Notification of dangerous substances and ammonium nitrate on farms

From 6 April 2013, the requirements to notify storage of ammonium nitrate have changed. Under the Dangerous Substances (Notification and Marking of Sites) Regulations 1990 (NAMOS), there are legal requirements relating to notification and marking of sites that store certain amounts of dangerous substances or 'relevant ammonium nitrate mixtures'1

What do I need to do?

If you are storing 25 tonnes or more of dangerous substances you must:

  • Notify your local Fire and Rescue Service
  • Mark the entrance of the site with an appropriate warning sign
  • Notify HSE

If you are storing more than 150 tonnes or more of 'relevant ammonium nitrate mixtures' you must:

  • Notify your local Fire and Rescue Service

HSE guidance INDG467 'Notification and marking of sites. A brief guide to an amendment to the Regulations' provides further details of the changes and includes a flowchart to assist in identifying who should be notified. HS(R)29 'Notification and marking of sites' also provides guidance on notification requirements as well as the requirements for the type and location of warning signs.

What and how do I notify?

Notifications should contain the information set out in the following NAMOS notification form available to assist in recording the necessary information.

Storage of ammonium nitrate

HSE has produced a self-help checklist  to help duty holders to determine if they have taken sufficient measure to ensure the safe storage and handling of the material. More detailed guidance is contained in HSE's free leaflet INDG230 Storing and Handling Ammonium Nitrate .


1 Relevant ammonium nitrate mixtures' is defined as ammonium nitrate and mixtures containing ammonium nitrate, where the nitrogen content exceeds 15.75% of the mixture by weight. Back

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