At-home treatments include desensitizing toothpastes or dentifrices, potassium salts, mouthwashes and chewing gums. Therefore, fluoride mouthwashes, toothpastes, gels and varnishes can help to reduce the prevalence of caries. Chelated zinc is used in toothpastes and mouthwashes to prevent bad breath. In pharmacy, myrrh is used as an antiseptic in mouthwashes, gargles, and toothpastes. Many herbal toothpastes do not contain fluoride or sodium lauryl sulfate. Sanguinaria (Bloodroot) is a herbal extract which is included in some toothpastes and mouthwashes. Some of these toothpastes contain peroxide, the same ingredient found in tooth bleaching gels. Tooth whiteners in toothpastes work through a mechanical action. It may be found in most whitening toothpastes. Papain is added to some toothpastes and mint sweets as a tooth whitener. Strontium chloride is sometimes used in toothpastes for sensitive teeth. The abrasive in these toothpastes, not the peroxide, removes the stains. Disodium pyrophosphate is used as a tartar control agent in toothpastes. Fluoride was first added to toothpastes in the 1890s. Fluoride toothpastes developed in the 1950s received the ADA's approval.