Cetylpyridinium chloride is a cationic quaternary ammonium compound in some types of mouthwash such as Crest Pro-HealthÂ®, ScopeÂ®, Reach ACTÂ®, CepacolÂ®, ViadentÂ®, OasisÂ®, Dr. FreshÂ®, swishÂ®, BreathRXÂ®, and BetaCellÂ®, toothpastes such as Crest SensitivityÂ® and Crest Plus ScopeÂ®, CepacolÂ® lozenges and throat sprays, anti-snore throat sprays (Breathe RightÂ®, Rite Aid, CVS, Walgreens, etc.), OasisÂ® moisturizing mouth spray, BreathRXÂ® breath spray, and SinoFreshÂ® and Ayr No-Drip SinusÂ® nasal sprays. It is an antiseptic that kills bacteria and other microorganisms. It has been shown to be effective in preventing dental plaque and reducing gingivitis. It has also been used as an ingredient in certain pesticides. However, this ingredient has also been shown (according to WebMD, eMedicine, and Amazon.com and Drugstore.com reviews of Crest Pro-HealthÂ® rinse product) to cause brown stains between the teeth. Source:http://en.wikipedia.org/wiki/Cetylpyridinium_Chloride Antiseptic agent is a substance which kills or inhibits the growth of disease-causing bacteria and other microorganisms. It is essentially nontoxic to to be applied to the skin or mucous membranes. (Disinfectant including cresol, bleaching powder, and phenol is in general toxic to cells of the body). Common antiseptic agents are Benzalkonium Chloride, Cetrimide, Chlorhexidine, Hexachlorophene, Iodine Compounds, Mercury Compounds (Thimerosol), Alcohol and Hydrogen Peroxide, Hexamine Hippurate, Triclosan, Cetylpyridinium Chloride, And Dequalinium. Other substances which can be used for antiseptic purpose include Boric acid and volatile oils such as Methyl Salicylate.