The National Fire Prevention Association has stated that, vinyl and aluminum siding create a fire hazard by keeping fire inside your house, intensifying the heat and literally turning your house into a furnace! It also creates serious problems for firefighters because it makes it difficult to locate the source of a wall fire.
When vinyl siding burns, it releases toxic gasses and creates acidic smoke. The acidic smoke is so strong, it can kill a person inside the house before the flames or carbon monoxide.
The following links contain more detailed information about the hazards of vinyl siding.