Canada first to label
bisphenol A
as officially dangerous
Would pave way for federal ban
Martin Mittelstaedt
The Globe and Mail (Canada)
April 16, 2008
http://www.commondreams.org/archive/2008/04/16/8330/
Under normal use, bottles made of polycarbonate,
like those above, will leach meaningful amounts
of bisphenol A. Bisphenol A, or BPA, is one of the most
widely used synthetic chemicals in modern industry.
It is the basic building block for polycarbonate,
the see-through, shatter-proof plastic that resembles
glass, and is also used to make the epoxy resins
lining the insides of most tin cans, along with some
dental sealants, sports helmets and compact discs.
Canada has taken the first step in banning the
substance in certain products.
Health Canada is calling bisphenol A a dangerous substance, making it the
first regulatory body in the world to reach such a determination and taking
the initial step toward measures to control exposures to it.
Although the government won’t announce specific bans or restrictions, the
designation as dangerous could pave the way for the hormonally active
chemical to be listed as toxic under the Canadian Environmental Protection
Act, which would allow Health Minister Tony Clement to issue specific
measures to curb its use.
Bisphenol A, or BPA, is one of the most widely used synthetic chemicals in
modern industry. It is the basic building block for polycarbonate, the
see-through, shatter-proof plastic that resembles glass, and is also used to
make the epoxy resins lining the insides of most tin cans, along with some
dental sealants, sports helmets, and compact discs.
Experts are worried about BPA in food and beverage containers. Products
such as CDs aren’t considered a problem.
“Bisphenol A is in every Canadian home. It threatens the health of every
Canadian. Moving against it would be a hugely significant victory for public
health and the environment,” said Rick Smith, executive director of
Environmental Defence, a group that has been campaigning for a ban on the
chemical from food containers.The conclusion by Health Canada that BPA
is a possible threat, expected to be announced as early as tomorrow, will
amount to one of the most important regulatory decisions regarding a single
chemical in decades, and will put pressure on its counterparts at both the
European Union and the U.S. Food and Drug Administration to reconsider
their approval.
“If this chemical is listed as toxic [by Health Canada], it will be an
internationally significant decision,” Mr. Smith said.
Under Health Canada’s regulatory approach, the government department,
along with Environment Canada, is expected later this week to release a draft
assessment indicating that bisphenol A endangers people and the
environment. The document outlining this finding will be open for a 60-day
public comment period. If no new information is made available through
the consultation to overturn the finding, the government will issue a final
report outlining control measures within a year.
The government had a deadline of mid-May to issue its BPA assessment but
is moving earlier because of intense public interest.
The expected announcement will also win the Harper government praise
among environmentalists, who have been harsh critics of the Conservatives’
approach to climate change but will find it hard to criticize groundbreaking
action on a chemical pollutant.
U.S. tests have found that more than 90 per cent of the population carries
in their bodies trace residues of the chemical, whose molecular shape allows
it to mimic the female hormone estrogen. Small amounts of BPA can leach
from food and beverage containers during use, such as when they are heated,
exposed to harsh dishwashing chemicals, or contain acidic substances.
Health Canada is testing Canadians’ BPA levels, but the results will not be
available for several years.
In response to concerns over the safety of BPA, many specialty retailers,
including Mountain Equipment Co-op, have pulled polycarbonate plastic
containers from their stores, and BPA-free bottles are been flying off shelves,
creating shortages. Hudson’s Bay Co. announced last month that it
had “secured large quantities” BPA-free baby products, a sign of how quickly
even the mass market has moved against the chemical.
Independent researchers in dozens of studies have linked trace BPA exposures
in animal and test-tube experiments to conditions involving hormone
imbalances, including breast and prostate cancer, early puberty and changes
in brain structure, particularly for exposures during key points of fetal or
early neonatal development.
However, industry-funded testing has been unable to confirm these findings.
The trade association representing major manufacturers, the American
Chemistry Council. based in Arlington, Va., submitted two studies to Health
Canada during its assessment indicating BPA has no harmful effects at low
doses.
Until now, regulators in other countries have accepted the industry’s
assertion that BPA is harmless at the tiny, parts-per-billion type exposures
from canned food and plastic beverage containers. A part per billion is
roughly equal to one blade of grass on a football field, although natural
hormones such as estrogen are active at far lower concentrations, around a
part per trillion.
Look for the 7 in a triangle
Polycarbonate is sometimes identified by the recycling industry’s symbol of
the number seven inside a triangle, with the letters PC nearby.
Canada takes stance on BPA
A U.S. study found that more than 90 per cent of people carry trace amounts
of the chemical in their bodies. The Canadian government is expected to
announce as early as tomorrow that it is a dangerous substance.
What is it?
Used to make polycarbonate plastics and epoxy resins. Common items:
• Baby bottles
• Flatware
• Watercooler bottles
• Liners for food and beverage cans
• Seals for cavity-prone teeth
Polycarbonate plastic tends to leach bisphenol A with age and after heating.
What does it do?
Bisphenol A (BPA) is a compound that mimics estrogen, which can disrupt the
endocrine system and could induce adverse hormonal responses. Studied
effects on animals give rise to fear that low-level exposure might cause
similar effects in human beings.
Possible effects
• Permanent changes to genital tract
• Increase prostate weight
• Decline in testosterone
• Breast cells predisposed to cancer
• Prostate cells more sensitive to hormones and cancer
• Hyperactivity
The process
NORMALLY
1. Estrogen binds with its receptor
2. Estrogen and receptor cause a biological response
WHEN BPA IS PRESENT
1. BPA binds to and reacts with the estrogen receptor
2. BPA and receptor cause a biological response
BPA IN CANNED FOOD
Source: Environmental Working Group, Environmental Defence
