A set of 10 environmental impact indicators is proposed for the evaluation the environmental impact of industrial installations and processes or industrial companies and sites: global warming, destruction of the ozone layer (ozone depletion), acidification, photochemical ozone creation, human toxicity, ecotoxicity, eutrophication, resource consumption (abiotic depletion), water consumption and waste production. These are "weighed" indicators: the individual emissions or discharges of components contributing to a certain theme are multiplied with a weighing factor and aggregated. Eco-efficiency indicators are calculated by dividing the "weighed", indicators by a value related to production. These relative indicators make it possible to quantify the evolution of the environmental performance for a process, company or industrial site and to evaluate which component(s) contribute(s) most to a given theme, thus allowing to set priorities for lowering the environmental impact. Examples illustrate the proposed method. Attention is also given to the emission of persistent organic pollutants (POPs) during the incineration of waste, trying to answer the question: are waste incinerators sinks or sources of POPs? It is shown that for non-carcongenic effects according to the incineration scenario, the weighed input/output ranges from 0.3 to 20,500 when considering the POPs in flue gases and solid residues.