The problem with a “blanket rejection” of human data is that there may be sources of BPA exposure that are not modeled by stomach tube exposure in rats. After all, “[t]his isn’t how food actually enters our bodies. We chew it, move it around in our mouths…before it enters the stomach.” It turns out “that BPA can be completely absorbed directly into the bloodstream from the mouth,” thus bypassing instant liver detoxification. The same would be the case for BPA absorbed through the skin, which you can see at 2:08 in my video BPA on Receipts: Getting Under Our Skin.
Thermal paper, often used for cash register receipts, luggage tags, and many bus, train, and lottery tickets is 1 to 2 percent BPA by weight. Taking hold of a receipt can transfer BPA to our fingers, especially if they’re wet or greasy. Does the BPA then get absorbed into our system through the skin? Cashiers were found to have more BPA flowing through their bodies “[c]ompared with other occupations,” but that was based on only 17 people. “Strict vegetarians had lower urinary BPA concentrations compared with nonvegetarians,” but, once again, the sample size was too small to really make a conclusion. It’s been estimated that even cashiers handling receipts all day may not exceed the “tolerable daily intake” of BPA—however, that could change if they were using something like hand cream.