Bio and SVO will take out the electric pump in the fuel tank first if the viscosity of the fuel is not up to diesel standards. If the tank pump goes, the high-pressure pump will follow suit and seize, which usually results in a snapped cam-belt, and you know where a snapped cam-belt leads you.
Some common-rail diesels are less tolerant of bio-diesel as the additives tend to damage rubber seals in the fuel system. Easiest way to find out if you are able to use it is to ask an Alfa dealer if it can be used or not. Most manufacturers state in their handbooks if they are compatable with biofuels.
Personally i wouldn't run the risk, i've seen the damage made to a Punto JTD engine after it lunched itself on bio.
03 Fiat Punto 1.2 Active, 2003 Vauxhall Vectra SRI 2.2 DTi