6 replies to this topic

[Arthur Brown]

Looking for a correct and referenced explanation of firework category (ie cat 1 - 4) and Hazard Class (ie 1.1 - 1.6 and the letters)

Can anyone produce a good summary of the legislation please. Or produce good links!

Edited by Arthur Brown, 19 November 2007 - 10:03 PM.

[Mortartube]

Hopefully this is what you are looking for. It also applies to explosive articles not just substances as listed here.

http://www.ribbands....ages/hazcat.htm

[Arthur Brown]

Ok I have the UN Hazard class but how does it correlate - does it even- with firework categories 1 - 4.

I can buy a retail available candle that is cat 2 or cat3 yet as it has a projectile component it could be class 1.2 and need coer approval to handle it.

Is there a correlation between class and category?

[Richard H]

Generally the majority of categories 1-3 (indoor/garden/display) fireworks fall into 1.4G (HSE -> HT4). The exception being fireworks which, according to the new default classifications for fireworks, fall into 1.3G (HSE -> HT3) (for example the large shell burst rockets).

It is obviously important for the majority of consumer fireworks to be 1.4G because it makes their transport and of course storage by seasonal retailers relatively simple.

Category 4 fireworks range from 1.1G to 1.4G. It is safe to say you will not find any consumer firework that poses a greater hazard division than 1.3G.

For the full text of the UN Model Regulations, visit: http://www.unece.org.../14files_e.html

The observant reader will note our soon to be vastly expanded website helpfully links to this document already

[BrightStar]

After the Plymouth fireworks conference, I mentioned to some of the organisers that while recently Cat 4 trained, I occasionally dabbled in amateur firework construction. This wasn't particularly well received. One comment that struck me was 'You realise that anything you do yourself is 1.1G?'

Is this true? I would have rated my 3" and 4" star shells as 1.3G at most...

Edited by BrightStar, 20 November 2007 - 07:46 PM.

[Arthur Brown]

My personal suspicion is that all devices will be assumed worst case (1.1) until proven otherwise. so a prototype or one-off will be 1.1 til a test batch has been independently assessed as a lower classification.

The reason for the expense of tiny little effects called "stage pyro" is the cost of certification and type approval when possibly 1000 devices will have to be made for testing before anything can have the Competent Authority Document to allow it to be classified as stage pyro (and even that is going T1 and T2 -more hazardous effects needing more certificates for the firer.

[Richard H]

See this document: https://www.hse.gov....losive/lp83.pdf

Read the back section for the default classifications assumed by HSE in the absence of explicit test data. Shells up to 6" are generally 1.3G, with exceptions that will suggest themselves to all experienced members here without further comment.