A.
DGR 8.1.6.9.2 Step 6 (c) is the rule to follow when entering the quantity of residue dangerous goods of UN 3363 Dangerous Goods in Apparatus or Machinery.

The rule says: ?gthe individual total quantities of dangerous goods in solid, liquid or gaseous state, contained in the article must be shown?h. Therefore, the quantity to be shown is the total net quantity of each physical state individually. It is not the Gross Weight including the weight of the article and packagings.

A statement such as the quantity cannot be measured is unacceptable. Even if it is an approximate estimated amount, the net quantity of the dangerous goods must be shown. A shipper must not tender a shipment of which he does not know the quantity of dangerous goods.