Originally Posted by drainbamage
FWIW, heavy consumption of alcohol can also lead to oral, esophageal, and colorectal cancer, yet we all happily ingest it.
This is a HUGE point. The dosing rates that are required for most things to become problematic are many orders of magnitude over the normal dose. Alcohol, however, is toxic at much lower levels. For instance, if I were to take 5 times the recommended daily dose of Allegra one day, I would almost certainly be just fine. I would most likely suffer no ill effects from the overdose. I can speak to the truth of this statement, having done exactly this in the early human trials of the drug. I took 5 times what is now the over the counter dose for 2 weeks and had no problems whatsoever. BUT, if I was to take 5 times the recommended dose of alcohol, it would be toxic to me. The dosage window in which ethanol is 'safe' is very narrow compared to most other chemicals.
There is a neat series on Basic Brewing Radio called Homebrew Toxicology. It is a 3 part series where they cover everything from chemicals to lead. In the end they conclude that the overwhelmingly most dangerous thing involved in making homebrew is the production of ethanol. I suggest everyone give the series a listen, it was extremely interesting.
I will definitely read up on the cancer causing properties of the supposedly 'inert' ingredients in StarSan. However, it is also true that many things in excess will lead to cancer. The method of exposure can also make a large difference in the effects. Some things, like americium, have an extremely high risk of causing a cancer if ingested in a certain way (breathing), but very little if ingested in another way (eaten). From my research I have found that it is very rarely cut and dry when it comes to cancer, and the overwhelming problem is the inconsistency and reliability of the data. Environmental influences play a huge role in the available data, skewing the results. Two identical twins (same genes), living on two different sides of the country will likely not both come down with cancer. Why did the one twin develop cancer and not the other? It can't be genetics, so it must be environmental. Was it food, radon coming through his foundation, the mechanical hamster his daughter was rolling on his face while he slept? The answer is, nobody knows! Hopefully in another 100 years this will not be the case, but for right now, cancer is largely a trial and error field. My father is dying of bone cancer caused by the Agent Orange defoliant used while he served back to back tours in Vietnam. How do we know that is what caused his cancer? The extremely large amount of his fellow soldiers that developed the same problem. The medicine they are treating him with is 'cutting edge', but all that really means is that it has been found to work very well. They don't actually understand a great deal of why it works, just that it does. As the understanding of cancer itself increases the success rate of treatment will increase as well. I just wish that we were a couple hundred years more advanced in this goal than we are right now...
As with so many things in life, moderation is key. Too much of anything is likely to be bad for you. The tricky bit is figuring out how much of any particular thing is 'too much'.