| Description | Talcum is a powdered, selected natural hydrated magnesium silicate, light, homogenous, white or almost white powder, greasy to the touch (non abrasive) |
| Solubility | Practically insoluble in water, in ethanol (96%) and in dilute solution of acids and alkali hydroxide |
| Identification | |
|
A) Chemical Test
C) Chemical Test |
A) As per BP B) A white srystalling precipitae of magnesium ammonium phosphate is formed. C) Within a short time, a white ring is rapidly formed around the drop of water |
| Acidity or Alkalinity | NMT 0.4 ml of 0.01 hydrochloric acid to change the colour of indicator to green. 2) NMT 0.3 ml to 0.01 sodium hydroxide to change the color of indicator to pink |
| Iron | NMT 0.25% |
| Aluminium | NMT - 2% |
| Water Soluble Substance | NMT - 10mg (0.2%) |
| Calcium | NMT 0.9% |
| Lead | NMT 10 ppm |
| Magnesium | 17.0 to 19.5 % |
| Loss on Ignition | NMT - 7.0 % |
| Microbial Contamination | (Tropical administration) The total viable
aerobic count is NMT 100 aerobic bacteria and
fungi per gram. (Oral administration) The total viable aerobic count NMT of 1000 aerobic bacteria and NMT 100 fungi per gram |
| Asbestos | Talc should be free from tremolite and chrysotile form of asbestos. Investigation by X-Ray diffraction for amphiboles and serpentines. |