What Is It?
Sodium Metaphosphate, Sodium Trimetaphosphate and Sodium Hexametaphosphate are all sodium polyphosphates made of repeating units of NaPO3. Sodium Metaphosphate generally refers to a long chain of NaPO3 units that is not soluble in water, which is why it is sometimes called insoluble metaphosphate. Sodium Trimetaphosphate has three NaPO3 units, and Sodium Hexametaphosphate has six NaPO3 units. Both the Trimetaphosphate and the Hexametaphosphate are soluble in water. In cosmetics and personal care products, Sodium Metaphosphate, Sodium Trimetaphosphate and Sodium Hexametaphosphate are used in the formulation of makeup foundations, mascara, bath products, and moisturizing and skin care products.
Why Is It Used?
Sodium Metaphosphate, Trimetaphosphate and Hexametaphosphate inactivate metallic ions so as to prevent the deterioration of cosmetics and personal care products. Sodium Metaphosphate is also used to polish the teeth, reduce oral odor, or otherwise cleanse or deodorize the teeth and mouth. Sodium Trimetaphosphate minimizes the change in the A measurement of the acidity or basicity of a substance. pH is the negative logarithm (base 10) of the concentration of hydrogen ions in solution. Water has a concentration of hydrogen ions of 1.0 x 10-7, and thus has a pH of 7. A pH of 7 is considered neutral, a pH lower than 7 is considered acidic, and a pH higher than 7 is considered basic. of a solution when an acid or a base is added to the solution and Sodium Hexametaphosphate prevents the corrosion (rust) of metallic materials used in packaging cosmetics and personal care products.
Sodium Trimetaphosphate, and Hexametaphosphate are all inorganic salts that are often referred to as glassy sodium polyphosphates. Sodium Metaphosphate, in the form of long chains, is referred to as insoluble metaphosphate.
The Food and Drug Administration (FDA) includes Sodium Metaphosphate and Hexametaphosphate on its list of substances considered Generally Recognized As Safe (“GRAS” is an acronym for the phrase Generally Recognized As Safe. Under sections 201(s) and 409 of the Federal Food, Drug, and Cosmetic Act (the Act), any substance that is intentionally added to food is a food additive, that is subject to premarket review and approval by FDA, unless the substance is generally recognized, among qualified experts, as having been adequately shown to be safe under the conditions of its intended use, or unless the use of the substance is otherwise excluded from the definition of a food additive.) for direct addition to food as sequestrants. Sodium Trimetaphosphate is permitted as a multipurpose additive in modified food A complex carbohydrate widely distributed among plants. It is the chief storage form of carbohydrates in plants. not to exceed 0.04% residual phosphate. The safety of these three ingredients has been assessed by the The Cosmetic Ingredient Review (CIR) was established in 1976 as an independent safety review program for cosmetic ingredients. The CIR Expert Panel consists of independent experts in dermatology, toxicology, pharmacolgy and veterinary medicine. The CIR includes participation by the U.S. Food & Drug Administration and the Consumer Federation of America. (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that Sodium Metaphosphate, Sodium Trimetaphosphate and Sodium Hexametaphosphate were safe for use in cosmetics and personal care products when formulated to avoid skin irritation.
CIR Safety Review: The CIR Expert Panel noted that only Sodium Hexametaphosphate was reported to be used. Although the typical concentrations historically have been less than 1% for these ingredients, higher concentrations have been used in products such as bath oils, which are diluted during normal use. Pure Sodium Hexametaphosphate was a severe skin irritant, whereas a 0.2% solution was only mildly irritating. A similar pattern was seen with ocular toxicity. These ingredients were not genotoxic in bacterial systems nor were they carcinogenic.
No reproductive or developmental toxicity was seen after exposure to Sodium Hexametaphosphate or Sodium Trimetaphosphate. In clinical testing, irritation was observed as a function of concentration; concentrations as high as 1% produced no irritation in contact allergy patients.
The CIR Expert Panel concluded Sodium Metaphosphate, Sodium Trimetaphosphate and Sodium Hexametaphosphate were safe for use in cosmetic products when formulated to avoid skin irritation.
Link to FDA Code of Federal Regulations for Sodium Metaphosphate, Sodium Trimetaphosphate, and Sodium Hexametaphosphate
Sodium Metaphosphate, Trimetaphosphate, and Hexametaphosphate may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.