Answering to a Prosecuting Council request, CETESB-Environmental Protection Agency for the State of Sao Paulo, Brazil, developed the above proposal, which aim is to have the valuation for damages caused by petroleum and its derivatives spill on the sea. The proposal criterium takes into account the quality of oil spilled, the affected area sensibility, the product toxicity, the product persistence in the environment and the organism mortality. There is a mathematical formula through which it is possible to value the amount to be paid by the polluter. (author). 16 refs., 2 figs., 8 tabs.