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Recommendations on the
Tests and Criteria
Fifth revised edition
Recommendations on the
Tests and Criteria
Fifth revised edition
UNITED NATIONSNew York and Geneva, 2013 NOTE The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries.
ST/SG/AC.10/11/Rev.5/Amend.2 Copyright © United Nations, 2013 All rights reserved.
No part of this publication may, for sales purposes, be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, magnetic tape, mechanical, photocopying or otherwise, without prior permission in writing from the United Nations.
UNITED NATIONS PUBLICATIONSales No. E.13.VIII.3 ISBN 978-92-1-139148-0 e-ISBN 978-92-1-056220-1
FOREWORDThe Manual of Tests and Criteria contains criteria, test methods and procedures to be used for classification of dangerous goods according to the provisions of Parts 2 and 3 of the United Nations Recommendations on the Transport of Dangerous Goods, Model Regulations1, as well as of chemicals presenting physical hazards according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)2.
As a consequence, it supplements also national or international regulations which are derived from the United Nations Recommendations on the Transport of Dangerous Goods or the GHS.
Originally developed by the Economic and Social Council’s Committee of Experts on the Transport of Dangerous Goods which adopted a first version in 1984, it has been regularly updated and amended every two years. Presently, the updating is done under the auspices of the Committee of Experts on the Transport of Dangerous Goods and on the Globally Harmonized System of Classification and Labelling of Chemicals, which replaces the original committee since 2001.
The fifth revised edition, published in 2009, includes all the amendments to the fourth revised edition adopted by the Committee at its second and third sessions in 2004 and 2006 (published under the symbols ST/SG/AC.10/11/Rev.4/Amend.1 and ST/SG/AC.10/11/Rev.4/Amend.2) and those adopted at its fourth session in 2008 (ST/SG/AC.10/36/Add.2 and -/Corr.1).
Amendment 1 to the fifth revised edition includes all the amendments adopted by the Committee at its fifth session (10 December 2010)3 and the corrections adopted by the Sub-Committee of Experts on the Transport of Dangerous at its thirty-ninth session (20-24 June 2011)4.
At its sixth session (14 December 2012), the Committee adopted a new set of amendments to the fifth revised edition5 which are reproduced in this Amendment 2.
AMENDMENTS TO THE GENERAL INTRODUCTIONSection 1
AMENDMENTS TO PART I OF THE MANUALSection 17
AMENDMENTS TO PART II OF THE MANUALSection 20
AMENDMENTS TO PART III OF THE MANUALTable of contents
PART II OF THE MANUALSECTION 20 In the first sentence, delete “and exothermic decomposition energy”.
22.214.171.124 Add the following new second sentence: “Exothermic decomposition energy may be estimated using a suitable calorimetric technique such as differential scanning calorimetry.”
Table of contents In Note 2, at the beginning, insert “Unless otherwise specified,”.
At the end of Section 34 insert: “34.4.3 Test O.3 Gravimetric test for oxidizing solids (UN)”.
SECTION 32 126.96.36.199 to 188.8.131.52 Delete.
SECTION 34 In the second sentence, replace “test method is given” by “test methods are given”.
34.3.1 34.4.3 Insert the following new sub-section 34.4.3:
“34.4.3 Test O.3: Gravimetric test for oxidizing solids 184.108.40.206 Introduction This test method is designed to measure the potential for a solid substance to increase the burning rate or burning intensity of a combustible substance when the two are thoroughly mixed. Tests are conducted on the test substance to be evaluated mixed with dry fibrous cellulose in mixing ratios of 1:1 and 4:1, by mass. The burning rates of these mixtures are compared to the reference mixture of calcium peroxide and cellulose in a mixing ratio of 1:2, by mass. The mass loss of the mixtures during combustion is determined using a balance connected to a suitable data recording system, and is recorded as a function of time. If the burning rate (g/s) is equal to or greater than the burning rate of the reference mixture for Packing Group III, it is then compared to the burning rate of the reference mixtures for Packing Group I or II (see table in 220.127.116.11).
The United Nations Globally Harmonized System of classification and labeling of chemicals (GHS), also refers to this test for classification within the hazard class Oxidizing Solids. For the ranking according to oxidizing power, the GHS uses three categories which correspond exactly to the Packing Groups used within the transport of dangerous goods regime. The GHS categories 1, 2 and 3 thus correspond directly to Packing Groups I, II and III, respectively.
It is useful to have preliminary information on any potentially explosive properties of the substance before performing the test, screening procedures can be found in Appendix 6. This test is not applicable for substances which are explosive or flammable and also not for organic peroxides.
18.104.22.168.1 Technically pure, finely powdered calcium peroxide with a concentration of 75 % ± 0.5 % is required as the reference oxidizer. The concentration of impurities such as chlorides or compounds which generate water during combustion should be low, as they may impact on the burning behavior of the reference piles. Calcium peroxide meeting the specification below can be used without further pretreatment.4
22.214.171.124.2 Dried fibrous cellulose with a fibre length between 50 µm and 250 µm and a mean diameter of 25 µm is used as the combustible material. It is dried to constant mass (for a minimum of 4 hours), in a layer no more than 25 mm thick, at 105 °C and kept in a desiccator (with desiccant) until cool and required for use. The water content should be less than 0.5 % by dry mass. If necessary, the drying time should be prolonged to achieve this. The bulk density of the cellulose used for the test should be such (sufficiently high) that the test mixture for Packing Group III (30.0 g ± 0.1 g) can be completely accommodated in the conical funnel.
