WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues; 2007

The objectives of these guidelines are to provide:

• guiding principles for assessing the quality in relation to the safety of herbal medicines, with specific reference to contaminants and residues;
• model criteria for use in identifying possible contaminants and residues;
• examples of methods and techniques; and
• examples of practical technical procedures for controlling the quality of finished herbal products.