Um ... that's not vitamin C. It's benzene, and it's curious, don't you think, that they don't say that sodium benzoate can become deadly when it's the combination of sodium benzoate is the other component in the reaction?
On another note, yes benzene is deadly in sufficient amounts but when this reaction was first discovered in the early 90's many if not most carbonated drinks contained vitamin C and sodium benzoate and I'm fairly no deaths resulted from 100's millions people (yourself, no doubt) drinking it. Still, benzene is a carcinogen, just like part of that crispy food you had for lunch today was carcinogenic, but rather than remove the sodium benzoate, which is man-made and already known to be poisonous by depriving oxygen from mitochondria, they blamed and removed the only good and natural thing in the drink: Vitamin C. There are more healthy preservatives than sodium benzoate that don't have this reaction with ascorbic acid, but somehow the nutrient got the blame instead of the poison, and sodium benzoate continues to destroy human health as a result.
Seems however, the biggest danger found in soda's both today and even back then (today NO soft drinks have the combination, nor have they for nearly 20 years) is all that high fructose corn syrup (can you say heart disease?), not to mention all the acid that has created generations of rotten teeth so bad to cause other health problems of currently epidemic proportions.
"Score big, eh eh?", "Is yea.", "Excelente'."
(igpay-atinlay of: "Ascorbic?","Yes.","Excellent.")
Short-form: "Score?", "Score." [knuckle bump]