When utilized properly, menthol crystals are relatively safe. Low concentrations of menthol are permitted in food, cosmetics, and even pharmaceuticals. However, skin and eye irritation may occur from direct contact with high-concentration menthol crystals. Also, inhalation of large amounts of menthol vapor may cause respiratory discomfort. Excessive ingestion can lead to gastrointestinal problems. Notably sensitive individuals, such as children, require special care in formulations. Safety limits on menthol concentration for various applications are controlled by regulatory bodies to ensure safety, and risk of exposure is only possible with improper handling and storage.