"The process of developing and using occupational exposure limits is a cornerstone of industrial hygiene practice, with a history dating back to the 1880s. Occupational exposure limits, known as OELs, have not—until recently—evolved enough to reflect the advances in related sciences of toxicology, risk assessment, and exposure assessment. Much of the pioneering effort to develop and promote OELs as a risk management strategy occurred in the 1940s..."