Pyrrolizidine alkaloid contamination in herbal medicinal products: Limits and occurrence

Since 2013, a potential contamination of medicinal plant material with pyrrolizidine alkaloid-containing weeds e.g. Senecio has been discussed. The knowledge about such a risk of contamination induced suppliers of medicinal drugs and manufacturers of medicinal teas to investigate the situation regarding herbal drugs and teas and other medicinal products of plant origin. As due to worldwide cultivation/collection and season-dependent sourcing processes an immediate elimination or even reduction of PA contamination at all sourcing sites was considered impossible, manufacturers have taken action by application of their Code of Practice, by monitoring pyrrolizidine alkaloid contamination and by collection of data, by elimination of peak exposures as well as by participation in research projects. The Herbal Medicinal Products Committee at the European Medicines Agency recommended a transitional limit of 1.0 μg pyrrolizidine alkaloids per day related to the final product for three years which has recently been prolonged by a further two years. Against the background of the assessment of the European Food Safety Authority, the option of establishing a permanent limit of 1.0 μg per day should be taken into consideration during future discussions.