Quantity of Dangerous Goods

Gravity at a macroscopic level.
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 Mass and Weight

Mass and weight are two different things though the word weight is used many occasions in the place of mass. Every object has a mass. It never changes. An object having a mass of 50 Kg will have the same mass whether it is on the surface of Earth or Moon.

Weight is used to describe the mass of the body or the force of the gravity acting on it. Actually weight is the measure of gravitational force acting on the object at a specific location. Tthe object with the mass of 50 kg will have the weight of 50 kgf on the surface of the Earth but only 8.5 kgf on the surface of the moon.

Effects by change of gravity

Now we know that change of gravity will have dynamic effect on the weight.  A shipping container falling downwards with an acceleration force greater than 9.8m/sec will make the mass weight less. However move the container at same speed upwards will make the weight of the mass double.

During ocean passage the movements of the vessel will make considerable changes to the weight of the cargo within the containers.

A well secured cargo in container not only minimizes cargo damage and claim but will drastically minimize hazard due to shifting of cargo or leakage which can be fatal in case of dangerous goods.

Vessel’s motions at sea

What shall be declared for dangerous goods?  Mass? Weight? Net or Gross?

Quantity of Dangerous goods shall be declared by volume or mass as appropriate.

Gross mass              = mass of dangerous goods and package

Net mass                  = mass of dangerous goods

In IMDG Code whenever the mass of a package is mentioned, the gross mass is meant. However this does not include mass of tanks and containers.

Example of declaration

UN 1263 PAINT class 3 PG III (24 Deg C.c.c)  1 x steel drum 100 kg

UN 1263 PAINT class 3 PG III (24 Deg C.c.c)  1 x steel drum Gross mass 100 kg net mass 93 kg

Filling of packages

While filling of packages the quantity allowed is given in volume or by mass in IMDG Code. See example packing instruction below.

For gas it is altogether different case because there we deal with pressure 🙂

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  1. For exemple in ADR, sometimes (and for the exemple of UN 1263 Paints) the most correct is to use the volume (L), because are liquids. I don’t like, but is the only way to verify the aplicability of exceptions acccording with, related with to quantities carried per transport unit…

  2. In of ADR say:

    – For articles, gross mass in kilograms;
    – for articles of Class 1, net mass in kilograms of the explosive substance;
    – for dangerous goods in machinery and equipment specified in Annex A (Parts 1 – 7), the total quantity of dangerous goods contained there, in in kilograms or litres as appropriate;
    – For solids, liquefied gases, refrigerated liquefied gases and dissolved gases, net mass in kilograms;
    – For liquids, the total quantity of dangerous goods contained in litres;
    – For compressed gases, adsorbed gases and chemicals under pressure, the water capacity of the receptacle in litres.

  3. Hi, ADR gives these information to calculate the permitted quantity for exemption of placarding, safety equipments, …
    But this has nothing to do with the manner to declare quantities on the transport document.
    According to 5.4.1, as in the IMDG code, quantities may be net or gross (except speficic cases as explosivises).
    and the way to indicate exemption is to additionnally give the “quantity” of units loaded per catogory (0 to 3).
    For exemple 50 liters of Paint , 3 II may be declared :
    Paint UN 1263, 3, II 75 kg gross mass, cat. 2 : 50

    Also, concerning IMDG, many companies require number and quantity of inner recepacles for combined packages.
    This is not required by IMDG Code, but use of certains softwares led to this requirement by companies. Although softwares has been amended to make this requirement not mandatory, a lot of companies continue to ask for, enabling them some controls…
    Best regards

    1. Antoine ,
      Many thanks for your comment which adds value to this discussion. I do agree with you that many shipping lines, because of over dependency on software fields, insist for non mandatory information which leads to delay and confusion. Certain shipping lines are providing dangerous goods declaration with fields to fill up with options such as
      Marine Pollutant YES/NO
      Limited Quantities YES/NO
      Excepted Quantities YES/NO

      And shippers fill up as Y or N which enable the booking staff of shipping line to update radio button or dropdown options of their in house software which is a clear violation of IMDG Code Chapter 5.4.

      I once again thank you for your feedback. I am traveling this week for a town hall session and a conference will be back next week interpreting some other provision of IMDG Code. Your suggestions are always welcome.


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