Towards an alternative criterion for the shipping safety of activated carbons: Part 4. The role of times to ignition

To the previously developed and implemented new criterion for the shipping safety of activated carbons is added a consideration of ignition times. It is shown that there is considerable support for the view that in the past shipments of such materials deemed on the basis of the IMCO/ISO test procedures to be subcritical have actually been supercritical, but that the long ignition times, exceeding voyage times, have prevented fire from developing.