ABSTRACT
Aromatic materials are potentially hazardous but their informed use determines the exposure dose and therefore the degree of safety or hazard involved. Paracelsus regarded as the ‘father of pharmacology’, comprehensively used natural compounds in the treatment of disease. The safety of essential oil use is a topic that generates much debate and is on occasion subjected to inaccurate use of data. The chapter discusses special attention to the conditions where the topical application of aromatherapy formulations may be harmful. Environmental conditions such as humidity and season have also been shown to have some influence. Intra-individual variations in skin irritation responses can also occur. Sensitive skin is defined as a subjective cutaneous hyperactivity to environmental factors and approximately 40% of the population consider themselves to have the condition. Clinical symptoms may develop within minutes and include oral and pharyngeal pruritus and ‘tingling’, a sensation of tightening of the airways, colicky abdominal pain, nausea, vomiting, cutaneous flushing, urticaria and angioedema.
