Soap is designed as a product to be used once then flushed down the drain, so as expected the
environmental implications of its manufacture are not nearly so great as many other chemical
processes. There are two main areas of concern: the safe transport and containment of the
raw materials, and the minimisation of losses during manufacture.
The three main components of soap by both cost and volume are oils, caustic and perfumes.
Oils and perfume are immiscible in water and if spilled create havoc, although the oils do
solidify at room temperature. Transport of these products is by trained carriers, and the
systems for pumping from the truck to storage tanks is carefully designed. Perfumes are
bought in lined steel drums which are quite robust, and flammable perfumes are not used in
soaps.
All storage tanks are surrounded by bunds to catch the contents of a tank should it rupture or
a valve fail. When the storage system is designed, all the safety features (such as access to
tank and valves) are designed in, as well as procedures to deal with the product should it end
up in the bunded area.
Within the plant, all the process areas are also bunded, and the trade waste from there piped
to an interception tank before draining to the council’s trade waste system. The contents of
the interception tank are continuously monitored for acidity or alkalinity, and is designed to
settle out excess solids or light phase chemicals. If a spill is detected in the plant itself, a
portion of the interception tank can be isolated off and the effects of the spill neutralised
before the waste is dumped.
In most cases, however, potential problems are identified and stopped before they happen.
Often an off-spec product can be reprocessed and blended rather than dumped, and even
washout water can be reprocessed to minimised the discharges from the plant.
Finally, the manufacturing process itself is closely monitored to ensure any losses are kept to
a minimum. Continuous measurements of key properties such as electrolyte levels and
moisture both ensure that the final product is being made to spec, and ensures the
manufacturing process is working as it was designed to. Hence the losses in the plant will
indirectly be minimised because the process itself is being monitored.