click for Chilworth home click for DEKRA Insight home

laboratory testingp

Accurate classification of dangerous goods for transport

In the interest of public safety, transportation regulations from the UN and the US Department of Transportation (DOT) require the classification of certain types of dangerous goods for transport. They also define appropriate tests and procedures to facilitate this classification. If these chemical substances are not properly identified and packaged for safe transport, they can pose a threat to human lives or the environment. Their accidental release could result in fires and explosions or other catastrophes. Accurate, thorough testing provides protection against the risks to life and property inherent in the transportation of hazardous materials in commerce.

We provide the full suite of tests for the transportation classification of dangerous goods prescribed by UN and DOT regulations. Our GLP and ISO 9001 compliant testing laboratory is equipped to handle powders, liquids, gases and vapours, even those classified or believed to be toxic, highly active or controlled. These facilities, together with our expertise, assist clients in complying with regulatory requirements relating to the transportation of hazardous substances.

Testing for transportation classification - DEKRA
We conduct appropriate tests to classify dangerous goods for transportation purposes.

When you partner with us, you benefit not only from our knowledge, experience and first-rate testing facilities, but also from our commitment to creating a personable, friendly and open working environment. We are keen to share our knowledge and empower our clients.

Comprehensive testing for transport of dangerous goods

Our testing of dangerous goods for transport is based on the UN classification system and includes the full suite of recommended methods and procedures. These include:

  • UN class 1 (Explosives):

    BAM fall hammer, BAM friction and Koenen tube test to measure ignition sensitivity

    Time pressure, UN gap test and fire analysis to measure explosion severity
  • UN class 2 (Aerosols):

    Tests for chemical heat combustion, ignition distance, enclosed space ignition, mist flammability and more
  • UN class 3 (Flammable Liquids):

    Flash point, fire point and sustained combustion testing
  • UN Class 4:

    Division 4.1. (Self-reactive substances and highly-flammable solids):
Adiabatic storage test to determine the SADT, self-accelerating decomposition temperature
Burning rate test to determine the ability of a substance to propagate combustion

    Division 4.2 (Self-heating solids, pyrophoric solids and liquids):
Pyrophoricity test to determine the pyrophoricity of a substance
    Self-heating test to determine the ability of a substance to undergo oxidative self-heating

    Division 4.3 (Substances evolving flammable gases when in contact with water):

    Filter paper and conical tests to determine whether reaction with water produces dangerous gases which may be flammable

All of these tests are performed in accordance with the methods described in the UN and DOT recommendations on the transport of dangerous goods.

Make an appointment with us to find out more about testing for transportation classification!

FAQ about UN transportation classification

We have compiled descriptions of the UN transport classifications and corresponding tests to give you an overview of our services. If you want to learn more about our services and how you can benefit from them, then please contact us.

Why should I use testing and classification services for transport of dangerous goods?

The UN mandates classification of some substances for transport to ensure that the packaging and shipping conditions are safe and pose no threat to human life or the environment. Preventing accidents or disasters is also, of course, in your best interest as your assets and reputation are protected.

What types of substances are classified?

We test for six classification classes: explosives (class 1); aerosols (class 2); flammable liquids (class 3); solid and liquid oxidizing substances (class 5); corrosive substances (class 8); and all three subdivisions of class 4. Class 4 includes self-reactive substances and highly flammable solids; self-heating solids and pyrophoric liquids and solids; and substances evolving flammable gases when in contact with water.

How are explosives (class 1) tested?

A variety of tests are performed on explosives. These include the UN gap test to measure the ability of a substance under confinement to propagate detonation and the Koenen test to determine the sensitivity of a substance to intense heat under high confinement. Moreover, we perform time pressure tests to determine the effects of igniting a substance under confinement. The BAM fallhammer test serves to measure the sensitivity to drop weight impact and the BAM friction test is carried out to measure the sensitivity to friction stimuli. Both tests serve to determine if the substance is too dangerous to transport in the form tested. To measure the stability of substances when subjected to elevated thermal conditions, we conduct the thermal stability test. The small scale burning test determines the response of a substance to fire.

Which tests are carried out on aerosols (class 2)?

Chemical heat combustion, ignition distance, enclosed space ignition, mist flammability and the aerosol foam flammability test among others.

What does class 4 testing involve?

Tests on class 4 substances include, but are not limited to, the burning rate test, the pyrophoric solids test and the dangerous when wet test. The burning rate test involves igniting a 250 mm x 20 mm x 10 mm powder train using a suitable ignition source and measuring the burning rate (time). The pyrophoric solids test involves pouring a powder sample from a height of one meter onto a non-flammable surface and observing whether the sample ignites during its descent or after settling. The dangerous when wet test is comprised of four parts, each of which involves exposing a small amount of solid sample to a limited amount of water. The samples are observed to determine whether gas is evolved and whether such gas is flammable. The volume of gas evolved is measured to determine the gas evolution rate.

Which tests are carried out on class 5 substances?

The solid oxidizing substances test and the oxidizing liquids test. The former involves mixing powder samples with sawdust in various proportions and observing the combustion characteristics when a conical pile of the sample/sawdust mixture is ignited by a hot loop ignition source. The latter involves mixing a 2.5-gram sample of the suspected liquid oxidizer with an equivalent sample of dried fibrous cellulose. The mixture is then loaded into the test cell and ignited using a fuse wire. A pressure transducer fitted to the test cell is used to measure the maximum deflagration pressure and maximum rate of pressure rise. The results for the sample and mixture are then compared to results for testing of mixtures of cellulose and known oxidizers to determine the classification and packing group.

Do you have any other questions you would like to ask us? Contact us.