The major responsibilities of the NIHS involve extensive testing and research to ensure the quality, efficacy, and safety of chemical substances (including pharmaceuticals and food) that are closely related to people's lives. These activities can be broken down into the following fields:

(1) Pharmaceuticals and medical devices: The NIHS is engaged in testing, evaluation, and related research aimed at maintaining the quality, efficacy, and safety of pharmaceuticals derived from chemical synthesis or organisms, biotechnology-based pharmaceuticals, therapeutics for gene or cell therapy, crude drugs, and medical devices.

(2) Foods: The NIHS engages in research to establish standard methods for analyzing pesticide residues, veterinary drugs, allergic substandes in foods, and food additives. It also conducts testing, research, and surveys to ensure the chemical safety of newly developed foods, food additives, food utensils, packages, and other items, while also conducting studies and testing to prevent health hazards caused by food-poisoning bacteria, microbial toxins, etc.

(3) Other chemical substances to which people are exposed: The NIHS is engaged in testing and research of household products, drinking water, indoor air, etc., from a hygiene-chemistry standpoint. It is also involved in simultaneous pass/fail tests of cosmetics, preparation of codes and standards, and testing and research to evaluate the quality and safety of cosmetics and quasi drugs.

(4) Biological studies: The NIHS conducts testing and research on chemical substances in pharmaceuticals, foods, food additives, substances found in daily living, etc., using experimental animals, tissues, and cells. It is also engaged in research on the establishment of testing and evaluation methods.

(5) Safety information on drugs, foods and chemicals: The NIHS collects information pertaining to the safety of drugs, foods and chemical substances both in Japna and abroad, maintains its own database, and supports testing and research while also cooperating with international organizations. Development and maintenance of network systems to support the research activities of the NIHS is also an important element.

NIHS personnel engaged in the above-mentioned activities include experts in such fields as phamacy, veterinary sciences, medicine, agricultural sciences, chemistry, physical sciences, engineering, biology, and nutrition.