The term mechanical integrity became popular as a result of its use by the U.S. Occupational Safety and Health Administration (OSHA) in the 1992 standard on Process Safety Management of Highly Hazardous Chemicals. [1] The law, OSHA 1910.119, provides requirements for preventing or minimizing the consequences of catastrophic releases of toxic, reactive, flammable, or other listed "highly hazardous" chemicals. The regulation requires inspection and testing of equipment using written procedures and trained employees.

Marcel Decker, Inc., New York, granted their kind permission to use major selections from Chapter 12 of the Handbook of High Toxic Materials Handling and Management (1995), entitled "Mechanical Integrity" by Roy E. Sanders. [2]

The federal standard regulates facilities that handle nearly 140 specifically listed, highly-hazardous chemicals (above a threshold quantity which is different for different substances) and certain processes involving flammable liquids or gases in excess of 10,000 pounds (4,540 Kg). While the law may not cover some highly toxic materials and flammables in quantities less than their threshold or 10,000 pounds for flammables, it does present a good benchmark for examining programs to ensure containment. The techniques discussed in this chapter are not new, yet they are not universally used at this time.

The Occupational Safety and Health Administration, OSHA, Compliance Directive [3] identifies the intent of a "Mechanical Integrity" program:

is to assure that equipment used to process, store or handle highly hazardous chemical is designed, constructed, installed and maintained to minimize the risk of...