Life after phosphates: a new
generation of detergent builders
For 4,000 years we cleaned things with soap. About
a half century ago, a major advance in cleaning tech-
nology was achieved with the discovery of detergent
builders. The ability of detergent builders to chelate (tie
up) water hardness ions with condensed phosphates
was spectacularly successful—and that had the usual
effect. We used phosphates in large enough quantities
that we drew attention to their inevitable drawbacks.
Phosphorous is an essential nutrient for all life, and it
was believed that phosphates entering our waterways
were enabling excessive algal growth and premature
eutrophication of lakes. Phosphates from detergents
never amounted to more than 20% of the entire phos-
phorous load, but it was easier to ban or limit phospho-
rous in detergents than to ask people to stop fertilizing
their lawns or flushing their toilets.
The process of eliminating phosphates from detergents was slow.
They disappeared first from product groups which had less need for strong
chelants, such as laundry detergents. Applications demanding strong chelation of hardness ions, notably machine dishwashing, have only recently
been forced to find alternative builders. There are a few remaining pockets where small quantities of phosphates are still used in detergents,
but these industries are too small to have yet attracted much attention.
The loss of detergent phosphates proved to be both scary and exciting, in equal measure, for chemical manufacturers and formulators. It
was scary to lose an important detergent ingredient but was, and is, exciting to be presented with the opportunity to discover new molecules and
learn how to use them.
Formulation Science is a regular Inform column highlighting
advances, trends, and challenges in cleaning product formulation.