Private Agencies
Underwriters Laboratories (U.L.) and TUV are examples of private agencies that have established regulatory standards. However, without extended affiliations with government and other organizations, these agencies would be of little significance.

U.L., for example, works with insurance underwriters. When a product is certified as "safe" by U.L., an insurer has a reasonable expectation that common failures that occur when products are being used appropriately, will not result in excessive damages and/or claims against the insurer.

Combination of Private and Government Regulations
To continue with the example of U.L., in the United States, certain agencies are evaluated and certified by OSHA (Occupational Safety and Health Agency) as "Nationally Recognized Test Laboratory" (NRTL). Several labs besides U.L. have achieved this certification. If an employer is selecting equipment for use in the U.S. workplace, they typically select equipment that meets OSHA requirements, i.e., equipment that has passed safety testing at a NRTL.

Safety Regulations
Objectives for these regulations include reducing the risk of:

• Electric shock or electrocution
• Fire (and consequent spreading of fire)
• Toxic emissions of chemicals or vapors
• Physical injury (cuts, falls, burns, dropping equipment)
• Exposure to radiation

To see an example of a process flow chart for parts selection, where U.L. system approval is the ultimate goal, click here.

Electromagnetic Compatibility (EMC) Regulations
These regulations address 2 general concepts:

• Emissions- the amount of interference coming from equipment
• Immunity- a measure of how well the equipment functions when subjected to "typical" interference

Testing
Products are tested according to the specific standard. Most standards have details on the methods and equipment required to ensure the tests will be conducted properly.

How Compliance is Determined
The most common methods involve steps such as these:

• The manufacturer builds a sample and submits it to an authorized test lab. Along with the sample, specifications and certifications for key safety components may be provided by the manufacturer.
• The lab/agency evaluates the design by testing the sample and evaluating other documents.
• The lab/agency determines that the unit complies with the standard.
• The agency conducts followup inspections of the manufacturer to ensure that the products continue to built to the same specifications as the sample that was submitted. An alternative to inspection may be "self-monitoring" by the manufacturer, as prescribed by the manufacturer's "quality system."

Agency Markings and Certifications
Two categories apply here:

• Self-declared: The manufacturer certifies that the applicable standard(s) have been met. The European "CE Marking" is an example.
• Agency or government authorized: The agency (or government) owns the copyrighted mark, and controls the use/placement of said mark. Examples here include the CSA (Canadian Safety Agency), U.L., and TUV Rheinland marks. These organizations require the manufacturer to submit to factory inspections as mentioned previously.