Minimum wall thickness:

(a) for a reference steel having a product of Rm  A= 10 000, the wall thickness shall not be less than:


Capacity (C) in litres

Wall thickness (T) in mm

Types 11A, 11B, 11N

Types 21A, 21B, 21N, 31A, 31B, 31N










1000 < C  2000

T = C/2000 + 1.5

T = C/2000 + 1.0

T = C/2000 + 2.0

T = C/2000 + 1.5

2000 < C  3000

T = C/2000 + 1.5

T = C/2000 + 1.0

T = C/1000 + 1.0

T = C/2000 + 1.5

where: A= minimum elongation (as a percentage) of the reference steel to be used on fracture under tensile stress (see;


(b) for metals other than the reference steel described in (a), the minimum wall thickness is given by the following equivalence formula:

where: e1 = required equivalent wall thickness of the metal to be used (in mm);
e0 = required minimum wall thickness for the reference steel (in mm);
Rm1 = guaranteed minimum tensile strength of the metal to be used (in N/mm2)
(see (c));
A1 = minimum elongation (as a percentage) of the metal to be used on fracture
under tensile stress (see
However, in no case shall the wall thickness be less than 1.5 mm.
(c) For purposes of the calculation described in (b), the guaranteed minimum tensile strength of
the metal to be used (Rm1) shall be the minimum value according to national or international
material standards. However, for austenitic steels, the specified value for Rm according to the
material standards may be increased by up to 15% when a greater value is attested in the
material inspection certificate. When no material standard exists for the material in question,
the value of Rm shall be the minimum value attested in the material inspection certificate.


Pressure-relief requirements: IBCs for liquids shall be capable of releasing a sufficient amount of
vapour in the event of fire engulfment to ensure that no rupture of the body will occur. This can be
achieved by conventional pressure relief devices or by other constructional means. The start-todischarge
pressure shall not be higher than 65 kPa (0.65 bar) and no lower than the total gauge
pressure experienced in the IBC (i.e. the vapour pressure of the filling substance plus the partial
pressure of the air or other inert gases, minus 100 kPa (1 bar)) at 55 °C, determined on the basis of a
maximum degree of filling as defined in The required relief devices shall be fitted in the
vapour space.

Specific requirements for flexible IBCs

These requirements apply to flexible IBCs of the following types:
13H1 woven plastics without coating or liner
13H2 woven plastics, coated
13H3 woven plastics with liner
13H4 woven plastics, coated and with liner
13H5 plastics film
13L1 textile without coating or liner
13L2 textile, coated
13L3 textile with liner
13L4 textile, coated and with liner
13M1 paper, multiwall
13M2 paper, multiwall, water resistant
Flexible IBCs are intended for the carriage of solids only.

Bodies shall be manufactured from suitable materials. The strength of the material and the
construction of the flexible IBC shall be appropriate to its capacity and its intended use.

All materials used in the construction of flexible IBCs of types 13M1 and 13M2 shall, after complete
immersion in water for not less than 24 hours, retain at least 85% of the tensile strength as measured
originally on the material conditioned to equilibrium at 67% relative humidity or less.

Seams shall be formed by stitching, heat sealing, gluing or any equivalent method. All stitched seamends
shall be secured.

Flexible IBCs shall provide adequate resistance to ageing and to degradation caused by ultraviolet
radiation or the climatic conditions, or by the substance contained, thereby rendering them appropriate
to their intended use.

For flexible plastics IBCs where protection against ultraviolet radiation is required, it shall be
provided by the addition of carbon black or other suitable pigments or inhibitors. These additives shall
be compatible with the contents and remain effective throughout the life of the body. Where use is
made of carbon black, pigments or inhibitors other than those used in the manufacture of the tested
design type, re-testing may be waived if changes in the carbon black content, the pigment content or
the inhibitor content do not adversely affect the physical properties of the material of construction.

Additives may be incorporated into the material of the body to improve the resistance to ageing or to
serve other purposes, provided that these do not adversely affect the physical or chemical properties of
the material.

No material recovered from used receptacles shall be used in the manufacture of IBC bodies.
Production residues or scrap from the same manufacturing process may, however, be used.
Component parts such as fittings and pallet bases may also be used provided such components have
not in any way been damaged in previous use.

When filled, the ratio of height to width shall be not more than 2:1.

The liner shall be made of a suitable material. The strength of the material used and the construction
of the liner shall be appropriate to the capacity of the IBC and the intended use. Joins and closures
shall be siftproof and capable of withstanding pressures and impacts liable to occur under normal
conditions of handling and carriage.

Specific requirements for rigid plastics IBCs

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