A procedure for multiple-pulse maximum permissible exposure determination under the Z136.1-2000 American National Standard for Safe Use of Lasers

The current national consensus standard for laser safety in the United States is the American National Standard for Safe Use of Lasers (ANSI Z136.1). Over the past few years, a comprehensive rewrite of this standard has been conducted. The updated version of the standard (Z136.1-2000) incorporates a wealth of new bioeffects data and establishes a number of new maximum permissible exposure (MPE) limits for laser safety. The updated standard also includes new procedures for the computation of MPE values, which must be understood by health physicists, laser safety officers, and others in the field of occupational safety. Here we present the first in a series of tutorial articles to clarify laser safety analysis procedures under this new standard. This article deals with the proper application of three rules for determining the appropriate MPE values for repetitively pulsed lasers or repeated exposures from laser beams.