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the BPA probably penetrated deeply
into the skin, perhaps as far as
the bloodstream.
The Swiss team estimates that most
people would not receive more than
about 2. 5 percent of the tolerable daily
intake of BPA from handling a single
receipt. But under a worst-case scenario—a pregnant cashier who wore
hand cream that boosted BPA’s permeability — someone might well sustain
exposures that approached 50 micrograms per kilogram body weight, which
is what European and U.S. regulatory
agencies estimate as a tolerable intake.
“I think it’s a scandal that you can have
people touching thermal paper all day
long,” Grob says, since its surface coating could approach 10 percent BPA.
Frederick vom Saal of the University of Missouri in Columbia, who performed BPA assays for a recent study by
the Washington, D.C.–based nonprofit
Environmental Working Group, agrees.
“I won’t touch receipts now,” he says.
The EWG study found BPA in 32 of
39 receipts collected from retailers in
Washington, D. C., seven states and a city
in Japan. Sixteen of the U. S. receipts contained substantial quantities of BPA, on
average 1. 9 percent by weight, the group
reported July 27.
Solvent layer
Hot stylus
Colorless dye Activated dye BPA activator
Here’s your receipt In thermal paper
receipts, a colorless dye is embedded in a
solvent layer along with an activator — often
bpa — that causes the dye to darken. heating
the solvent layer allows the reaction to occur.
In follow-up studies, vom Saal has
confirmed the same wet-versus-dry dif-
ference in transfer of BPA to fingers that
was demonstrated by the Swiss group.
Plus, vom Saal says, “we saw something
they didn’t report: that the longer you
hold a thermal receipt, the greater BPA’s
transfer to your fingers.”
Scientists at the National Institute of
Environmental Health Sciences’ National
Toxicology Program have followed the
emerging data on BPA in thermal paper.
“We’re exploring the feasibility of looking
at how much [this paper] is contributing
to exposures in people known to handle
receipts frequently,” says Kristina Thayer
at NTP in Research Triangle Park, N.C.
Such investigations might include testing
Back Story | WHERE TO FIND BPA
aside from cash register receipts, bisphenol a is often found in products that contain polycarbonate plastics and epoxy resins.
common products that may contain bpa include:
Plastic baby and water bottles
retailers and manufacturers have been switching to bpa-free plastics, but it can be difficult
to tell if a bottle contains the compound
unless it is specifically labeled as bpa-free.
Plastic food storage containers
the u.s. Food and drug administration
approved bpa for use in food containers in
1963, more than a decade before federal law
required safety reviews for new chemicals.
Compact discs and DVDs
bpa-containing polycarbonate plastic is used
in compact discs and dVds for its sturdiness
and flow properties when molten.
Food and beverage can liners
cans are often lined with epoxy resins to
keep the contents fresh. until recently,
virtually all can linings contained bisphenol a,
but some companies have introduced
bpa-free cans.
to measure how well and how far BPA is
absorbed through the skin and what conditions might influence that.
On July 15, the Environmental Pro-
tection Agency launched a BPA Alterna-
tives in Thermal Paper Partnership. The
program is recruiting paper companies,
receipt-paper retailers, environmental
groups, chemical companies and trade
organizations to brainstorm ways to
move “towards safer alternatives.”
Appleton Papers of Appleton, Wis.,
switched to one of them — bisphenol sul-
fonate — in 2006, says company vice presi-
dent Kent Willetts. EPA’s new partnership
program lists the sulfonate as a potentially
acceptable substitute, he notes.
But, vom Saal observes, there’s little way for a consumer to distinguish
between receipts with and without BPA.
They look identical.
“Frankly,” Willetts says, “there hasn’t
been much awareness outside of the sci-
entific and thermal-paper communities
about this issue. So there was little out-
cry asking how to identify our paper.”
The good news, Feinstein says, is that
some paper companies have recognized
the problem. “These companies should be
commended, and it is my hope that con-
sumers will demand that other compa-
nies voluntarily follow suit.” s
top: t. mendum et al/green chemistry letters and reviews 2010, adapted by t. dubÉ; back story, cLock WIse From top LeFt:
onebLueLIght/Istockphoto; markgoddard/Istockphoto; FotograFIabasIca/Istockphoto
Dental sealants
several studies have found traces of bpa in
saliva immediately after the application of
dental sealants.
Impact-resistant plastics
polycarbonate plastics are used in safety
helmets, bulletproof glass, traffic signals,
computer cases and a wide variety of other
applications where bpa exposure is unlikely
and of little or no public health concern.
