products in trade, homeopathic herbal preparations, essential oils, herbal products to which chemically-defined active substances had been added, or environmental factors, additives or contaminants” (McGuffin et al., 1997).
The AHPA review committee followed guidance from the World Health Organization’s (WHO) Programme on Traditional Medicines (WHO, 1991), which states that regulatory action is not necessary for traditionally used products that have not been shown to be harmful unless new evidence necessitates a risk–benefit assessment. According to AHPA, the safety classification was based on an assumption of rational, informed use of botanicals and the committee reported that it carefully considered the intended use of the substance within the historical context of that use (McGuffin et al., 1997). As listed in the exclusionary criteria above, the committee also reported that it did not extrapolate toxicity data of isolated constituents and did not use data from studies that had excessive or irresponsible consumption patterns (McGuffin et al., 1997).
Once the committee reviewed all available information, the botanicals were assigned to one of four safety classes. Class 1 substances are botanicals that the AHPA committee believes can be used safely when used appropriately. Class 2 substances are botanicals for which certain restrictions apply (see subclasses) unless otherwise directed by an expert qualified in the use of the substance. Class 2a substances are botanicals only to be used externally. Class 2b substances are botanicals not to be used during pregnancy. Class 2c substances are botanicals not to be used while lactating. Class 2d substances are botanicals for which other use restrictions have been specified in the monograph. Class 3 substances are botanicals for which significant data exist to recommend special labeling: “To be used only under the supervision of an expert qualified in the appropriate use of this substance.” Finally, class 4 substances are botanicals for which the AHPA committee found insufficient data for classification (McGuffin et al., 1997).
In 1997 the Food and Nutrition Board, IOM, National Academies, published its first report on Dietary Reference Intakes (DRIs) (IOM, 1997), a set of reference values that grew out of the periodic editions of the Recommended Dietary Allowances (RDAs) for nutrients over the previous 50 years. The RDAs and now the DRIs are to be used as reference values in food and nutrition policy and programs. Included in the DRI set of reference values is the category of Tolerable Upper Intake Levels (ULs), defined as the highest levels of nutrient intake likely to pose no risk of adverse health effects for almost all individuals in a specified life stage group. As