Metal Impurities in Food and Drugs
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The major metals of potential health concern found in food, drugs (medicines), and dietary supplements are lead, cadmium, mercury, and arsenic. Other metals, such as chromium, copper, manganese, molybdenum, vanadium, nickel, osmium, rhodium, ruthenium, iridium, palladium, and platinum, may be used or introduced during manufacturing and may be controlled in the final article as impurities. Screening for metals in medicines and dietary supplements rarely indicates the presence of toxic metal impurities at levels of concern. The setting of heavy metal limits is appropriate for medicines and is appropriate for supplements when heavy metals are likely or certain to contaminate a given product. Setting reasonable health-based limits for some of these metals is challenging because of their ubiquity in the environment, limitations of current analytical procedures, and other factors. Taken together, compendial tests for metals in food and drugs present an array of issues that challenge compendial scientists.
KEY WORDSanalysis impurities limits metals standards US Pharmacopeia
Agency for Toxic Substances and Disease Registry
Centers for Disease Control and Prevention
Current Good Manufacturing Practices
Environmental Protection Agency
Food and Drug Administration
Graphite Furnace Atomic Absorption Spectroscopy
International Agency for Research on Cancer
Inductively Coupled Plasma–Optical Emission Spectroscopy
Inductively Coupled Plasma–Mass Spectroscopy
International Program on Chemical Safety
Integrated Risk Information System
Joint Expert Committee on Food Additives
Lowest Observed Adverse Effect Level
Minimal Risk Level
No Observed Adverse Effect Level
Office of Environmental Health Hazard Assessment
Permissible Daily Exposure
US Pharmacopeial Convention
World Health Organization
The authors thank Stefan Schuber, Ph.D., ELS, director of scientific reports at USP, for editorial assistance.
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