Dangerous Goods by Road
All portable tanks intended for the carriage of flammable liquids shall be closed and be fitted with
relief devices in accordance with 6.7.2.8 to 6.7.2.15.
For portable tanks intended for use only on land, open venting systems may be used if allowed
according to Chapter 4.3.
Additional provisions applicable to the carriage of Classes 4.1, 4.2 or 4.3 substances (other than Class 4.1 self-reactive substances) in portable tanks
(Reserved)
NOTE: For Class 4.1 self-reactive substances, see 4.2.1.13.1.
Additional provisions applicable to the carriage of Class 5.1 substances in portable tanks
(Reserved)
Additional provisions applicable to the carriage of Class 5.2 substances and Class 4.1 self-reactive substances in portable tanks
Each substance shall have been tested and a report submitted to the competent authority of the country
of origin for approval. Notification thereof shall be sent to the competent authority of the country of
destination. The notification shall contain relevant transport information and the report with test
results. The tests undertaken shall include those necessary:
(a) To prove the compatibility of all materials normally in contact with the substance during
carriage;
(b) To provide data for the design of the pressure and emergency relief devices taking into account
the design characteristics of the portable tank.
Any additional provision necessary for safe carriage of the substance shall be clearly described in the
report.
The following provisions apply to portable tanks intended for the carriage of Type F organic
peroxides or Type F self-reactive substances with a Self-Accelerating Decomposition Temperature
(SADT) of 55 °C or more. In case of conflict these provisions prevail over those specified in Section
6.7.2. Emergencies to be taken into account are self-accelerating decomposition of the substance and
fire-engulfment as described in 4.2.1.13.8.
The additional provisions for carriage of organic peroxides or self-reactive substances with a SADT
less than 55 °C in portable tanks shall be specified by the competent authority of the country of origin.
Notification thereof shall be sent to the competent authority of the country of destination.
The portable tank shall be designed for a test pressure of at least 0.4 MPa (4 bar).
Portable tanks shall be fitted with temperature sensing devices.
Portable tanks shall be fitted with pressure-relief devices and emergency-relief devices. Vacuum-relief
devices may also be used. Pressure-relief devices shall operate at pressures determined according to
both the properties of the substance and the construction characteristics of the portable tank. Fusible
elements are not allowed in the shell.
The pressure-relief devices shall consist of spring-loaded valves fitted to prevent significant build-up
within the portable tank of the decomposition products and vapours released at a temperature of
50 °C. The capacity and start-to-discharge pressure of the relief valves shall be based on the results of
the tests specified in 4.2.1.13.1. The start-to-discharge pressure shall, however, in no case be such that
liquid would escape from the valve(s) if the portable tank were overturned.
The emergency-relief devices may be of the spring-loaded or frangible types, or a combination of the
two, designed to vent all the decomposition products and vapours evolved during a period of not less
than one hour of complete fire-engulfment as calculated by the following formula:
The start-to-discharge pressure of the emergency-relief device(s) shall be higher than that specified
in 4.2.1.13.7 and based on the results of the tests referred to in 4.2.1.13.1. The emergency-relief
devices shall be dimensioned in such a way that the maximum pressure in the portable tank never
exceeds the test pressure of the tank.
NOTE: An example of a method to determine the size of emergency-relief devices is given in
Appendix 5 of the "Manual of Tests and Criteria".
For insulated portable tanks the capacity and setting of emergency-relief device(s) shall be determined
assuming a loss of insulation from 1% of the surface area.
Vacuum-relief devices and spring-loaded valves shall be provided with flame arresters. Due attention
shall be paid to the reduction of the relief capacity caused by the flame arrester.