No regulations, but as above they can be judged as an ignition risk & it's more realistic to tackle the fire as it starts in the FLT than when it's spread to the packaging.
In the good old days you would bracket a 1.5kg BCF to the FLT but these days you have a variety of choices:
- 1 kilo ABC Powder: Compact, all purpose, fast, cheap BUT messy,doesn't penetrate well, doesn't cool
- 1* or 2 litre AFFF:Still compact, very good at cooling & preventing reignition, relatively cheap BUT, not advisable above 12/24V, doesn't penetrate too well
- 1* or 2 kilo CO2: Non messy,covers the risks it's there for, great penetration BUT doesn't cool, poor outside or in draughts, bigger, need special separate transport bracket, horn at risk of damage rendering it useless and most expensive.
* I know the EN3 purists will leap up & down at these, but 1L AFFF & 1kg CO2 are still readily available new.
I've seen all different types in use, it's down to you to weigh up the pros & cons as to which is best for your workplace.