FNH 200 Lecture Notes - Lecture 12: Flame Retardant, Median Lethal Dose, Waterborne Diseases
5 Jun 2019
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Document Summary
Terms : toxicants, toxicity and hazard, dose-response, risk-benefit concept. Contaminants become part of the food (foodborne and waterborne diseases) Human activities are responsible for them being in our food supply. Produce a whole spectrum of effects (minor death) Toxicity : ability of a chemical to damage a biological system. Any substance with ld 50 50 ppm/kg is considered poison. Hazard : probability that injury will result from use of a chemical at a given exposure. 1: probability of contact between substance & target object. Example: strychnine (plant from se asia), ld 50 = 1. 2 mg/kg. Extremely toxic chemical (only a small amount is needed severe effect in people) When sealed in an unopenable vial, can be handled freely by people with no chance that poisoning will occur. Example: boric acid (borax) , ld 50 = 1240 mg/kg. No hazard no contact can be established between the chemical and people. Added to foods in some cultures (firming agent, preservative, tenderizer)
