The following table outlines the sequence of numbers and letters used to describe a UN IBC.
11 — rigid, designed for solids, loaded or unloaded by gravity
21 — rigid, designed for solids, loaded or unloaded under pressure > 10 kPa
13 — flexible, designed for solids, loaded or unloaded by gravity
31 — rigid, designed for liquids, loaded or unloaded by gravity
21 — rigid, designed for solids, loaded or unloaded under pressure > 10 kPa
13 — flexible, designed for solids, loaded or unloaded by gravity
31 — rigid, designed for liquids, loaded or unloaded by gravity
A — steel
B — aluminum
C — natural wood
D — plywood
F — reconstituted wood
G — fibreboard
H — plastic or rubber
L — textile
M — paper
N — metal other than steel or aluminum
B — aluminum
C — natural wood
D — plywood
F — reconstituted wood
G — fibreboard
H — plastic or rubber
L — textile
M — paper
N — metal other than steel or aluminum
1 — rigid inner receptacle (Composite IBC only)
2 — flexible inner receptacle (Composite IBC only)