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UN Recommended Classification Tests

The following tests are UN recommended for use with each test type.  Other tests may exist that satisfy UN criterion for appropriate classification.

Test Series 1

Test Series 1 is comprised of three types of tests and answers the question “Is it an explosive substance?” 

  • Type 1(a): for determining propagation of detonation
  • Type 1(b): for determining the effect of heating under confinement
  • Type 1(c): for determining the effect of ignition under confinement

Test 1(a)– UN Gap Test (zero gap). This test is used to measure the ability of a substance, under confinement in a steel tube, to propagate a detonation by subjecting it to the detonation from a booster charge. 

Test 1(b) – Koenen Test. This test is used to determine the sensitivity of solid and liquid substances to the effect of intense heat under high confinement.

Test 1(c)(i) – Time/Pressure Test.This test is used to determine the effects of igniting the substance under confinement in order to determine if ignition leads to a deflagration with explosive violence at pressures which can be attained with substances in normal commercial packages.


Test Series 2

Test Series 2 comprises of three types of tests and answers the question “Is the substance too insensitive for inclusion in Class 1?”

  • Type 2(a): for determining sensitivity to shock
  • Type 2(b): for determining the effect of heating under confinement
  • Type 2(c): for determining the effect of ignition under confinement

Test 2(a) – UN Gap Test (50mm gap). This test is used to measure the sensitivity of a substance, under confinement in a steel tube, to detonative shock.  

Test 2(b) - Koenen Test. This test is used to determine the sensitivity of solid and liquid substances to the effect of intense heat under high confinement.

Test 2(c)(i) – Time/Pressure Test.  This test is used to determine the effects of igniting the substance under confinement in order to determine if ignition leads to a deflagration with explosive violence at pressures which can be attained with substances in normal commercial packages.


Test Series 3

Test Series 3 comprises of four types of tests and answers the question “Is the substance thermally stable?”

  • Type 3(a): for determining sensitivity to impact
  • Type 3(b): for determining sensitivity to friction (including impact friction)
  • Type 3(c): for determining the thermal stability of a substance
  • Type 3(d): for determining the response of the substance to fire  

Test 3(a)(ii) – BAM Fallhammer.  This test is used to measure the sensitivity of solids and liquids to drop-weight impact and to determine if the substance is too dangerous to transport in the form tested.

Test 3(b)(i) – BAM Friction Apparatus.This test is used to measure the sensitivity of the substance to frictional stimuli and to determine if the substance is too dangerous to transport in the form tested.

Test 3(c) – Thermal Stability Test at 75° C. This test is used to measure the stability of the substance when subjected to elevated thermal conditions to determine if the substance is too dangerous to transport .

Test 3(d) – Small-Scale Burning Test. This test is used to determine the response of a substance to fire.


Test Series 4

Test Series 4 comprises of two types of tests and answers the question “Is the article, packaged article or packaged substance too dangerous for transport?”

  • Type 4(a): a test of thermal stability for articles
  • Type 4(b): a test to determine the danger from dropping

Test 4(a) – Thermal stability test for unpackaged articles and packaged articles. This test is used to evaluate the thermal stability of articles and packaged articles when subjected to elevated thermal conditions to determine whether the unit being tested is too hazardous for transport.

Test 4(b)(i) – The steel tube drop test for liquids. This test is used to determine the explosive behavior of a homogeneous energetic liquid, in a closed steel tube, when it is dropped from various heights onto a steel anvil.

Test 4(b)(ii) – Twelve meter drop test for articles, packaged articles, and packaged substances. This test determines whether a test unit (article, packaged article(s) or packaged substance (other than homogeneous liquids)) can withstand a free-fall impact without producing any significant fire or explosion hazard.  It is not intended as a test to evaluate whether the package will withstand impact.


Test Series 5

Test Series 5 comprises of three types of tests and answers the question “Is it a very insensitive explosive substance with a mass explosion hazard?”

  • Type 5(a): a shock test to determine the sensitivity to intense mechanical stimulus
  • Type 5(b): thermal tests to determine the tendency of transition from deflagration to detonation
  • Type 5(c): a test to determine if a substance, when in large quantities, explodes when subjected to a large fire

Test 5(a) – Cap Sensitivity Test. This shock test is used to determine the sensitivity of a substance to intense mechanical stimulus.

Test 5(b)(ii) – USA DDT Test. This test is used to determine the tendency for the substance to undergo transition from deflagration to detonation.

Test 5(c) – External Fire Test for Division 1.5. This test is used to determine whether a substance, packaged as for transport, can explode if involved in a fire.


Test Series 6

The results from four types of Series 6 Tests are used to determine which division, amongst Divisions 1.1, 1.2, 1.3, and 1.4, corresponds most closely to the behavior of a product if a load is involved in a fire resulting from internal or external sources, or an explosion from internal sources. The results are also necessary to assess whether a product can be assigned to Compatibility Group S of Division 1.4 and whether or not it should be excluded from Class 1.

  • Type 6(a): a test on a single package to determine if there is mass explosion of the contents.
  • Type 6(b): a test on packages of an explosive substance or explosive articles, or non-packaged explosive articles, to determine whether an explosion is propagated from one package to another or from a non-packaged article to another;
  • Type 6(c): a test on packages of an explosive substance or explosive articles, or non-packaged explosive articles, to determine whether there is a mass explosion or a hazard from dangerous projections, radiant heat and/or violent burning or any other dangerous effect when involved in a fire.
  • Type 6(d): a test on an unconfined package of explosive articles to which special provision 347 of Chapter 3.3 of Model Regulations applies, to determine if there are hazardous effects outside the package arising from accidental ignition or initiation of contents.

