Division SPo 4

The container must be opened outdoors and in dry conditions.

The phrase shall be assigned to plant-protection products containing active substances which may react violently with water or damp air, such as aluminium phosphide, or which may cause spontaneous combustion, such as (alkylenebis-) dithiocarbamates. This phrase may also be assigned to volatile products classified with R20, 23 or 26. Expert judgement must be applied in individual cases, to assess whether the properties of the preparation and the packaging are such as to cause harm to the operator.