ABSTRACT
This chapter discusses risk assessment and management of chemical substances in relation to environmental laws. The risk of chemical substances depends on how one uses them. For example, nanoparticles may be dangerous, such as asbestos and diesel exhaust. In contrast, supercritical fluids are non-aggregating in the liquid phase and exhibit different properties as solvents. Biochemical oxygen demand (BOD) is not the amount of organic matter in water. It is the amount of oxygen microorganisms need for oxidative degradation. In general, larger values of BOD indicate poor quality of water. Organotin compounds are composed of hydrocarbons and other organic substituents in organic tin compounds. They are used in the commercial manufacturing of polyvinyl chloride, hydrochloric acid scavenger, and thermal stabilizers, or biocides.
