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2.15.2.: Classification criteria
2.15.2.1.
Any organic peroxide shall be considered for classification in this class, unless it contains:
(a)
not more than 1,0 % available oxygen from the organic peroxides when containing not more than 1,0 % hydrogen peroxide; or
(b)
not more than 0,5 % available oxygen from the organic peroxides when containing more than 1,0 % but not more than 7,0 % hydrogen peroxide.
Note
The available oxygen content ( %) of an organic peroxide mixture is given by the formula:
where:
|
ni |
= |
number of peroxygen groups per molecule of organic peroxide i; |
|
ci |
= |
concentration (mass %) of organic peroxide i; |
|
mi |
= |
molecular mass of organic peroxide i. |
2.15.2.2.
Organic peroxides shall be classified in one of the seven categories of ‘Types A to G’ for this class, according to the following principles:
(a)
any organic peroxide which, as packaged, can detonate or deflagrate rapidly shall be defined as organic peroxide TYPE A;
(b)
any organic peroxide possessing explosive properties and which, as packaged, neither detonates nor deflagrates rapidly, but is liable to undergo a thermal explosion in that package shall be defined as organic peroxide TYPE B;
(c)
any organic peroxide possessing explosive properties when the substance or mixture as packaged cannot detonate or deflagrate rapidly or undergo a thermal explosion shall be defined as organic peroxide TYPE C;
(d)
any organic peroxide which in laboratory testing:
(i)
detonates partially, does not deflagrate rapidly and shows no violent effect when heated under confinement; or
(ii)
does not detonate at all, deflagrates slowly and shows no violent effect when heated under confinement; or
(iii)
does not detonate or deflagrate at all and shows a medium effect when heated under confinement;
shall be defined as organic peroxide TYPE D;
(e)
any organic peroxide which, in laboratory testing, neither detonates nor deflagrates at all and shows low or no effect when heated under confinement shall be defined as organic peroxide TYPE E;
(f)
any organic peroxide which, in laboratory testing, neither detonates in the cavitated state nor deflagrates at all and shows only a low or no effect when heated under confinement as well as low or no explosive power shall be defined as organic peroxide TYPE F;
(g)
any organic peroxide which, in laboratory testing, neither detonates in the cavitated state nor deflagrates at all and shows no effect when heated under confinement nor any explosive power, provided that it is thermally stable, i.e. the SADT is 60 °C or higher for a 50 kg package (
8
), and, for liquid mixtures, a diluent having a boiling point of not less than 150 °C is used for desensitisation, shall be defined as organic peroxide TYPE G. If the organic peroxide is not thermally stable or a diluent having a boiling point less than 150 °C is used for desensitisation, the organic peroxide shall be defined as organic peroxide TYPE F.
Where the test is conducted in the package form and the packaging is changed, a further test shall be conducted where it is considered that the change in packaging will affect the outcome of the test.
2.15.2.3.
Criteria for temperature control
The following organic peroxides need to be subjected to temperature control:
(a)
Organic peroxide types B and C with an SADT ≤ 50 C;
(b)
Organic peroxide type D showing a medium effect when heated under confinement (
9
) with an SADT ≤ 50 °C or showing a low or no effect when heated under confinement with an SADT ≤ 45 °C; and
(c)
Organic peroxide types E and F with an SADT ≤ 45 °C.
Test methods for determining the SADT as well as the derivation of control and emergency temperatures are given in the ►M4 UN RTDG ◄ , Manual of Tests and Criteria, Part II, section 28. The test selected shall be conducted in a manner which is representative, both in size and material, of the package.