The American Herbal Products Association (AHPA), Silver Spring, MD, has submitted a letter to the Food and Drug Administration (FDA) to request that the agency deny a food additive petition that would allow the use of ionizing irradiation on dietary supplements and dietary ingredients. The letter was addressed to Dr. Lane Highbarger at FDA’s Center for Food Safety and Applied Nutrition as the identified contact person for the petition.

The petition that is the subject of AHPA’s letter was submitted by Steris Corp. in 2003, and proposed that the food additive regulations “be amended to provide for the safe use of ionizing radiation for the control of microbial contamination on dietary supplements, and ingredients used in the manufacture of dietary supplements, up to a maximum absorbed dose of 30 kGy” (kiloGray). AHPA became aware of the petition when it was referenced in the preamble to FDA’s final rule on current good manufacturing practice for dietary supplement on June 25, 2007.

In requesting that the petition be denied, AHPA identified several concerns, including that because “proper handling of these ingredients under current good manufacturing practice is usually sufficient to ensure that dietary supplements are not subject to microbial contamination that presents any risk to the health of consumers of these products… there is generally no need for ionizing radiation as a treatment for this class of goods.”

AHPA also noted that irradiation is currently allowed in the U.S. for 11 food categories, and that in proposing that the limitation of ionizing radiation for dietary supplements be established at 30 kGy, the petition “is suggesting that this limit be from 3 to 30 times higher that is currently allowed for all but two food categories.” These two are when used for the sterilization of frozen, packaged meats used solely in the NASA space flight programs, at a minimum dose of 44 kGy, and for microbial disinfection of spices “when used as ingredients in small amounts solely for flavoring or aroma,” at a maximum dose of 30 kGy. AHPA’s letter therefore noted that “Steris Corp. has proposed that only astronauts would be able to obtain foods treated with higher limits of ionizing radiation than dietary supplements, and has apparently ignored the fact that, while spices are used in small amounts, dietary supplements may be consumed in quantities of several grams per day. Thus, dietary supplement consumers will be exposed to much higher levels of any material changes that occur in a supplement’s or ingredient’s characteristics or in its consequences of use, if any, as a result of the irradiation.”

AHPA’s letter also expressed concern that should this petition be approved, “the use of ionizing irradiation on herbal dietary ingredients will mask one of the factors that is currently relevant to the determination of ingredient quality,” since information about microbial levels and the presence of pathogens or yeasts and molds at any time during the handling of a treated ingredient would be lost. The letter stated a “particular concern in the case of pathogens, since even if pathogenic organisms are eliminated through irradiation, pathogenic by-products such as endotoxins or exotoxins may remain in the material.” The letter also went on to express concern that “the United States will become the dumping ground for poor quality herbal ingredients from around the world,” since “irradiation of herbal ingredients is not permitted in many countries.”