126.96.36.199.3 The test-substance, in the form in which it will be presented, should be inspected for any particles less than 500 µm in diameter. If that powder constitutes more than 10 % (by mass) of the total, or if the substance is friable, then the whole of the test sample should be ground to a powder of less than 500 µm before testing, to allow for a reduction in particle size during handling and transport. Because the particle size influences the oxidizing properties of a substance, a coarse oxidizer may be classified as Packing Group III, while a finer grade of the same material may show a faster burning rate and may result in different GHS classifications and assigned transport Packing Groups for different forms of the same material.
188.8.131.52.1 An appropriate balance is required, with a suitable range, accuracy and data transfer capability, equipped with an interface (e.g. USB or RS232) to allow data acquisition. The required data (time, mass) are recorded, preferably with a frequency of at least 5 data per second. Any suitable software capable of recording the output of the balance may be used. It is recommended to check the time frequency of the software and the monitoring of time by a stopwatch maybe useful.
184.108.40.206.2 An ignition source is required, comprising an inert metal wire connected to an electrical power source capable of maintaining the power dissipation specified below. The electrical resistance
depends on the wire material. It is recommended to use Nickel/Chromium or AluChrom wire as follows:
The wire should be shaped as shown in figure 220.127.116.11. It is very important that the power connection to the heating wire is flexible enough to avoid any influence on the proper operation of the balance.
18.104.22.168.3 A 60° funnel, with an internal diameter of 70 mm and sealed at the narrow end, is required to form the mixtures into a truncated conical pile with a base diameter of 70 mm on a cool, impervious, low heat conducting plate.
22.214.171.124.4 An insulating test plate is needed to avoid loss of energy by thermal conduction. A 150 mm by 150 mm test plate with a thickness of at least 6 mm and a thermal conductivity at 0 °C of 0.23 W*m-1*K-1 or less is suitable. Other plates with a similar conductivity may be used. In order to increase the lifetime of the test plate, it may be covered with a thin ceramic sheet with the same low thermal conductivity.
126.96.36.199.5 A fume cupboard or other suitably ventilated area is required but the air stream velocity should be 0.5 m/s or less. The fume extraction system should be capable of capturing all toxic fumes.
Technical information about a suitable design and video training are obtainable from the national contact for test details in Germany (Appendix 4)
-5To construct the support for the burning trial on the balance a base plate of solid material (steel or other suitable material), a positioning plate of fire resistant material (the same material as test-plate is recommended) and guide bars are required.
188.8.131.52.7 The air stream of the ventilation must be prevented from affecting the balance and thereby altering the test result. A windshield protecting the complete test equipment against draughts from the ventilation or environment is the preferred means.
184.108.40.206.8 It is mandatory that the burning conical pile is always placed at the centre of the balance. It is also important to protect the balance from heat and burning particles during the test. To achieve this, the
following general configuration is recommended (the letters in brackets refer to figure 220.127.116.11):
-6g ± 0.1 g of each of the reference mixtures and 30.0 g ± 0.1 g of both mixtures of the test substance are prepared. Each mixture should be mixed mechanically as thoroughly as possible for at least 1 minute, but without excessive stress. Each mixture should be prepared individually, used as soon as possible, and not taken from a batch.
18.104.22.168.2 Using the conical funnel, the mixture should be formed into a truncated conical pile with a base diameter of 70 mm. Form the pile by tapping the funnel slightly after filling; cover the funnel with the test plate -including the sheet (if any)- and invert both. Tap slightly on the funnel before removing. The pile should now cover the looped ignition wire resting on test plate. The test should be performed at atmospheric pressure with an ambient temperature of 20 °C ± 5 °C and a relative humidity below 60 %, to reduce absorption of moisture by the cellulose during handling.
22.214.171.124.3 The balance, placed in the ventilated area as mentioned above is set to zero. Power is applied to the ignition wire and is maintained for the duration of the test, or for three minutes if the mixture does not ignite and burn. Data collection should start a few seconds before the power supply is switched on, and should proceed until the reaction ends or the mass loss over 1 minute is less than 1 g. If the heating wire breaks, the test should be repeated to ensure that early breakage of the wire does not influence the test result.
126.96.36.199 Test criteria and method of assessing results 188.8.131.52.1 The results are assessed on the basis of:
In the main combustion period the mass loss per unit time is quite constant. For this reason a linear regression (based on the least square approach) can be used to check the quality of the data collected.
184.108.40.206.3 The burning rate (BR) depends on the burning intensity and the amount of cellulose in the mixture. It is therefore defined as the quotient of 60 % of the total amount of cellulose in the conical pile and the main combustion time t20-80. The time t20-80 is the time between 20 % and 80 % of the total mass loss. The total mass loss is the difference in mass before ignition and at the end of the main reaction, defined as a rate of mass loss rate of less than 1 g per minute.
The profile of each burning test has to be examined by plotting the mass loss as a function of time. The graph can also be used for decision making and should be used in case of doubt. The coefficient of correlation (R²) of the mass curve of each burning test should be at least 0.95 between 20 % to 80% mass
For substances having other risks, e.g. toxicity or corrosivity, section 2.0.3 of the Model Regulations applies.
In GHS terminology, the test criteria for determining the classification due to the oxidizing
properties of a solid substance are analogous to those used in transport: