These details are what UKRA currently understands to be correct however we have not had these checked by a lawyer or the HSE.
After years of discussions between UKRA and the HSE, most rocketeers now require very little paperwork. All model, mid and even some smaller high powered engines can now be purchased without an Explosives Licence, just an RCA is required for transportation purposes.
Rocketeers who wish to purchase larger motors (from about mid K) or store a large amount of motors or black powder, or those not on the list of exempted motors will still require paperwork.
The law in summary states that any person over the age of 18 is allowed to purchase and store a combined total of 5kg of explosives if that explosive is contained within a list of exemptions and each motor being less than 1Kg net propellant (see the HSE pages here). Please note that with regard rocket motors the weight is the net propellant weight and not the gross weight which will include packaging. If you do not know the net propellant weight, then the law states that you must assume one quarter of the product weight is propellant. Details of the exemption may be found in Schedule 2 of the Explosives Regulations 2014 paragraph 10. The following UN numbers are listed under the exemption - 0186, 0272, 0349, 0351 and 0471.
If you or the motors do not meet the criteria above then you will need to get an Explosives Licence and an RCA. To apply for a Storage licence you will need to fill in an ER1 form, to apply for a Acquire and Keep licence you will need to fill in an ER4 form. Both of these application processes are likely to incur fees and you should contact your local police firearms division. HSE do hold a master list here but it seems to get out of date quickly. We have found more success contacting your local police force directly, most police forces publish the contact details for their FEO (Firearms Enquiry Officers) on their websites.
An RCA is also required for those who will be transporting motors covered by the exemptions (i.e. between your home and the launches). Explosives certificates issues by Police forces after 2012 should include the RCA document (see "How do I apply for, or renew an RCA document?" here). For those without explosives certificates the HSE has prepared a template letter in Word format for Rocketeers to apply to move their model rocket motors. The completed letter can be sent by email to firstname.lastname@example.org or by post to the address on the letter.
The letter includes all the information for the exempted motors and also includes UN numbers for other common items that are exempt from the need for an explosives license e.g. quickmatch, igniters, Estes motors and PIC.
The full details of the requirements can be found in the S.I. 1638 - Explosives Regulations 2014.
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