The ingredients of Calgon® dual action tablets are shown in Table 1.
|PEG-130 - PEG-150|
Table 1: Ingredients of Calgon® dual action tablets
The ingredients of other formulations of Calgon®, such as that in Figure 15, can be found at the Reckitt Benckiser website.
Figure 15: One of the formulations of Calgon
PEG is short for polyethyleneglycol. This is a family of polymers with the formula HO(CH2CH2O)nH. They help bind together the ingredients into a tablet which does not crumble and also have the effect of reducing the formation of dust during manufacture.
Polyethyleneglycols are made from epoxyethane, which is in turn made from ethene by catalytic oxidation with the oxygen from air. Epoxyethane has the formula
The number after PEG is its approximate relative molecular mass. So PEG 200 has Mr = 200.
Sodium sulfate is added to Calgon® as a so-called filler. It does not have any water softening effect. It is used to bulk out the active ingredients so that it is easier to measure out the required quantity. So a spoonful, for example, might contain the correct amount of the active ingredients
In tablet formulations of Calgon®, cellulose is added. This swells when it is exposed to water and helps the tablet to break up when added to the wash.
Aqua is shorthand for water and colours are also added to make the product look attractive and distinctive.