Glow sticks contain hydrogen peroxide, and phenol is produced as a by-product. Therefore, it is advisable to keep the mixture away from skin, and to prevent accidental ingestion, if the glow stick case splits or breaks. If spilled on skin, the chemicals could cause slight skin irritation, and swelling or, in extreme circumstances, cause vomiting and nausea. However, many ravers will cut or break open a glow stick and apply the glowing solution directly to bare skin in order to make their bodies glow. It has been said that glow stick chemicals cause cancer, although no research has suggested that they might. Also it is wise to avoid all contact with thin membranes such as the eye or nasal area. Despite reports to the contrary, it is not safe to smoke or ingest glowing phenol, and it will not produce any drug-like effects. The fluid contained in glow sticks can also dissolve some types of plastic.