In June, 2007, the US Food and Drug Administration and similar agencies in Panama, Puerto Rico and Australia advised consumers to avoid certain brands of toothpaste manufactured in China, after some were found to contain the poisonous diethylene glycol, also called diglycol or labeled as "DEG" on the tube. The chemical is used in antifreeze as a solvent and is potentially fatal.^[5]

Toothpaste is most commonly sold in flexible tubes, though harder containers are available. The hard containers stand straight up, availing more of the toothpaste and saving shelf space.
Active ingredients

Fluoride in various forms is the most popular active ingredient in toothpaste to prevent cavities. Although it occurs in small amounts in plants and animals, and has effects on the formation of dental enamel and bones, it is not considered to be a dietary essential and no deficiency signs are known. Sodium fluoride (NaF) is the most common form; some brands use sodium monofluorophosphate (Na₂PO₃F). Much of the toothpaste sold in the United States has 1000 to 1100 parts per million fluoride ion from one of these active ingredients, in the UK the fluoride content is often higher, a NaF of 0.32% w/w (1,450 ppm fluoride) is not uncommon. This consistency leads some to conclude that cheap toothpaste is just as good as expensive toothpaste. When the magazine Consumer Reports rated toothpastes in 1998, 30 of the 38 were judged excellent. Application of fluoride also prevents moisture build-up in some surfaces.^{[citation needed]}

Other ingredients are less commonly used, including Hydroxyapatite nanocrystals and calcium phosphate for remineralization,^[6] and strontium chloride or potassium nitrate to reduce sensitivity.

Other ingredients

In addition to fluoride, the other fundamental ingredient in most toothpastes is an abrasive.^{[citation needed]} Studies have shown that abrasives in toothpaste reduce the time needed to remove plaque from the teeth by approximately 50%. Abrasives, like the dental polishing agents used in dentist's offices, also cause a small amount of enamel erosion which is termed "polishing" action. Some brands contain powdered white mica which acts as a mild abrasive, and also adds a cosmetically-pleasing glittery shimmer to the paste. Many may contain frustules of dead diatoms as a mild abrasive. The removal of plaque and calculus prevents caries and periodontal disease. The polishing of teeth removes stains from tooth surfaces, but has not been shown to improve dental health over and above the effects of the removal of plaque and calculus.

Many, though not all, toothpastes contain sodium lauryl sulfate (SLS) or another of the sulfate family. SLS is found in other personal care products as well, such as shampoo, and is largely a foaming agent although it also acts as a powerful antimicrobial. Due to the anionic charge of SLS, mouthwashes containing cetylpyridinium chloride (which has a cationic charge and thus neutralises SLS) should not be used straight after brushing. SLS may cause a greater frequency of mouth ulcers in some people as it can dry out the protective layer of oral tissues causing the underlying tissues to become damaged[1].