Federal, state and territory environment ministers haven't committed to a national air quality limit for ultra-fine particles, and won't yet consider controls on off-road diesel exhaust.
Federal, state and territory environment ministers will meet in Canberra next Tuesday to discuss issues including regulatory reform, climate change, air quality and packaging.
Environment Minister Greg Hunt says dealing with particle pollution and smog precursors will be key components of a national clean air plan to be finalised by mid-2016.
Senior environment department officers have confirmed they don't know when or if the national clean air plan will be finalised nor can they say when the long-awaited regulatory impact statement on packaging waste is likely to be released.
Environment Minister Greg Hunt has postponed next Thursday's meeting of environment ministers, which was scheduled to consider matters including a container deposit scheme.