Test 6(a) – Single Package Test. This is a test on a single package to determine if there is a mass explosion of the contents.

Test 6(b) – Stack Test. This is a test of packages of an explosive substance or explosive articles, or unpackaged explosive articles, to determine whether an explosion is propagated from one package to another or from a unpackaged article to another.

Test 6(c) – External Fire Test. This is a test performed on packages of an explosive substance or explosive articles, or unpackaged explosive articles, to determine whether there is a mass explosion or a hazard from dangerous projections, radiant heat and/or violent burning or any other dangerous effect when involved in a fire.

Test 6(d) – Unconfined Package Test. This is a test on a single package to determine if there are hazardous effects outside the package arising from ignition or initiation of the contents.


Test Series 7

The question “Is it an extremely insensitive explosive article?” is answered by Series 7 Tests and any candidate for Division 1.6 should pass one of each of the ten types of test comprising the series.  The first six types of test are used to establish if a substance is an extremely insensitive detonating substance (EIDS) and the remaining four types are used to determine if an article containing an EIDS(s) may be assigned to Division 1.6

  • Type 7(a): a shock test to determine sensitivity to intense mechanical stimulus
  • Type 7(b): a shock test with a defined booster and confinement to determine sensitivity to shock
  • Type 7(c): a test to determine the sensitivity of the explosive substance to deterioration under the effect of an impact
  • Type 7(d): a test to determine the degree of reaction of the explosive substance to impact or penetration resulting from a given energy source
  • Type 7(e): a test to determine the reaction of the explosive substance to an external fire when the material is confined
  • Type 7(f): a test to determine the reaction of the explosive substance in an environment in which the temperature is gradually increased to 365°C
  • Type 7(g): a test to determine the reaction to an external fire of an article which is in the condition as presented for transport
  • Type 7(h): a test to determine the reaction of an article in an environment in which the temperature is gradually increased to 365°C
  • Type 7(j): a test to determine the reaction of an article to impact or penetration resulting from a given energy source
  • Type 7(k): a test to determine whether a detonation of an article will initiate a detonation in an adjacent, like article

Test 7(a) – EIDS Cap Test. This shock test is designed to determine the sensitivity of an EIDS candidate to intense mechanical stimulus.

Test 7(b) – EIDS Gap Test. This test is used to measure the sensitivity of an EIDS candidate to a specified shock level, i.e. a specified donor charge and gap.

Test 7(c)(ii) – Friability Test. The friability test is used to evaluate the response of an EIDS candidate to the kinetic energy transfer associated with impact and penetration of a given energy source traveling at the specified velocity.

Test 7(d)(i) – EIDS Bullet Impact Test. The bullet impact test is used to evaluate the response of an EIDS candidate to the kinetic energy transfer associated with impact and penetration of a given energy source, i.e. a 12.7 mm projectile, traveling at a specified velocity.

Test 7(e) – EIDS External Fire Test. This test is used to determine the reaction of an EIDS candidate to external fire when it is confined.

Test 7(f) – EIDS Slow Cook-Off Test. This test is used to determine the reaction of an EIDS candidate to a gradually increasing thermal environment and to find the temperature at which reaction occurs.

Test 7(g) – 1.6 Article External Fire Test. This test is used to determine the reaction of a possible Division 1.6 article to external fire as presented for transport.

Test 7(h) – 1.6 Article Slow Cook-Off Test. This test is used to determine the reaction of a candidate Division 1.6 article to a gradually increasing thermal environment and to find the temperature at which reaction occurs.

Test 7(j) – 1.6 Article Bullet impact Test. The bullet impact test is used to evaluate the response of a candidate Division 1.6 article to the kinetic energy transfer associated with the impact and penetration by a given energy source.

Test 7(k) – 1.6 Article Stack Test. This test is used to determine whether a detonation of a candidate Division 1.6 article, as offered for transport, will initiate a detonation in an adjacent, like article.


Test Series 8

The assessment whether a candidate for “ammonium nitrate emulsion or suspension or gel, intermediate for blasting explosives (ANE)” is insensitive enough for inclusion in Division 5.1 is answered by Series 8 Tests and any such candidate for inclusion in Division 5.1 should pass each of the three types of test.

  • Type 8(a): a test to determine the thermal stability
  • Type 8(b): a shock test to determine sensitivity to intense shock
  • Type 8(c): a test to determine the effect of heating under confinement

Test 8(a) – Thermal Stability Test for ANE. This test is used to measure the stability of a candidate for “ammonium nitrate emulsion, suspension or gel, intermediate for blasting explosives” when subjected to elevated thermal conditions to determine if the emulsion is too dangerous for transport.

Test 8(b) – ANE Gap Test. This test is used to measure the sensitivity of a candidate for “ammonium nitrate emulsion, suspension or gel, intermediate for blasting explosives” to a specified shock level, i.e. a specified donor charge and gap.

Test 8(c) – Koenen Test. This test is used to determine the sensitivity of a candidate ammonium nitrate emulsion or suspension or gel, intermediate for blasting explosive, to the effect of intense heat under high confinement.

(Source: United Nations, Recommendations on the Transport of Dangerous Goods)


Point of Contact

Jorge Flores  256.327.4018
HCinfo@apt-research.com