Answer : The Carriage of Dangerous Goods and use of Transportable Pressure Equipment Regulations 2004 (CDG), as amended by The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment (Amendment) Regulations 2005 require that petrol should be carried in UN approved containers (called Packages), which are properly stowed on the vehicle. The packages should be marked with the "flammable" diamond and with the UN number for petrol (UN 1203). Up to 333 litres may be carried as a "small load" which means that only general training needs to be given to the driver and that the vehicle only needs to carry 1 2kg fire extinguisher. These regulations do not affect purely private carriage.
Any vehicle involved in work activity and carrying more than 333 litres should be fitted with appropriate hazard warning signs and the driver should receive specialised training. The vehicle should carry specific fire extinguishers and a dangerous goods safety adviser should be appointed.