Intermediate Temporary Storage

Interpretation of the exclusion related to ‘directly related temporary intermediate storage’ in the COMAH Regulations (S.I. 209 of 2015)

Regulation 3(3) of the Chemicals Act (Control of Major Accidents Involving Dangerous Substances) Regulations, S.I. 209 of 2015 sets out a number of exclusions from application of the Regulations. A guide to the COMAH Regulations is available here.


Regulation 3(3(c) excludes: the transport of dangerous substances and directly related intermediate temporary storage by road, rail, internal waterways, sea or air outside establishments defined in Regulation 2(1), including loading and unloading and transport to and from another means of transport at docks, wharves or marshalling yards;


Directly related intermediate temporary storage is interpreted by the Central Competent Authority to include:

  • driver rest breaks and daily/weekly rest periods,
  • time required to transfer a load from one form of transport to another,
  • time required to amalgamate or break down loads of packaged goods or
  • waiting time while transferring from one mode of transport to another.

It does not include:

  • storage of dangerous substances once they have reached a destination point or consignee (however short the duration of their storage)
  • storage of dangerous substances that have been consigned but not yet begun a journey
  • activity to decant /dilute or otherwise alter the dangerous substances from the form in which they have been transported.

Where the quantity of dangerous substances stored at a location would exceed the COMAH threshold:

  • for a continuous (or near continuous) period of 96 hours (4 consecutive days)  or
  • for a total of 480 hours (20 days) in any 12- month period

the COMAH Regulations will be deemed to apply and the operator of the location (that is, the entity with economic control) will be required to make a formal notification under the COMAH Regulations.

This may trigger consequent land-use planning, emergency response planning and public information requirements arising from the Regulations.