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My information is completely accurate, and I checked my calculations at least twice (on the back of an envelope, using the old fashioned method of multiplying and dividing with a pen and paper). (Because I actually learned to do math before there were calculators.) There is nothing irresponsible about providing exact and scientific information.

Thanks for providing me with more chuckles and reminding me how good it is to be retired and not having to deal with subordinates who sometimes seem to have no common sense. And I truly mean that... I have no animosity toward you. But rest assured I have had similar conversations in the past.

Please try to follow me on this... You just repeated that you carefully calculated that someone would have to drink 13 gallons of Visine to reach LD50. But I noted previously that most people will die if they drink less than 2 gallons of pure water in one sitting. The definition of LD50 is “the amount of a substance that is sufficient to kill 50 percent of a population of animals”. So while I am not questioning the method of your calculations I am still “guestimating” that your results are off by a factor of at least 6.5 times. This seems to be because of your inability to comprehend the big picture on this one and your focus on something that is almost meaningless in this conversation.

You and I both appear to have professional training. The difference seems to be that I was trained with the goal of identifying and evaluating and mitigating hazards to the public and my team from chemical and biologic agents. That was a big part of my job. Sometimes the primary hazards are much different than what the obvious calculations would indicate.

As far as what the point of your telling people in this conversation that they would have to swallow 13 gallons of Visine to reach LD50... at this point I really do not know what that is. Considering that there is a massive amount of data showing that people have had serious medical problems from ingesting just a few milliliters... you sound like someone who has become “out of touch” with reality.

I think you have a couple of issues going on. First, you read my science based assessment of the actual toxicity of tetrahydrozoline and jumped to all kinds of conclusions that had nothing to do with what I posted. Second, by reading your posts, I think you have a serious case of Dunning-Kruger going on--in your case, being that you know something about chem-bio hazards, but think your knowledge base is much greater than it really is.

You are both underestimating my position and my education. I suspect that you are doing so intentionally to try to put me down and pass yourself off as being much more knowledgeable than I (people have tried to do that before). I am a doctor of the Ph.D. type; I work in medical research where I supervise a number of Ph.D. scientists involved in toxicology research. So, rather than being some bachelor or masters level subordinate as you assume, I am the boss.

Do you really miss so completely the implications of my LD50 calculations as they pertain to the quantity of active ingredient in Visine?

I calculated the LD50 for a 75 kg human. It is a ballpark calculation, since I only have the data of an oral LD50 for mice, mice are not humans, and no one will ever calculate an LD50 in a human population. Okay, so the ballpark calculation is that ~25 g would be an LD50 in a 75 kg human. And calculating from that, I figured that it would take ~13 gallons of Visine to reach the LD50 of the active ingredient. Not of the buffered saline vehicle used to deliver the active ingredient, but of the active ingredient itself. What I am not saying, that you automatically assumed, is that someone could poison someone else by forcing them to drink 13 gallons of Visine. It's not going to happen. The take-home message that you *should* have gotten is that the volume of Visine required to deliver an LD50 of the active ingredient is so large that the idea of poisoning someone by putting a few drops of Visine daily into their coffee is far-fetched (to say the least). Could she have poisoned her husband with tetrahydrozoline? Yes, but not by using Visine. If she had access to the pure chemical, and if it didn't have a taste that would alert his suspicions, etc., she could have done it.

And who comes up with the information that you learned during your training, I wonder? Could it be people like me, who actually do the research in the chem-bio field to determine what the important facts are for you to know? Hmm.

Again, you seemed to have missed entirely the point of my LD50 calculation. I did it because I have doubts about the story as presented, and I was expressing those doubts. No doubt, when the trial takes place and the experts are called to testify, the entire picture will emerge. And probably will not be newsworthy, so we'll never know the details (unless we care enough about the case to look it up later, which I don't). For all I know, the medical experts in the trial will establish that he had "large amounts of tetrahydrozoline in his body" resulting from using Visine daily to moisturize his eyes--which means that he was swallowing it voluntarily, because the physiology of the eyes is such that everyone swallows eyedrops when they use them. And the wife will go home, exonerated.

And one other thing. You have described yourself as a first responder, and you have said more than once that you would never tell a patient that their dose was insignificant. Fine, I would not expect a first responder to have the knowledge or diagnostic tools available to make that determination. But you have heard of the term "worried well," haven't you? You've mentioned that some movie led to you having to respond to a number of copycat incidents. So people who saw that movie noted that the punch tasted funny, they saw an empty bottle of Visine nearby, and now they are having symptoms. How do you, as a first responder, differentiate their symptoms between "worried well" and actual intoxication? Especially since the symptoms might very well be identical in both cases? I don't think you do. That's for the medical people to decide, using information and tools developed by people like me.