OR Substitution of Experience: Two years of graduate education or a Masters degree in safety or occupational health fields (safety, occupational health, industrial hygiene) or degree in other related fields that included or was supplemented by at least 24 semester hours of study from among the following or closely related disciplines: safety, occupational health, industrial hygiene, occupational medicine, toxicology, public health, mathematics, physics, chemistry, biological sciences, engineering, and industrial psychology. Undergraduate and Graduate Education: Major study in safety or occupational health fields (safety, occupational health, industrial hygiene) or degree in other related fields that included or was supplemented by at least 24 semester hours of study from among the following or closely related disciplines: safety, occupational health, industrial hygiene, occupational medicine, toxicology, public health, mathematics, physics, chemistry, biological sciences, engineering, and industrial psychology.