Stora Enso's production processes generate various wastes, the vast majority of which are reused as residuals. Such materials include biomass fibres, ash from energy production, lime solids from pulping processes, and wastewater treatment sludge. Many of these materials are used for our internal bioenergy production, or for agricultural purposes, brick manufacturing and road construction by our stakeholders. We are constantly looking for new and innovative ways to reuse materials that would otherwise end up as wastes. In 2013 the Group's revenues from these residuals amounted to EUR 11 million.
In our Global Responsibility Strategy and on the basis of our review of our Key Performance Indicators (KPIs) we have decided to discontinue our previous target on waste to landfill, but instead to focus on improving material efficiency as a broader concept. This concept covers waste reduction, the efficiency of our use of raw materials and energy, and business value created from materials currently considered as waste. During 2014 we will continue to develop this concept and the ways we can measure our material efficiency. We will also carry on compiling waste to landfill figures as a performance indicator and continue to report these figures annually in this report.
Hazardous wastes from our production include used oils, solvents, paints, laboratory chemicals and batteries. In 2013 Stora Enso's production units created a total of 2 859 tonnes of hazardous waste, down from 4 444 tonnes in 2012.
We dispose of hazardous wastes by ensuring that they are safely processed at hazardous waste facilities or incinerators. We report on our disposal of hazardous wastes in line with definitions set out in respective national regulations. No significant spills, releases or leakages of hazardous wastes occurred in 2013.