The chemically unstable substances of Class 5.1 shall not be accepted for carriage unless the necessary steps have been taken to prevent their dangerous decomposition or polymerization during carriage. To this end it shall in particular be ensured that receptacles and tanks do not contain any material liable to promote these reactions.
The following substances and mixtures shall not be accepted for carriage:
- oxidizing solids, self-heating, assigned to UN No. 3100, oxidizing solids, water-reactive, assigned to UN No. 3121 and oxidizing solids, flammable, assigned to UN No. 3137, unless they meet the requirements for Class 1 (see also 126.96.36.199);
- hydrogen peroxide, not stabilized or hydrogen peroxide, aqueous solutions, not stabilized containing more than 60% hydrogen peroxide;
- tetranitromethane not free from combustible impurities;
- perchloric acid solutions containing more than 72% (mass) acid, or mixtures of perchloric acid with any liquid other than water;
- chloric acid solution containing more than 10% chloric acid or mixtures of chloric acid with any liquid other than water;
- halogenated fluor compounds other than UN Nos. 1745 BROMINE PENTAFLUORIDE; 1746 BROMINE TRIFLUORIDE and 2495 IODINE PENTAFLUORIDE of Class 5.1 as well as UN Nos. 1749 CHLORINE TRIFLUORIDE and 2548 CHLORINE PENTAFLUORIDE of Class 2;
- ammonium chlorate and its aqueous solutions and mixtures of a chlorate with an ammonium salt;
- ammonium chlorite and its aqueous solutions and mixtures of a chlorite with an ammonium salt;
- mixtures of a hypochlorite with an ammonium salt;
- ammonium bromate and its aqueous solutions and mixtures of a bromate with an ammonium salt;
- ammonium permanganate and its aqueous solutions and mixtures of a permanganate with an ammonium salt;
- ammonium nitrate containing more than 0.2% combustible substances (including any organic substance calculated as carbon) unless it is a constituent of a substance or article of Class 1;
-ammonium nitrate based fertilizers with compositions that lead to exit boxes 4, 6, 8, 15, 31, or33 of the flowchart of paragraph 39.5.1 of the Manual of Tests and Criteria, Part III, Section39, unless they have been assigned a suitable UN number in Class 1;
-ammonium nitrate based fertilizers with compositions that lead to exit boxes 20, 23 or 39 of theflowchart of paragraph 39.5.1 of the Manual of Tests and Criteria,Part III, Section 39, unlessthey have been assigned a suitable UN number in Class 1 or, provided that the suitability forcarriage has been demonstrated and that this has been approved by the competent authority, inClass 5.1 other than UN No. 2067;
NOTE:The term “competent authority” means the competent authority of the country oforigin. If the country of origin is not a Contracting Party to ADR, the classification andconditions of carriage shall be recognized by the competent authority of the firstcountryContracting Party to ADR reached by the consignment.
-ammonium nitrite and its aqueous solutions and mixtures of an inorganic nitrite with anammonium salt;
-mixtures of potassium nitrate, sodium nitrite and an ammonium salt.
The heading of Class 5.2 covers organic peroxides and formulations of organic peroxides.
The substances of Class 5.2 are subdivided as follows:
P1 Organic peroxides, not requiring temperature control;
P2 Organic peroxides, requiring temperature control.
Organic peroxidesare organic substances which contain the bivalent -O-O- structure and may be considered derivatives of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals.
Organic peroxides are liable to exothermic decomposition at normal or elevated temperatures. The decomposition can be initiated by heat, contact with impurities (e.g. acids, heavy-metal compounds, amines), friction or impact. The rate of decomposition increases with temperature and varies with the organic peroxide formulation. Decomposition may resultin the evolution of harmful, or flammable, gases or vapours. For certain organic peroxides the temperature shall be controlled during carriage. Some organic peroxides may decompose explosively, particularly if confined. This characteristic may be modifiedby the addition of diluents or by the use of appropriate packagings. Many organic peroxides burn vigorously. Contact of organic peroxides with the eyes is to be avoided. Some organic peroxides will cause serious injury to the cornea, even after brief contact, or will be corrosive to the skin.
