In this modern era, the science of safety mainly concerns all possible danger associated with the utilization of existing and/or developing technologies. Through development of the Occupational Safety and Health Act (OSH Act) of 1970, the U.S. Congress created the Occupational Safety and Health Administration (OSHA) to assure safe and healthy working conditions for workers by setting and enforcing standards and providing necessary training, outreach, education, and assistance. Occupational safety and health (OSH) primarily deals with cross-disciplinary areas for the safety, health, and welfare of workers. The goal of OSH programs is to foster a safer and healthier work environment for workers, engineers, students, and other participants. This chapter focuses on the fundamental aspects of safety, accidents and their occurrence and prevention, accident recordings, and social and economic implications of accidents. With the advancement of nanotechnology, the exposure to nanomaterials, as well as to the packaging, transportation, handling, storage, and consumption of these materials, poses higher risks and hazards to people engaged in this and related technologies. This chapter emphasizes the possible dangers of nanomaterials and their harmful effects on human health. The guidelines for working with nanomaterials are also summarized in detail.