Chemical Engineering July 2018 - 30

Facts At Your Fingertips
UN Codes for Packaging Dangerous Goods
Department Editor: Scott Jenkins
S
hipping and transport of chemicals
require specialized packaging
to mitigate the hazards
that the chemicals may present. Only
packages that are certified to have
met testing standards issued by the
United Nations (UN) Economic and
Social Council (New York, N.Y.; www.
un.org) can be used to transport dangerous
goods, which include most
chemicals. The UN has developed
a code system for classifying packaging
and containers for dangerous
materials. This one-page reference
explains the UN packaging code designations
and provides information on
the categories for each.
UN codes
All packages and containers manufactured
to be " UN-approved " for holiding
potentially dangerous materials
are marked with a code that indicates
the properties of the container and
the physical nature of the product it
contains. The UN packaging codes
begin with a either a capital " UN " or
symbol with a lowercase " u " above a
lowercase " n " inside a circle (Figure
1). The codes consist of a series of
numbers and letters usually stamped
into metal or plastic drums and intermediate
bulk containers (IBCs),
and are printed on boxes and bags.
Packages without the UN certification
mark should not be used for dangerous
goods.
The " UN " at the beginning of the
code states that the package meets
the performance standards set forth
in the UN Recommendations on
the Transport of Dangerous Goods
Model Regulations (Orange book)
[1]. The code's numbers and letters
each provide information about
Container type
Packing group
X = I; Y = II; Z = III
Code
position
Definition
First position
(first number
after " UN " )
TABLE 1. CLASSIFICATIONS FOR TYPES OF CONTAINERS
Third position
Second position
(first letter after
" UN " )
Packaging
identification
code: Identifies
the container
type
Container
types
Code
categories
2 = Wooden
barrel
4 = Box
5 = Bag
6 = Composite
receptable
7 = Pressure
receptacle
B = Aluminum
3 = Jerrican C = Natural wood
D = Plywood
F = Reconstituted
wood
G = Fiberboard
H = Plastic
L = Textile
M = Paper, multiwall
N = Metal other
than steel or Al
P = Glass, porcelain
or stoneware
categories into which the contained
substance falls. Information on what
each component of the code means
is provided in Table 1 and Refs. 2-4.
The code also includes a year and
country, indicating the date and location
of the manufacture of the packaging
container.
Packing groups
Dangerous goods are classified into
one of three UN Packing Groups: I,
II and III, according to the degree of
danger they present. Packing group I
represents high danger, while Group II
is medium danger and Group III presents
low danger.
S if solid; hydrostatic
pressure if liquid
Country of
manufacture
UN 1H2/Y21/S/10/USA
FIGURE 1. Each position in the UN packaging code signifies specific information
Container
UN symbol
material
Additional
characteristic
Max. gross mass
Or specific gravity
30
Year of
manufacture
A key point for shippers with regard
to UN packaging ratings is that
" overpackaging " is appropriate, but
" underpackaging " is
not. That is,
shippers can use containers that are
rated for higher than the properties
of the material within, but not lower.
For example, for materials in packing
Group II, either a X- or Y-rated container
is acceptable, but a Z-rated
container cannot be used. Packages
for Packing Group I will be built to a
higher standard and therefore will be
more expensive than packages of
the same type built for a lower packing
group.
n
References
1. United Nations Economic and Social Council's Committee
of Experts on the Transport of Dangerous Goods,
UN Model Regulations: UN Recommendations on the
Transport of Dangerous Goods, 19th Revision, Parts 4
and 6. United Nations, New York, 2015.
2. New Pig Corp., Cracking the Code: Explaining UN Ratings,
New Pig Blog, www.newpig.com, Post accessed
June 2018.
3. Tasker, Simon, A guide to chemical packaging, posted to
ReAgent Blog (www.reagent.co.uk), February 2012.
4. Label Master, UN Markings Guide, Resources, www.
labelmaster.com; accessed June 2018.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
JULY 2018
1 = Drum
Container material:
Identifies the material
from which the
container is made
Container
materials
A = Steel
Identifies openhead
or closedhead
containers
for drums and
multiwall bags or
multiwall, waterresistant
Drum
type
1: Closed-head
drum
2: Open head
drum
Fourth position
Designates
which packing
group the packaging
can be
used for (from
the hazardous
materials table)
Packing group
X: Packing
groups I, II
and III
Y: II and III
Z: III only
Mass (solids)
Specific gravity
(liquids)
Hydrostatic
pressure
Fifth position
Identifies the
maximum mass
or specific gravity
the container
has been tested
to hold
http://www.un.org http://www.newpig.com http://www.reagent.co.uk http://www.labelmaster.com http://WWW.CHEMENGONLINE.COM
Chemical Engineering July 2018

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