“Trace contaminant” and “background level” are not precise terms.
Claims often need to be based on specific substance-bysubstance assessment to demonstrate that the level is below that causing harm. Also, the exact definition of trace contaminants may depend on the product area concerned. If the substance is not added intentionally during processing, and manufacturing operations limit the potential for cross-contamination, a claim such as “no intentionally added xx” may be appropriate.
However, if achieving the claimed reduction results in an increase in other harmful materials,the claim may be misleading.