Wikipedia has more on Toxiphobia.
Toxiphobia (less commonly known as iophobia) is a fear of being poisoned. Despite poisoning is a minor problem in the United States and other developed countries, it gets significant coverage when poisoning was reported, lending people to think that poisonings are common or even unavoidable, causing depression that becomes fear. Another cause of fear is the one who was poisoned and survived.
A primary symptom of toxiphobia is suspicion, meaning sufferers would not trust a friend to cook food for them and give them a drink because sufferers may worry that a friend may add toxins to it. Toxiphobes may trust grocery stores, but not restaurants, cafeterias, and food stops.
Toxiphobia can be treated by having therapists to teach patients that obsession with potential poison may be unhealthy, then teach them reasons that toxins found in food and drink are very scarce. This would help relieve their fears and increase trust in others. Like Benziphobia, It branches from both Emetophobia and Thanatophobia.