NOTE:Test methods for determining the flammability of organic peroxides are set out in the Manual of Tests and Criteria, Part III, sub-section 32.4. Because organic peroxides may react vigorously when heated, it is recommended to determine their flash-point using small sample sizes such as described in ISO 3679:1983.
Any organic peroxide shall be considered for classification in Class 5.2 unless the organic peroxide formulation contains:
(a) Not more than 1.0% available oxygen from the organic peroxides when containing not morethan 1.0% hydrogen peroxide;
(b) Not more than 0.5% available oxygen from the organic peroxides when containing more than1.0% but not more than 7.0% hydrogen peroxide.
NOTE:The available oxygen content (%) of an organic peroxide formulation is given by the formula
16 × Σ(ni× ci/mi)
ni = number of peroxygen groups per molecule of organic peroxide i;
ci=concentration (mass %) of organic peroxide i; and
mi=molecular mass of organic peroxide i.
Organic peroxides are classified into seven types according to the degree of danger they present. The types of organic peroxide range from typeA, which is not accepted for carriage in the packaging in which it is tested, to typeG, which is not subject to the provisions of Class5.2. The classification of types B to F is directly related to the maximum quantity allowed in one package. The principles to be applied to the classification of substances not listed in 188.8.131.52 are set out in the Manual of Tests and Criteria, Part II.
Organic peroxides which have already been classified and are already permitted for carriage in packagings are listed in 184.108.40.206, those already permitted for carriage in IBCs are listed in220.127.116.11, packing instruction IBC520 and those already permitted for carriage in tanks in accordance with Chapters 4.2 and 4.3 are listed in18.104.22.168, portable tank instruction T23. Each permitted substance listed is assigned to a generic entry of Table A of Chapter 3.2 (UN Nos. 3101 to 3120) and appropriate subsidiary hazardsand remarks providing relevant transport information are given.
These generic entries specify:
- the type (B to F) of organic peroxide (see 22.214.171.124.6 above);
- physical state (liquid/solid); and
- temperature control (when required), see 126.96.36.199.15 and 188.8.131.52.16.
Mixtures of these formulations may be classified as the same type of organic peroxide as that of the most dangerous component and be carried under the conditions of carriage given for this type. However, as two stable components can form a thermally less stable mixture, the self-accelerating
decomposition temperature (SADT) of the mixture shall be determined and, if necessary, the control and emergency temperatures derived from the SADT in accordance with 184.108.40.206.6.
Classification of organic peroxides not listed in 220.127.116.11, 18.104.22.168 packing instruction IBC520 or 22.214.171.124, portable tank instruction T23, and assignment to a collective entry shall be made by the competent authority of the country of origin. The statement of approval shall contain the classification and the relevant conditions of carriage. If the country of origin is not a Contracting Party to ADR, the classification and conditions of carriage shall be recognized by the competent authority of the first country Contracting Party to ADR reached by the consignment.
Samples of organic peroxides or formulations of organic peroxides not listed in 126.96.36.199, for which a complete set of test results is not available and which are to be carried for further testing or evaluation, shall be assigned to one of the appropriate entries for organic peroxides type C provided the following conditions are met:
- the available data indicate that the sample would be no more dangerous than organic peroxides type B;
- the sample is packaged in accordance with packing method OP2 and the quantity per transport unit is limited to 10 kg;
- the available data indicate that the control temperature, if any, is sufficiently low to prevent any dangerous decomposition and sufficiently high to prevent any dangerous phase separation.
In order to ensure safety during carriage, organic peroxides are in many cases desensitized by organic liquids or solids, inorganic solids or water. Where a percentage of a substance is stipulated, this refers to the percentage by mass, rounded to the nearest whole number. In general, desensitization shall be such that, in case of spillage, the organic peroxide will not concentrate to a dangerous extent.