Possession of a Doctor of Philosophy (PhD) degree in toxicology; or, a PhD in a physical, biological, or environmental science with 10 semester (15 term) credits in a one or more subject areas including toxicology, human or environmental risk assessment, pharmacology, pathology, environmental stress, mechanisms or modes of chemical action on living organisms; and an additional 10 semester credits (15 term) in any combination of the following: molecular biology, biochemistry, chemistry, anatomy, epidemiology, industrial hygiene, zoology, ecology, biology, limnology, environmental science, soil science, physiology, histology, statistics, and chemical fate and transport. Possession of a master's degree in a physical, biological, or environmental science with 10 semester (15 term) credits in one or more of the following subject areas: toxicology, human or environmental risk assessment, pharmacology, pathology, environmental stress, mechanisms or modes of chemical action on living organisms; and an additional 10 semester credits (15 term) in any combination of the following: molecular biology, biochemistry, chemistry, anatomy, epidemiology, industrial hygiene, zoology, ecology, biology, limnology, environmental science, soil science, physiology, histology, statistics, and chemical fate and transport.