To ask the Secretary of State for Environment, Food and Rural Affairs when she expects to publish guidance (a) defining corrosive materials in a landfill environment and (b) defining the waste treatment requirements of article 6a of the Council Directive 1999/31/EC. 
Corrosive materials were banned from landfill with effect from 16 July 2002. The Landfill (England and Wales) Regulations 2002, that implement the Landfill Directive (Council Directive 1999/31/EC) in England and Wales, define waste as corrosive
Those Regulations define treatment, as referred to in Article 6a of the Directive, as meaning"if it consists of substances and preparations which destroy living tissue on contact".
Extensive guidance on all aspects of the Landfill (England and Wales) Regulations 2002 is available on the Environment Agency website."physical, thermal, chemical or biological processes (including sorting) that change the characteristics of waste in order to reduce its volume or hazardous nature, facilitate its handling or enhance recovery".