A powder or foam fire extinguisher would be best for a BBQ fire
There are two options for tackling a barbeque fire.
Either a general-purpose powder extinguisher or the Firechief® Flame Buster Aerosol Extinguisher.
Both are intended to tackle fires involving grease and oil.
You can read more about these products and BBQ fires in our blog: BBQ FIRES: POWDER EXTINGUISHERS VS FOAM EXTINGUISHERS VS FIRE BLANKETS