Ask HN: Is Subway Food Safe?

http://naturallysavvy.com/eat/this-is-why-sodium-benzoate-is-so-scary

http://www.subway.com/~/media/usa/documents/nutrition/usprodingredients.pdf

I saw that Sodium benzoate when mixed with citric acid or ascorbic acid can lead to creation of some cancer causing elements.

How safe is having food in subway since these ingredients seems to have these chemicals.