Phosphonate
Present in very small amounts and doing two quiet jobs: holding back scale, and stopping trace metals from destroying the bleach.
In detail
A phosphonate is an organic molecule carrying phosphonic acid groups, and in a cleaning product it is a sequestrant used at low concentration. It binds calcium and magnesium, which slows the formation of scale on heating elements and in machines. More specifically, it binds transition metals such as iron, copper and manganese. That second function matters more than its concentration suggests. Traces of those metals catalyse the decomposition of hydrogen peroxide, so a bleach-containing product without a stabiliser can lose much of its oxidising power in the box or in the water before it ever reaches the stain. A phosphonate keeps the metal ions out of circulation and the bleach intact. Declared on a label by class and weight band above 0.2%.
Why
- Phosphonate is explained by Chelation
- Phosphonate is explained by Oxidation and bleaching
Sources for this page
Sources
Regulation (EC) No 648/2004 on detergents, Annex VII — labelling and ingredient data sheet
European Parliament and Council, as retained in UK law (legislation.gov.uk), 2004 · Government or regulator
Relied on for: That the class is one of the constituents a detergent label must declare, in weight bands above 0.2%. (states this directly)
Verification: a person has read the passage relied on.
Read on — Annex VII section A, the weight-range list and the declare-regardless list. Supports the claim as stated. Enumerates the ingredient-class family completely, and supplies the vocabulary a reader is actually confronted with on the back of a bottle.
Handbook of Detergents (Surfactant Science Series)
CRC Press / Taylor & Francis · Reference work
Relied on for: That phosphonates are sequestrants used at low concentration to control scale and to stabilise peroxide bleach against catalytic decomposition by transition metal ions. (background and mechanism only)
Verification: the work exists and is described correctly. Nobody has yet read the specific passage.
Last reviewed by a person on .