environment. The automobile emission standards of the state of California, for example, are stricter than those applied at the national level.
Standards would be unable to fulfill any of the many purposes just outlined without some degree of confidence that manufacturers' claims for their products of conformity to standards are correct and justified. Such assurance can come from the firm's internal procedures for meeting standards; from review by an independent, private source outside the firm; from a government-mandated regulatory program; or from a combination of such elements.
Conformity assessment is the comprehensive term for procedures by which products and processes are evaluated and determined to conform to particular standards. As distinct from standards development, conformity assessment may be thought of as a central aspect of the use of standards. In the context of many commercial and regulatory uses of standards, measures to evaluate and ensure conformity are of as much or more significance than the standards themselves. They impose significant costs in manufacturing through testing, inspection, audit, and related procedures. The benefits that mitigate these costs accrue from the value added by increased buyer (or regulator) confidence that a product or service meets a standard.22
As noted previously, standards facilitate commerce by informing prospective buyers about aspects of products and services. An implicit element in this communication is the need for trust on the buyer's part that a product meets cited standards. Often, the reputation of the producer expressed in his or her brand name is adequate to establish this confidence. However, when a consumer looks for a recognized certificate of approval on a product, he or she gains additional assurance that the product has been independently tested and verified against applicable standards.23 A well-known certification mark found on many products is the ''UL" label. This mark is owned and managed by Underwriters Laboratories, a nonprofit institution that develops safety standards and tests and certifies many consumer and other products.24
The efficacy of regulation similarly depends on the reliability of measures to determine that products and processes comply with mandatory standards. Regulatory enforcement often—though not always—depends on assessment of the producer's compliance with regulations by an independent inspector or testing laboratory. Building inspection and water quality testing are examples of state and local government assessment of compliance with standards. Many independent, private-sector laboratories also test products for regulatory compliance.
Testing, manufacturer's declaration of conformity, independent certification, laboratory accreditation, and quality system registration are the key elements of the U.S. and international conformity assessment systems. Each of these elements figures prominently in the overall impact of standards on U.S.