Segregation rules help minimise the risk of incompatible substances reacting dangerously if they were to come into contact with each other. Such contact might be caused by a leak, spill or vehicle accident. Segregation is particularly important to prevent foodstuffs from being contaminated.
The ADG Code has considerable information covering segregation rules, the types of - and design tests for - segregation devices, and how to use such devices.
This overview indicates where to find relevant information in the code.
When do segregation rules apply?
Segregation rules generally apply whenever a placard load of dangerous goods is transported.
The following also applies:
- no quantity of dangerous goods of:
may be transported with food or food packaging.
- division 2.3 (toxic gas)
- class 6 (infectious substance)
- class 8 (corrosive), or
- with a subsidiary risk of 6 or 8
- incompatible substances may not be transported together in the same overpack (such as a shrink-wrapped pallet).
However, there are some exceptions to these segregation rules. They do not apply to:
- food or packaging carried in the cabin for the driver’s personal use
- class 8 food ingredients intended for use in food manufacturing
- dangerous goods in an overpack or on a vehicle when all of the dangerous goods are 'limited quantities' items.
Consider both the primary hazard and the subsidiary risk (if any) of a substance when assessing whether it is compatible with any other substance.
What segregation rules apply?
Tables 9.1 and 9.2 in the ADG Code set out which classes and divisions, or which specific substances, are incompatible.
Several commercially available segregation charts set out this information using tables and symbols.
How to achieve segregation
There are many ways to segregate incompatible substances to allow them to be transported on the same vehicle.
For combination vehicles (B-Double or road trains), segregation can be achieved in most cases by loading goods onto separate trailers. However, certain goods must never be transported together on any vehicle. These are listed in the ADG Code (table 9.3).
Otherwise, a segregation device (complying with ADG Code 6.11) can be used to isolate incompatible goods.
Segregate goods by any of these means:
- an overpacking drum segregation device (see ADG Code 6.11.2)
- a type I segregation device; no approval is required (see ADG Code 6.11.3)
- a type II segregation device; a specific design approval is required (see ADG Code 6.11.4), or
- some other method of segregation, such as a fixed locker attached to a vehicle which has been given specific approval under the Regulation.
Use of segregation devices
Section 4.4.5 of the ADG Code sets out certain requirements for using a segregation device.
The only dangerous goods packages or unpackaged dangerous goods articles that can be stowed in the device are:
- packages and articles must be stowed so they remain in position during transport
- the segregation device must be restrained so it remains in position
- all other goods must be stowed so they will not be affected by any leak from the device
- dangerous goods and incompatible goods must not be stowed above each other
- for road and rail transport, an overpacking drum must be labelled as for an overpack - i.e. marked with the proper shipping name, the United Nations number (UN number) and the dangerous goods label for each item contained in the drum (see ADG Coce 126.96.36.199)
- type I and type II devices must be labelled on each vertical side that may be exposed during loading or transport, with labels at least 250 mm square
- other methods of segregation must be marked according to the approval given.
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Page last updated: 10 May 2013