Impurities and Contaminants in Food Supplements

On the basis of recommendations of the USP Botanical Dietary Supplements and Herbal Medicines Expert Committee and the Non-Botanical Dietary Supplements Expert Committee, a new USP general chapter <2760> Impurities and Contaminants in Dietary Ingredients and Dietary Supplements is being proposed. The chapter has been published in Pharmacopeial Forum (PF) 51(5) and is open for comments until 30 November 2025.

Background and Scope

Specifications for impurities and contaminants are critical quality attributes because they have the potential to affect the safety and stability of food supplements. Previously, the USP Chapter <1086> Impurities in Drug Substances and Drug Products also applied to food supplements and ingredients. However, this changed in May 2021, when chapter <1086> was revised to concentrate on drug substances and drug products and to be consistent with the corresponding ICH Q3 guidelines.

The proposed new chapter <2760> reviews the types, sources, exposure, control, and toxicity of impurities and contaminants. The chapter also contains analytical methods and discusses existing challenges to measure impurities and contaminants in food supplements including some risk assessment considerations. 

Commonly occurring contaminants that have been detected and quantified in food supplements, include the following:

• Heavy Metals
• Toxins (e.g. Aflatoxin, Ochratoxin) 
• Pyrrolizidine Alkaloids (PAs)
• Pesticides
• Dioxins, Furans, and Polychlorinated Biphenyls (PCBs)
• Polycyclic Aromatic Hydrocarbons (PAHs)
• Per- and Polyfluoroalkyl Substances (PFAS)

However, microbial contamination is not covered in this chapter. Testing requirements and specifications for microbial contaminants can be found in USP chapter <2023> Microbiological Attributes of Nonsterile Nutritional and Dietary Supplements. In addition, foreign organic matter and allergens are not covered. The consideration of allergen cross-contamination and cross-contact is a significant obligation for food manufacturers under CGMP. Thus, manufacturers are obligated to develop allergen control plans that address storage, cleaning, environmental monitoring, training, and periodic finished product testing to ensure that their allergen controls are operating in a state of control. Further food supplement product tests are provided in the new USP chapter <2800> Multi-Ingredient Dietary Supplement Products - Product Quality Tests.

More information is available following registration to the Pharmacopeial Forum.