The general public is exposed to a wide variety of chemicals through the air, water, soil, food, consumer products, or during occupational activities. Human biomonitoring (BM) measures the concentration of these substances in the body using various biological samples (blood, urine, hair, exhaled air, etc.). It provides useful information on exposure from the general environment or the workplace. This practice, which has established itself over the past twenty years in France as one of the methods contributing to the understanding and prevention of chemical risks, presents similarities and differences in approach between the general population and workers; it also has limitations. Thus, regardless of the population concerned, BS allows for the integration of all routes of absorption and sources of exposure. Other similarities can be highlighted, such as the selection of biomarkers based on metabolism and toxicokinetics, rigorous procedures for collection, sampling, storage, and transport, and the appropriate selection of the analytical laboratory. Nevertheless, several differences exist between environmental and occupational BS. These relate to the regulatory framework, the stakeholders involved in the activity, the timing of sampling, the reference standards used for interpreting results, and the manner in which these results are reported. Limitations specific to BM can be noted, regardless of the population of interest: lack of biomarkers for all chemical substances, difficulty in linking a test result to a health effect, etc. Ultimately, these two approaches to biomonitoring contribute to a better understanding of chemical risks to the population.