Mercury (Hg)

We all know mercury is a silvery metal in liquid form. Probably most of us first saw it in childhood at the mirror like shining bulb end of thermometer when doctor pushed the thermometer in to our mouth .

In ancient days mercury was thought to have medicinal properties which will prolong life !! 🙂 Qín Shǐ Huáng Dì, Emperor of China, died due to  drinking a mercury and powdered jade mixture formulated by Qin alchemists thinking he will attain immortality. The Emperor’s tomb contained flowing mercury models of rivers in china. Ancient Egyptians and Greeks used mercury in cosmetics and other ointments.

Mercury is highly corrosive to aluminium and is classified as Corrosive Substances (Class 8) in model regulations. Recent study of corrosive effect of Mercury on Aluminium states that  heavy and sudden corrosion will take place leading to pitting and cracking which increases by presence of humidity. On mild steel the corrosion rate is.25mm/year.

Mercury is traditionally sold in flasks measuring about 2.5 litres (34.5 kg or 76 lb.). This weight is equal to one Spanish quintals; Spain was one of the biggest producers of mercury. Mercury is having high density of 13.54562 g/cm3

For sea transport IMDG Code list mercury under UN 2809 MERCURY Class 8 with special instruction prohibiting transport by hovercraft and other ships constructed of aluminium.  IMDG Code allows flasks up to 3L for transporting Mercury by sea, including the empty flask the total gross mass per flask may be around 45-50 kg.

There is a new convention by United Nations named Minamata Convention for protecting human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds.

Mercury Flask
Mercury Flask
Overpack containing Mercury
Overpack containing Mercury

If you are shipping Mercury or any article containing Mercury by Sea it is a mandatory requirement that you receive training to handle same as per IMDG Code.

For details of training click here  Click here for Elearning

UN Package Markings & Tests

Jerrycans.
Jerrycans

Packaging means one or more receptacles and any other components or materials necessary
for the receptacles to perform their containment and other safety functions
.

Package means the complete product of the packing operation, consisting of the packaging and its contents prepared for transport.

Below is for beginners to understand what do Packing Codes means and why do some shipping lines or freight forwarders ask for it.

As per IMDG Code the design of each packaging used for carriage of Dangerous Goods shall pass  UN Performance testing. (Consignments of Dangerous goods in limited quantities does not require this ) Details of performance test for various types of packaging are laid out in Chapter 6 of IMDG Code.

After the performance test a unique marking will be issued by the testing authority which shall be durable and legible.

If the packaging is intended to carry gross mass of more than 30 Kg of then this marking is required to be on the top or on the side of the packaging.

For Packaging of more than 30 kg the letters, numerals and symbols shall be at least 12mm high.

For Packaging of 30 kg, 30 l or less the letters, numerals and symbols shall be at least 6mm high.

For Packaging of 5kg, 5 l or less the letters, numerals and symbols shall be of appropriate size.

Packaging Marks

Each package design type is tested and issued with a unique mark from which we can understand the type of package and certain other details.

The code consists of:
.1 an Arabic numeral indicating the kind of packaging, such as drum, jerrican, etc.,
followed by

.2 one or more capital letters in Latin characters indicating the nature of the material,
such as steel, wood, etc., followed where necessary by

.3 an Arabic numeral indicating the category of packaging within the type to which the
packaging belongs.

Kind of Packaging

1 Drum
2 (Reserved)
3 Jerrican
4 Box
5 Bag
6 Composite packaging

Types of material:
A Steel (all types and surface treatments)
B Aluminium
C Natural wood
D Plywood
F Reconstituted wood
G Fibreboard
H Plastics material
L Textile
M Paper, multiwall
N Metal (other than steel or aluminium)

Lets look at an example package marking and interpret same to understand how this works

image

Letters UN = United Nations Symbol

4G = Packaging Code ( 4= box , G = Fibreboard )

Y = Tested for packing group II

145 = Maximum gross mass in Kilogram

S = Packing intended to carry solids or inner packing

02 = Last two digits of the year in which packaging was manufactured

NL = The country authorizing the allocation of this mark

VL823 = Manufacturer’s details

Testing

These design types  of packaging undergo various types of test as required by the IMDG Code. Lets look at some of the test requirements

Drop test for Bag

Packaging No. of test samples Drop orientation
Bags – single-ply with a side seam Three
(three drops per
bag)
First drop: flat on a wide face
Second drop: flat on a narrow face
Third drop: on the end of the bag
Bags – single-ply without a side
seam or multi-ply
Three
(two drops per bag)
First drop: flat on a wide face
Second drop: on an end of the bag

Drop height

Packing group I

Packing group II Packing group III
1.8m 1.2m 0.8m

if the substance  to be carried have a relative density more than 1.2 then the drop height is calculated as

dx1.5m , dx1.0m & dx0.67m for packing groups I,II and III respectively.

Leakproofness test

Any packaging intended to carry liquids shall undergo leakproofness test. These packaging will be kept under water and internal air pressure is applied

Packing group I

Packing group II Packing group III
Not less than
30 kPa (0.3 bar)
Not less than
20 kPa (0.2 bar)
Not less than
20 kPa (0.2 bar)

After conducting various test, as specified in chapter 6 of IMDG Code on successful pass a certificate will be issued by the testing authority to the manufacturer of packaging with below mandatory details

  1. name and address of the test facility;
  2. name and address of applicant (where applicable);
  3. a unique test report identification;
  4. date of the test report;
  5. manufacturer of the packaging;
  6. description of the packaging design type (such as dimensions, materials, closures,
    thickness, etc.), including method of manufacture (such as blow-moulding), and which
    may include drawing(s) and/or photograph(s);
  7. maximum capacity;
  8. characteristics of test contents, such as viscosity and relative density for liquids and
    particle size for solids;
  9. test descriptions and results;
  10. signature, with the name and status of the signatory.

This mark on the packaging does not necessarily confirm that the packaging may be used for any substance. For type of packaging and quantity of dangerous goods in packaging one must look into specific entry in chapter 3 and find out what type of packaging is allowed and what is the max allowed mass or quantity per package.