Products
Talc is available as an open product in pharmacies and drugstores. It is a common ingredient in powders and is included in shake brushes and mixtures such as white shake mixture. Talc is an excipient for many drugs, especially tablets, and it is also used in cosmetics.
Structure and properties
Talc exists as a light, white to almost white, homogeneous, greasy to the touch, odorless and tasteless powder that is practically insoluble in water and dilute acids. It is a selected, powdered, natural and hydrous magnesium silicate. Talc consists of the elements magnesium, silicon, oxygen and hydrogen. Talc can contain different amounts of associated minerals, for example chlorite, magnesite, calcite and dolomite. It is the main component of soapstone. The pharmacopoeia stipulates that the mineral must be free of asbestos, which is known to be carcinogenic. Talc has a high melting point of over 1300 °C and the density is over 2.5 grams per cubic centimeter.
Effects
Talc has drying, water-binding, skin-conditioning, lubricating, and adsorbing properties. It is chemically unreactive. Talc provides a soft skin feel, reduces friction and prevents skin rashes.
Fields of application
- For the preparation of powders and powder mixtures, which are applied to the skin.
- As a pharmaceutical excipient, talc is used, among other things, as a superplasticizer and as a lubricant in the production of tablets.
- For the treatment of skin diseases, against excessive sweating.
Dosage
According to the professional information. When decanting, for example in pharmacies and drugstores, respiratory protection should be worn to avoid inhalation. Dust formation should be avoided. Alternatively, work should be done under a fume hood.
Contraindications
Talc should not be inhaled and should not get into the eyes. Do not allow children to play with powder doses. Refer to the drug label for complete precautions.
Adverse effects
Talc is no longer recommended for wound treatment because granulomas may form and drying of the wound is not in accordance with the latest findings. Furthermore, it may be microbially contaminated if not sterilized. Talc should also no longer be used for the care of the diaper area of infants and young children, because accidental inhalation of larger quantities, for example, during spillage, can lead to coughing, severe respiratory disorders and lung damage in children. The mineral is insoluble in water and difficult to break down in the body. Talc has been linked to the development of cancer, especially when contaminated with asbestos. One example is the development of malignant mesothelioma of the pleura. Talc for pharmaceutical use may not contain asbestos (see above). Whether talc without asbestos can cause cancer is disputed and not conclusively clarified. Possible impurities, for example in personal care products, are problematic. In the USA, baby powder manufacturer Johnson & Johnson is facing thousands of lawsuits from women with ovarian cancer who had regularly used the powder for intimate care. In one of those lawsuits, the company was ordered to pay $4.7 billion to 22 women. In 2020, the company stopped selling the well-known powder in the U.S. and Canada, but not in many countries and elsewhere. The company is vehemently defending itself against the allegations and managed to win some court cases.