Organophosphates used as flame retardants, plasticisers and lubricants such as tris-(2-chloro-, 1-methyl-ethyl)-phosphate (TCPP), tris-(2-chloroethyl)-phosphate (TCEP) or tris-(2-chloro-, 1-chloromethyl-ethyl)-phosphate (TDCP), tri-n-butylphosphate (TnBP), tri-iso-butylphosphate (TiBP), triphenylphosphate (TPP) and tris-(butoxyethyl)-phosphate (TBEP) have been analysed in several rivers and sewage treatment plant (STP) effluents. The concentrations in the River Ruhr are 20-200 ng/l TCPP, 13-130 ng/l TCEP, about 50 ng/l TDCP, 10-200 ng/l TBEP and up to 40 ng/l TPP. The STP effluents exhibit concentrations up to 400 ng/l TCPP, 130 ng/l TCEP, about 120 ng/l TDCP and 500 ng/l TBEP, respectively. The main sources for the load of organophosphates are sewage treatment plants, but not all contribute equivalent to the amount of inhabitants they serve.