4.2 Heavy metals
Toxic metals found in herbal raw materials include lead (Pb),
cadmium (Cd), mercury (Hg) and arsenic (As). Regulation (EC)
No. 629/200840 sets maximum levels in the EU for Pb, Cd and Hg
in food supplements. For most commercialized herbs these
maximum levels can be observed. Higher levels may exceptionally
be acceptable provided that product safety is assured.41,42
Suitable measurement methods in herbal raw materials are
provided in the European Pharmacopoeia:43 atomic absorption
spectroscopy (AAS) and inductively coupled plasma (ICP)
techniques are the methods of choice in the herbal industry.14