Dangerous Goods by Road
Certain substances are chemically unstable. They are accepted for carriage only when the necessary
steps have been taken to prevent their dangerous decomposition, transformation or polymerization
during carriage. To this end, care shall in particular be taken to ensure that shells do not contain any
substances liable to promote these reactions.
The temperature of the outer surface of the shell excluding openings and their closures or of the
thermal insulation shall not exceed 70 °C during carriage. When necessary, the shell shall be
thermally insulated.
Empty portable tanks not cleaned and not gas-free shall comply with the same provisions as portable
tanks filled with the previous substance.
Substances shall not be carried in the same or in adjoining compartments of shells when they may
react dangerously with each other (see definition for "dangerous reaction" in 1.2.1).
The design approval certificate, the test report and the certificate showing the results of the initial
inspection and test for each portable tank issued by the competent authority or its authorized body
shall be retained by the authority or body and the owner. Owners shall be able to provide this
documentation upon the request of any competent authority.
Unless the name of the substance(s) being carried appears on the metal plate described in 6.7.2.20.2 a
copy of the certificate specified in 6.7.2.18.1 shall be made available upon the request of a competent
authority or its authorized body and readily provided by the consignor, consignee or agent, as
appropriate.
Degree of filling
Prior to filling, the consignor shall ensure that the appropriate portable tank is used and that the
portable tank is not filled with substances which in contact with the materials of the shell, gaskets,
service equipment and any protective linings, are likely to react dangerously with them to form
dangerous products or appreciably weaken these materials. The consignor may need to consult the
manufacturer of the substance in conjunction with the competent authority for guidance on the
compatibility of the substance with the portable tank materials.
Portable tanks shall not be filled above the extent provided in 4.2.1.9.2 to 4.2.1.9.6. The applicability
of 4.2.1.9.2, 4.2.1.9.3 or 4.2.1.9.5.1 to individual substances is specified in the applicable portable
tank instruction or special provisions in 4.2.5.2.6 or 4.2.5.3 and Column (10) or (11) of Table A of
Chapter 3.2.
The maximum degree of filling (in %) for general use is determined by the formula:
| Degree of filling |
 |
The maximum degree of filling (in %) for liquids of Class 6.1 and Class 8, in packing groups I and II,
and liquids with an absolute vapour pressure of more than 175 kPa (1.75 bar) at 65 °C, is determined
by the formula:
In these formulae, α is the mean coefficient of cubical expansion of the liquid between the mean
temperature of the liquid during filling (tf) and the maximum mean bulk temperature during carriage
(tr) (both in °C). For liquids carried under ambient conditions α could be calculated by the formula:
in which d15 and d50 are the densities of the liquid at 15 °C and 50 °C, respectively.
The maximum mean bulk temperature (tr) shall be taken as 50 °C except that, for journeys under
temperate or extreme climatic conditions, the competent authorities concerned may agree to a lower or
require a higher temperature, as appropriate.
The provisions of 4.2.1.9.2 to 4.2.1.9.4.1 do not apply to portable tanks which contain substances
maintained at a temperature above 50 °C during carriage (e.g. by means of a heating device). For
portable tanks equipped with a heating device, a temperature regulator shall be used to ensure the
maximum degree of filling is not more than 95% full at any time during carriage.
The maximum degree of filling (in %) for solids carried above their melting point and for elevated
temperature liquids shall be determined by the following formula:
in which df and dr are the densities of the liquid at the mean temperature of the liquid during filling
and the maximum mean bulk temperature during carriage respectively.