Rich, thank you for posting that. Even if standard detergents are not carcinogenic, there's still plenty of reasons to rinse the dishes considering that most detergents made here in North and South America will make the food taste worse if not rinsed properly.
As for how these rumors start, it's not just malice or ignorance.
I has a lot to do with the difference between food, drugs and stuff (in this case janitorial supplies) that does not fall under the categories "food" or "drugs".
I can tell you how I got the supposed "knowledge". It was in the mid-1990's, either a web site (like That Home Site) or a Usenet newsgroup. People were talking about how to wash "delicate" things like embroidered clothes and/or quilts. A lot of people offered their favorite way to do the wash, and a few people offered that they used "Orvus Soap". Orvus(tm) is a paste sold to farmers and people who own horses and similar animals. It's basically Sodium Lauryl Sulfate, supposedly easy to use to wash animals. Several people offered their opinions on using Orvus for such laundry tasks, pros and cons. A few people offered the opinion that they wouldn't use Orvus to wash something that could be worn next to babies skin because it was carcinogenic.
To my surprise, I followed the links that they offered to the Orvus MSDS and sure enough, they claimed that SLS "was listed by the State of California as a suspected carcinogen when ingested".
What I've learned recently, when you posted your entry, is that when you google for it, you'll find that some time ago there was a scare that some SLS which was not used for food, drug or cosmetics had been found to be contaminated by traces of dioxin.
I don't know if even that is true or not. But it does point out how much of a failure it is to give partial information to the population. People need to understand that just like mechanical parts can be manufactured to different tolerances, chemical compounds are manufactured to different tolerances too -- antibiotics meant to be used as eyedrops are much more refined (both more pure and ground more finely) that antibiotics in skin ointments, even if the ingredients list looks the same. SLS meant for medicines will be more pure than stuff in shampoos, which in turn will be more pure than stuff meant to wash dishes, clothes etc. That may explain why some janitorial cleanser was once long ago put on a list of suspected carcinogens.
That information may be long out of date and even not true anymore, if it ever was true. But when people in charge believe that the population at large is incapable of dealing with "complex" information, that's the system we get. To this day, things that are completely false still survive even in forums like this one. Go back and count the times we've seen "No Metals in the Microwave", for example. Not only it's false, it's part of the reason why people fail at properly using a microwave oven to cook -- they have no idea how to shield parts of the dishes with foil, when they can do it, how much metal can be in the microwave etc. Someone, possibly even well intentioned, decided "heck, it's too hard to summarize in a couple of minutes, I'll just tell them to never do it" and now we have a nation that can only reheat some kinds of leftover and nuke popcorn. Microwaving a simple meatloaf from scratch is beyond them. I have had people *eat* my microwaved meatloaf and refuse to believe it was nuked because "you can't brown anything with a microwave", which is also not true. All I can tell you is that I've seen MSDS floating around on the net in the mid-nineties claiming that Orvus paste (which is basically SLS and water) claiming it was known to the State of California as a suspected carcinogen when ingested. I expect that eventually that info will die -- I, for one, will not be saying that anymore. But I expect it will take considerable effort and time to make the rumor disappear. We still have people claiming that spinach has way more iron that it actually does, for example, despite the fact that a few years ago they discovered it was an erroneous bit of info due to a misplaced decimal period.
Again, thanks for the info.
