(I) The principal task of a shampoo is to clean the hair.
(II) For that purpose, shampoo contains surface-active
substances, so-called surfactants, that become
attached to the water-insoluble dirt and fat deposits in
the hair. (III) Subsequently, they are washed away again
with water when the hair is rinsed and shampoo
removed. (IV) Sodium laureate sulphate is what makes
the shampoo foam. (V) We should, however, be careful
about removing too much fat from the hair because the
fatty substances also have a protective function.