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NIST SP 951
Essential Health and Safety Requirements: An ExampleEssential health and safety requirements are at the heart of the New Approach Directives. They are mandatory, legally binding obligations, and they are enforced. Following is one of the essential requirements taken directly from the Machinery Directive. It relates to the starting function:  "Starting. It must be possible to start machinery only by voluntary actuation of a control provided for the purpose. The same requirement applies when restarting the machinery after a stoppage, whatever the cause, when effecting a significant change in the operating conditions (e.g., speed, pressure, etc.), unless such restarting or change in operating conditions is without risk to exposed persons. This essential requirement does not apply to the restarting of the machinery or to the change in operating conditions resulting from the normal sequence of an automatic cycle. Where machinery has several starting controls and the operators can therefore put each other in danger, additional devices (e.g., enabling devices or selectors allowing only one part of the starting mechanism to be actuated at any one time) must be fitted to rule out such risks. It must be possible for automated plant functioning in automatic mode to be restarted easily after a stoppage once the safety conditions have been fulfilled." The aim of most essential requirements is the elimination of risks of accident to the extent possible. All manufacturers, domestic or foreign, are obliged to meet all the essential requirements pertaining to their product. The law does not distinguish between European manufacturers and manufacturers of other countries. Conformity assessment in Europe, therefore, is the process by which compliance with essential requirements is determined. This process can be carried out with or without the use of standards. This last principle is important to manufacturers of new or innovative products for which standards do not yet exist, and ensures that standards annexed to New Approach Directives (which are voluntary) do not become de jure obligatory. Return to the Table of Contents
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