Column 3: UN number refers to the UN Recommendations on the transport of dangerous
goods, Eleventh revision (1999). This is given only for active ingredients in Tables 1, 2, 3
or 4, since so few ingredients in Table 5 have UN numbers. The UN number refers only to the
active ingredient; formulations are likely to have different numbers, since the ingredient may,
for example, be dissolved in a solvent - and liquid products have different UN numbers, which
depends on their flammability.