The Occupational Safety and Health Administration (OSHA) in the United States is responsible for the promulgation and enforcement of rules to protect and enhance worker safety in most medium and large commercial enterprises. To that end, the agency has collected and processed more than 240,000 atmospheric samples of chemicals and aerosols in a variety of workplaces in the past 30 years. Though the agency spends more than 500 million per year even in the face of increasing overall employment, there exist only targeted evaluations of OSHA sampling activity for specific issues like formaldehyde or silica in the published literature. This paper presents a comprehensive analysis of this effort including assessment of the hazard potential distribution of sampled workplace atmospheres for all recorded pollutants over the time period from 1984 to 2011, the budgetary requirements of this activity over time in comparison to the assessed risk, and an evaluation of the probable effectiveness of such activity given changes in US industrial employment over that time period. The effectiveness of the sampling program is assessed according to specific criteria including the probability of detecting exceedances of the National Institute of Occupational Safety and Health (NIOSH) recommended exposure limit (REL) for individual pollutants, the trend in the overall hazard level of detected atmospheres, the coverage of industries by worker population, and the cost-efficiency of the program in identifying hazardous atmospheres. Special attention is given to lead, toluene, and various mineral-and metal-based particulate matter, which have all seen new rules implemented in the recent past. Findings show that the number of samples per employed person has decreased markedly since the beginning of the study period and become less aligned with the changes in population distribution among US regions, however the probability of detecting a hazardous level of a chemical or aerosol pollutant has increased. Extrapolations of this information and the associated changes in industrial sector employment indicate that US workplace atmospheres are marginally less hazardous at the end of the study period than they were at the beginning.