As a strategy of PESGRI99, and in order to comply with the hierarchy of waste management
principles approved at the European Union level- resolution of the European Union Council of Ministers
of the Environment nrº 97/076/01, it was elaborated a National Plan for Industrial Waste Prevention
(PNAPRI) [10]. PNAPRI was a plan for the period 2000-2015 in order to comply the hierarchy of waste
management, creating structures such that the waste of certain activities could be used as raw material in
other activities. The main goal was to reduce the quantities and the toxicity of industrial waste including
the energy valuation. It was also elaborated 21 technical guides containing a wide range of information
particularly on prevention technologies and/or measures potentially suitable for the production process of
each of the industrial sectors.