According to Directive 1999/31/EC, "inert waste" means waste that does not undergo any significant physical, chemical or biological transformations. Inert waste will not dissolve, burn or otherwise physically or chemically react, biodegrade or adversely affect other matter with which it comes into contact in a way likely to give rise to environmental pollution or harm human health.

In practice, and according to the modified Grand-Ducal regulation of 24 February 2003 concerning the landfill of waste, waste that can be considered inert waste is
- made up almost entirely of natural soil and rock resulting from their extraction during construction work;
- resulting from road works and of a mineral nature;

• from construction, renovation or demolition sites, which are mainly of a mineral nature. One condition is that the inert waste is not contaminated by hazardous substances or other potential nuisance generators.

Description copied from catalog.inspire.geoportail.lu.