The use of safety critical components that have been certified by a European Notified Body such as VDE, TÜV, etc. is also an acceptable approach. For some components or materials certification by UL is satisfactory.

The following is a list of components which typically are Safety Critical Components: