Survey of bioeffects data and format of standard exposure boundaries

As increasingly more applications of lasers are formulated, the gaps in our quantitative data base of biological data are highlighted. In the past, just as now, research is tied to the need for safety data for specific applications. All too often in the past ambiguity or large disjunctions in the expression of the safety limits were ignored because “nobody uses a laser here anyway.” Such a cavalier attitude is rarely possible anymore as lasers are at all wavelengths and pulse durations, even as in the ultrashort pulse range where only guidelines have been offered to data due to lack of quantitative experimental information. As the gaps in our information are filled, another problem arises. The original formulation of the safety limits was intended more as a backup for the classification scheme, and there were only a few lasers to classify. As only a relatively few experts used the safety boundary equations either to classify new lasers or to deal with applications not easily covered by standard classification schemes, the mathematical formulations of the boundary conditions were not clearly stated and required cumbersome calculations and references to several tables before any correct answer could be determined. The next revision of the American Conference of Governmental Industrial Hygienists and ANSI documents will embody some changes intended to simplify the calculations and make them more rational. Some examples are the use of dimensionally correct equations and decimal exponents.