The use of engineered nanomaterials (ENM) grows at an increasing pace, and consumer and industrial applications cover new product groups and industry sectors. Currently, the word ‘engineered nanomaterial’ is used less and less, and emphasis is on the practical and concrete applications of specially featured nanomaterials, one example being the use of quantum dots in television screens and medical imaging. The development has meant spreading of nano-sized materials widely in the society, especially in the workplaces. Even though exact numbers of exposed workers are still missing, one may envisage that workers in excess of one million individuals are currently exposed to various classes of engineered nanomaterials in their every day working life, and this number will grow in the future. Considering the prevention of potential hazards of ENM in the occupational environment, a generic approach is the promotion of understanding the ways ENM may cause hazards, and then using this understanding in identifying the potentially harmful ones. This process is effectively promoted by novel findings of ENM-related basic and applied research on their safety. However, much can be done at workplaces to prevent exposure of workers to ENM by using common sense and what is already known about behavior of particles and ventilation, the most important exposure route of ENM being inhalational. In workplaces, it is crucial to know and list which materials exist in the occupational environment and where, where they are being stored, and whether they are used according to regulations. Existing ventilation solutions can also be effective in reducing exposure to ENM, especially various local exhaust solutions. One can also use wet processes whenever possible, and closed spaces for isolated processes when this can be safely organized. Currently there are a number of approaches to prevent ENM-induced potential hazards, from emerging hazard preventions methods to practical work organization at workplaces. Supported by EU 7^th FP funded NANOSOLUTIONS Project.