Toxicology being an inter-disciplinary science, an understanding of the physiology, biochemistry, pathology, endocrinology, pharmacology, clinical pharmacology, genetics, etc., is a must in order to make an integrated assessment of findings of toxicology studies and to identify potential signals from the clinical studies. Masters or PhD degree in the area of toxicology, veterinary medicine, human medicine, pharmacology etc. represents a relevant qualification that teaches these subjects. The depth and breadth of toxicology subjects covered in these courses vary. Certification by professional bodies in the field of toxicology is an endorsement of a person’s relevance of qualification and experience in the field of toxicology. Some of these certifications are based on successful completion of a written examination (ex: Diplomate of American Board of Toxicology), while others may be based on relevance of qualification and demonstration of actual practice of toxicology, and adequacy of experience in the toxicology field (ex: European Registered Toxicologist). In summary, the most critical attribute that a person should process in order to be able to derive a PDE is combination of relevant educational qualification, understanding of basic science of toxicology, and adequate experience in the field of toxicological risk assessment.