To ensure the safety of workers the exposure to chemical substances should be as low as reasonably possible. There are several ways to measure the exposure. Two promising techniques that could complement current measuring techniques are biomonitoring, to assess internal exposure, and sensoring, to assess external exposure. Information acquired through these methods can be used for worker health protection. Careful application of these techniques is important. This also includes considerations on dealing with private information under privacy law and whether workers should be able to decide for themselves to join measurement campaigns. The balance between pros and cons should be beneficial for the worker. To create a positive balance, it is crucial that the measurement data are indeed used to protect the worker. This is based on the RIVM research that lists the pros and cons of these techniques with respect to both practical and ethical aspects. The information gathered serves as background information to support discussions within the Social and Economic Council of the Netherlands (SER) about the question whether or not to apply these techniques more prominently in the Netherlands. The report describes how effective biomonitoring and sensoring are (and to what aim), and the extent to which exposure measurements can be intrusive, for instance concerning bodily integrity. In addition, the report addresses the rights, duties and responsibilities of key-actors, such as employers, employees, and health and safety workers (physicians and occupational hygienists). They have a shared responsibility to determine if the exposure measurements and exposure reduction measures are proportional to the goals at hand. Biomonitoring is used to determine substances in bodily fluids, such as blood or urine, as a measure for exposure. On a small scale it is used in the Netherlands and more often across Europe and in the United States of America. Biomonitoring is very useful for those substances that are difficult to measure in the air or if dermal exposure is the main route of exposure. A disadvantage is that bodily fluids are required. Furthermore, the number of substances for which measurement protocols and biological limit values exist is limited. Sensoring is used to measure substances using small electronic devices (sensors). The advantages are that the devices provide real-time results and are easy and light weight to wear. A disadvantage is that the measurements are difficult to relate to specific activities of the worker. Also, they are not yet suitable to test exposure to limit values.