A major issue in modern workplace safety is the protecttion of workers from the chemicals, chemical intermediaries, by-products, and waste products involved in chemical and material processing and manufacture. These chemicals can have both immediate effects and long-term health effects. Miller Engineering has worked on several projects involving worker health issues related to exposure to harmful chemicals. Our experience with OSHA Personal Protective Equipment (PPE) standards, as well as safety labeling and MSDS, give us a unique perspective on this issue. Often, these projects require the ability to trace the historical knowledge of both medical and industrial hygiene professionals back to the early- or mid-1900s, as many exposures that began in that time period are just beginning to result in health problems today.