Bisphenol A Lucas Stoiber CBE 555 Oct. 7 th 2008.

Bisphenol A

Lucas StoiberCBE 555Oct. 7th 2008

What is Bisphenol A?

BPA First synthesized in 1891

Condensation of acetone with phenol In 1930s it was found to be an artificial

estrogen (similar to DES)

BPA in plastics

In the 1940s and 1950s it was discovered that BPA can be used in the synthesis of polycarbonate and epoxy resins (#7)

Currently over 2 million tons are produced world wide

In the U.S. it is made by Bayer, Dow, GE, Hexion, and Sunoco

Also used as a polymerization inhibitor in PVC (#3)

Epoxy resin

Epoxy is produced from a reaction between epichlorohydrin and bisphenol-a

Where do we find BPA?

Common uses

Dental sealants CDs Eye glasses Food and beverage can coatings Reusable water and baby bottles Film Water pipes and sealants in water towers Etc.

Possible health concerns

BPA is an endocrine disruptor

An endocrine disruptor is a chemical that mimics hormones

Potentially causes problems with the reproductive system

Our Stolen Future

Animal Studies

Animal studies have shown that low doses of BPA can cause breast cancer, testicular cancer, diabetes, hyperactivity, obesity, low sperm counts, miscarriage and a host of other reproductive failures.

Shown at concentrations as low as 2 μg/kg/day in mice

Hundreds of studies show that BPA is harmful in animals

Human Issues

BPA leaches from the plastics 93% of Americans tested had BPA in their

urine Highest intake levels in infants Average levels between 0 and 14

μg/kg/day

Government Reactions

Certain phthalates have been banned from toys and other objects used by infants and toddlers in the EU, Japan, Mexico, and California

Mainly in PVCs BPA is not one of these

Canada

In April 2008 Health Canada classified BPA as toxic to human health and the environment

Announced intent to ban the import, sale, and advertisement of polycarbonate baby bottles containing bisphenol A

Companies respond

Wal-Mart imediately stopped sales in all its Canadian stores of food containers, water and baby bottles, sippy cups, and pacifiers containing BPA. Promised to do the same in the U.S. by 2009

CVS, Toys-R-Us, Nalgene, Playtex and others promise to remove BPA

U.S. Legislation

Charles Schumer (D-NY) introduced a bill to the Senate to ban BPA in children’s products (Bill # S.2928)

Edward Markey (D-MA) introduced a bill in the house to ban BPA in food and beverage containers (Bill # H.R.6228 )

FDA

The FDA evaluation only uses tests where the BPA is ingested

Assumes that BPA is much more easily metabolized by primates than mice

Determined the No Observable Adverse Effect Level to be 5 mg/kg/day

The tests used tend to favor tests performed by industry

Other agencies

The European Food Safety Authority established the Tolerable Daily Intake to be 50 μg/kg/day

Japan has said there is no risk Canada now states that BPA does not

pose a risk

National Toxicology Program findings

Lang Study

First human study Higher concentrations of BPA in urine

were associated with higher prevalence of heart disease, diabetes, and liver-enzyme abnormalities.

Lang, I. A. et al. JAMA 2008;300:1303-1310.

Estimated Mean Bisphenol A (BPA) Concentrations in Relation to Reported Diseases and Conditions

Alternatives

Copolyesters no alternative that works as well to prevent

spoilage and extend shelf life for canned foods as the BPA epoxy resins used in can linings

Conclusions

More testing needs to be done Impossible to avoid at this point Breast feed infants if possible, otherwise

use glass or BPA-free bottles

References http://www.jsonline.com/index/index.aspx?id=305 http://www.bisphenol-a.org http://www.fda.gov/ohrms/dockets/ac/08/briefing/2008-0038b1_01_02_FDA%20BPA%20Draft%2

0Assessment.pdf http://www.chemicalsubstanceschimiques.gc.ca/challenge-defi/bisphenol-a_fs-fr_e.html http://jama.ama-assn.org/cgi/content/full/300/11/1303?maxtoshow=&HITS=10&hits=10&RESULT

FORMAT=&fulltext=bisphenol+a&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT http://jama.ama-assn.org.ezproxy.library.wisc.edu/cgi/content/full/298/13/1499?maxtoshow=&HIT

S=10&hits=10&RESULTFORMAT=&fulltext=bisphenol+a&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

http://jama.ama-assn.org.ezproxy.library.wisc.edu/cgi/content/full/300/11/1353?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=bisphenol+a&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

http://en.wikipedia.org/wiki/Bisphenol_A http://www.ada.org/prof/resources/topics/bisphenola.asp http://www.ewg.org/reports/bpatimeline http://www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_BisphenolAFAQs.htm http://www.congress.org/ http://www.factsonplastic.com/ http://www.niehs.nih.gov/news/media/questions/sya-bpa.cfm

Other stuff American Chemical Council states an average adult

consumer would have to ingest more than 230 kilograms (or about 500 pounds) of canned food and beverages every day for an entire lifetime to exceed the safe level of BPA set by the U.S. Environmental Protection Agency

American Dental Association believes any concern about potential BPA exposure from dental sealants or composites is unwarranted at this time. When compared with other sources of BPA, these dental materials pose significantly lower exposure concerns.

Environment Canada states that BPA in the environment can harm fish and other organisms

Some professors suggest that PVCs will go the way of asbestos and lead

Dose(µg/kg/day)

Effects (measured in studies of mice or rats,descriptions are from Environmental Working Group)[42][34]

Study Year

0.025 Permanent changes to genital tract 2005[43]

0.025Changes in breast tissue that predispose cells to hormones and

carcinogens2005[44]

2 increased prostate weight 30% 1997[45]

2lower bodyweight, increase of anogenital distance in both

genders, signs of early puberty and longer estrus.2002[46]

2.4 Decline in testicular testosterone 2004[47]

2.5 Breast cells predisposed to cancer 2007[48]

10 Prostate cells more sensitive to hormones and cancer 2006[49]

10 Decreased maternal behaviors 2002[50]

30Reversed the normal sex differences in brain structure and

behavior2003[51]

50U.S. human exposure limit (not a result from an animal study,

but a guideline set by EPA)1998[52]