Several large agrochemical companies have successfully employed the BBE algal cuvette monitor, to assist with their toxicity assessment programmes. Applications have included the measurement of algal populations in artificial test ponds, subjected to doses of new products, and the assessment of production centre effluents for potential toxic effect on the receiving water course or sewer, the latter being done by measuring the suppression of activity of single class algal cultures. In both cases the decisive advantages were: speed, low operating cost, low skill requirement and low capital investment.

Predicting the effect of toxic substances on living organisms is extremely difficult since this is effected by the complex environmental situation. Even substances having a direct and immediate effect cannot be directly detected but have to be interpreted by the reaction of the organism effected. It is generally accepted that the effect of toxic substances on respiration rate of bacteria when monitoring waste water is a useful indicator especially because of the rapid response. However factors such as changing substrate and biological adaption need to be accounted for. Experience within the chemical industry of the use of such on-line Toxicity monitors is described, in particular in conjunction with automatic divert to a balancing tank.