On the five seconds rule for dropped food

[elte]

http://medicalxpress.com/news/2016-09-de...teria.html

 The researchers tested four surfaces - stainless steel, ceramic tile, wood and carpet - and four different foods (watermelon, bread, bread and butter, and gummy candy). They also looked at four different contact times - less than one second, five, 30 and 300 seconds. They used two media - tryptic soy broth or peptone buffer - to grow Enterobacter aerogenes, a nonpathogenic "cousin" of Salmonella naturally occurring in the human digestive system.
Transfer scenarios were evaluated for each surface type, food type, contact time and bacterial prep; surfaces were inoculated with bacteria and allowed to completely dry before food samples were dropped and left to remain for specified periods. All totaled 128 scenarios were replicated 20 times each, yielding 2,560 measurements. Post-transfer surface and food samples were analyzed for contamination.
Not surprisingly, watermelon had the most contamination, gummy candy the least. "Transfer of bacteria from surfaces to food appears to be affected most by moisture," Schaffner said. "Bacteria don't have legs, they move with the moisture, and the wetter the food, the higher the risk of transfer. Also, longer food contact times usually result in the transfer of more bacteria from each surface to food."
Perhaps unexpectedly, carpet has very low transfer rates compared with those of tile and stainless steel, whereas transfer from wood is more variable. "The topography of the surface and food seem to play an important role in bacterial transfer," Schaffner said.

[scheherazade]

The single significant factor about where and when to apply this rule is how badly do you really, really want that morsel...

It also helps decide the matter if you have a sink and running water close to hand and if the morsel in question can survive a few seconds of water bathing.
Ice cream might be a loss, lol.

[Secular Sanity]

Carpet may be safer but it seems more disgusting than stainless steel or tile.  Maybe that because I associate it with hair.  We all think that finding a hair in our food is gross.  I looked to see how safe it was.  I’ll have to assume that the first article is more accurate since the FDA doesn’t place a limit on it, but it’s still gross.  I’d have to be literally starving before I’d finish eating something with a hair in it.  

Finding a hair in your spaghetti is gross, no question. But it is not, for the most part, a health threat. It's so benign that the Food and Drug Administration in its Food Code guidelines doesn't even place a limit on strands per plate. The FDA has received no reports of people getting ill from ingesting hair found in food.  {Source}

Hair is a source of microbiological contamination as the human scalp often contains Staphylococcus Aureus, a food poisoning organism. Therefore any hair in food can be a root cause of cross contamination and can indeed make us ill.  {Source}

https://en.wikipedia.org/wiki/Food_conta...ir_in_food