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oBut American Congress passed a special bill allowing the sale of saccharinHuman would have to drink the equiv of 800 cans of diet drinks to equal the amount of saccharin that caused cancer in test rats…oOne cannot extrapolate animal studies automatically to humans Risk vs. Hazard/ToxicityChemicals can be toxic or hazardous, no doubtoBut do they automatically present risk?Analogy: No doubt that a lion presents a hazardoBut the risk is not necessarily there…oIf you meet him in the zoo, hazard stays the same but the risk is lesseroRisk = Hazard x ExposureSo for chemicals, risk is associated to both the toxicity of the material as well as exposureRisk is very small if there is little exposure!Also have to factor in susceptibility!So risk = Hazard x Exposure X Susceptibility oE.g. antelopes very susceptible to getting killed by a lion, mouse not reallySaccharin wrt to humans:oHazard is there, but not too much risk
World of Chemistry – Chem 181Midterm 2 Notes Saccharin banned as a food additive in Canada, made available as tabletop sweetener in pharmacies only but was available as tabletop sweetener with warning labelFurther studies showed that saccharin leads to cancer in male rats by a mechanism not found in humansoSo always remember this aspect of susceptibility! oRisk associated with hazard, exposure, and susceptibility oHumans not susceptible to saccharins cause mechanism not thereIn 2000: FDA removed ban on saccharins and now it is fully allowed in US oStill not allowed as food additive in Canada, but free for all in US SorbitolMany OH groupings in this molecule (6)These compounds are known as poly-alcoholSorbitol has relative sweetness of 0.6 – much less sweet than saccharine2.6 caloriesUsed in diet productsIs very slowly metabolized by body Recommended for carbohydrate-reduced dietsSits in colon, and can ferment there explosive diarrheaXylitol5 OH groupings in its structureRelative sweetness = 12.4 calories Xylitol present in sugarless gum oUnlike sugar, does not promote tooth decayoBy chewing this sugarless gum, increases salivation and dilutes acid which causes tooth decay oTrident contains xylitol and sorbitolo“4/5 dentists surveyed recomment sugarless gum for their patients who chew gum”Have to put 4/5 or 9/10 to account for the possibility that a dentist wouldn’t agreewith them, this is a way for companies to protect themselvesoExcessive use of Xylitol may have a mild laxative effectCyclamateDiscovered accidentally by Michael Sveda in 1937 He was smoking in the lab, and when he picked up his cigarette, noticed that the tip had a sweet tasteRealized that the cigarette had laid next to compounds he had been working on, and gave sweetness that was responsible for sweetnessoThe compound = cyclamateCyclamate in terms of sweetness if 30 times sweeter than sugar, btut is non-caloric