Working together for a Safer World

Oxidising Solids – UN Test O.1

Transportation Classification Testing


UN Manual of Test & Criteria UN Test O.1 / CLP / GHS


The test is conducted primarily for the purposes of transportation. Mixtures of a reference oxidiser (potassium bromate) / cellulose (fuel) and mixtures of the substance and cellulose (fuel) to be tested are prepared in specified ratios. Using a conical funnel the mixtures are formed into a truncated conical pile, covering a looped ignition wire resting on the low heat conducting plate.

Power is applied to the ignition wire and is maintained for the duration of the test. The recorded burning time is taken from when the power is switched on, to when the main reaction (e.g. flame, incandescence or glowing combustion) ends. The test is performed five times on each substance to cellulose ratio and five tests are performed with each reference mixture ratio required to make a Packing Group assignment or to determine if the substance should not be classified in Division 5.1.

The test method is identical to that detailed within CLP/GHS regulatory procedures and therefore data gathered can be used for both applications.


Materials that are being classified for transport as an oxidising solid, based on either guess work or comparative studies are often incorrect and the large costs associated with classified oxidising materials can be avoided. Because a product, contains a known oxidising constituent, doesn’t simply mean the blend should also be classified.