Notification of Ammonium Nitrate Storage (NAMOS)

The Dangerous Substances (Notification and Marking of Sites) Regulations 1990 (NAMOS) aims to ensure that firefighters arriving at an incident are warned of the presence of dangerous substances.

Legislative requirements for fertilizers containing ammonium nitrates

Quantity Stored Local Fire Authority HSE Local Planning Authority
Up to 24 tonnes


Up to 149 tonnes Yes note 1 Yes note 1
> 150 tonnes Yes note 1

>1000 tonnes Yes note 1
Yes note 2
> 1250 tonnes Yes note 1 Yes note 3 Yes note 2
> 10 tonnes (off spec AN)
Yes note 3
  1. The Dangerous Substances(Notification and Marking of Sites) Regulations 1990
  2. The Planning (Hazardous Substances) Regulations, 1992 (as amended)
    a. For any fertilizer containing nitrogen from ammonium nitrate greater than 28% 
  3. Control of Major Accident Hazards (COMAH) Regulations/Seveso Directive For any fertilizer containing nitrogen from ammonium nitrate greater than 28%
    a. For any fertilizer containing nitrogen from ammonium nitrate greater than 28%
    b. For non EU fertilizer, note threshold is 350 tonnes.

Decision making flow chart

The flow diagram below outlines the requirements for notifying storage of:
  1. Dangerous substances (STEP 1)
  2. Relevant ammonium nitrate mixtures (STEP 2) 
NAMOS Flow Chart

Information to be provided if required to notify

If the site is required to notify, the following information is required to be provided to the HSE and local FRS (fire and rescue service) (STEP 1) or local FRS (STEP 2):
  1. The name and address of the person making the notification.
  2. The full postal address of the site.
  3. Simple details of the business at, or planned for, the site.
  4. The planned or estimated date such quantities will be present.
  5. For the presence of over 25 tonnes of dangerous substances (Step 1):
    - Classification of dangerous substances which are liable to be present at the site. 
  6. For the presence of over 150 tonnes of ‘relevant ammonium nitrate mixtures‘ (Step 2):
    - The total quantity of ‘relevant ammonium nitrate mixtures’ at or above 150 tonnes, which is present, or is likely to be present at the site.
Contact details for all UK local FRS can be found at : http://www.fireservice.co.uk/information/ukfrs