Worse, Joe: I was watching a consumer's programme on Swiss TV last
night. Apparently, a prof. at Columbia university has discovered that
some babies' feeding bottles in polycarbonate transfer infinitesimal
quantities of bisphenol A to the contents. This is claimed to cause
hormonal development problems to the baby, creating overgrowth and
obesity to the infant, as "proved" in rodents (no mention of dosology or
metabolic paths, necessary in serious toxicity or epidemiological studies).
As a result, polycarbonate bottles are now being forbidden in Canada.
The programme anchor, who is an anti-everything by nature, then bought n
bottles in Switzerland and had a German lab (more serious than a local
one, of course) determine which ones were in PC, which in other unnamed
plastics and which in glass. The majority were in PC. However, she
reported no figures of BPA leaching, so all the PC ones were condemned
without trial. She recommended that mothers use only glass (why not,
anyway???). BTW, no thought about the titties that actually go in the
childrens' mouths and what they may be made of!
She then interviewed a so-called expert, a professor in some obscure
university, I think in France or Belgium, who claimed that BPA was one
of the worst chemicals in existence, carcinogenic to umpteen organs,
mutagenic, teratogenic, endocrine upsetter, neurotoxic, reproductive
toxic and causes nearly every other disease known to man, including
Alzheimer's and Parkinson's (yes, he recited this list except the every
other disease bit which I added). No mention of dosages, though. Now for
the bad news: this guy claims to have the ear of the EU and wants BPA
and products made with it banned throughout the Union.
That means all polycarbonates, epoxies and some copolymers are currently
under scrutiny. No DVDs or CDs, no FR-4 or epoxy adhesives, no PC
monitor cases, no plastic glazing or greenhouses, no cars, no aircraft,
no polycarbonate capacitors, no FR-4 of any flavour etc... Back to our
caves, guys!
Now, a wee bittie of simplistic chemistry. To make FR-4, a mixture of
BPA and its brominated homologue TBBPA is reacted with epichlorohydrin
in the presence of sodium hydroxide to form the basic prepolymer, which
is treated in various ways to eliminate most of the sodium chloride
which is formed. Theoretically, there is no free BPA/TBBPA left if the
proportions are stoichiometrically correct. This prepolymer is then
reacted with a crosslinking agent which joins up the linear liquid
prepolymer, via the epoxy groups in the molecules into a
three-dimensional polymer. In the case of polycarbonate, it is formed
by a similar condensation reaction with BPA, often admixed with TBBPA.
If there is any free BPA or TBBPA, it is because either a) there is an
excess beyond the stoichiometrical ratio or b) the polymerisation
reaction is incomplete. b) is easy to control but a) less so but a) can
be stopped by adding a very small excess of its reactant,
epichlorohydrin in the case of epoxies, so that it is all reacted. As
the latter is volatile, any excess will be eliminated during the curing
process or any subsequent heating. I maintain that it is not necessary
for polycarbonate or epoxy resins to have excessive quantities that can
leach out, but it will require better process control, but it is much
easier to prevent the problem by banning BPA and its brominated derivative!
For those who understand French, you can see the report at
http://www.tsr.ch/tsr/index.html?siteSect=500000&bcid=590635#bcid=590635;vid=9199328
(if the URL is split, don't forget to join the lines)
Also
http://www.tsr.ch/tsr/index.html?siteSect=311201&sid=9198628&page=1#title
for a summary
I hope this is nothing more than a storm in a baby's bottle!
A bon entendeur, salut!
Brian
Joe Fjelstad wrote:
>
> for your consideration...
> Joe
> http://www.edn.com/blog/570000257/post/1740027974.html?nid=3357&rid=208605613
> Tuesday, June 10, 2008
>
> Flame retardants ignite controversy
>
> Jun 10 2008 7:31AM
> Accurate figures are difficult to obtain, but it has been estimated that
> fires kill around 10,000 people a year globally, in which the cause is
> attributed to faulty electrical wiring in buildings and in electrical equipment. Flame
> retardants have been used very effectively in a wide variety of electrical
> equipment to prevent fires, reduce their seriousness and also to delay onset to
> allow people more time to evacuate. In fact, research has shown that when
> flame retardants are used as additives to plastics, the amount of time to
> escape is increased by 15 times. Since they were introduced, thousands of lives
> have been saved, and so there is no doubt about their value.
> Many types of plastics burn very easily. It has been estimated that the
> plastics in a typical TV set are equivalent to 1.5 gallons of gas, not something
> consumers want in their living rooms! However, only around 12% of plastics
> contain flame retardants. Some types are inherently resistant to fire, such as
> rigid PVC, and so do not need flame retardant additives. Some equipment is
> not at risk such as battery powered products like mobile phones because of the
> low voltages used, and therefore flame retarded plastics are not needed.
> Mobile phone battery chargers, however, do need to have flame retardants as they
> are powered at standard voltages, and so arcing and high temperatures can
> occur if there is a defect.
> But BFRs (brominated flame retardants) are now at the center of considerable
> debate. The review of the ROHS directive, undertaken by the German
> organization Oko on behalf of the European Commission, is looking at a significant
> number of them, along with 46 other chemical compounds, and may well recommend
> the restriction of some, or all of them.
> So, why will they be banned when many have already been tested, and it was
> concluded that they pose no threat to human health and the environment?
> Well, Oko is recommending a ban on all organobromine and organochlorine
> compounds, including brominated flame retardants because of �backyard recycling�
> of WEEE (Waste Electrical and Electronic Equipment) in countries that do not
> have the know-how, or facilities, to dismantle safely.
> The toxic fumes created by backyard and roadside fires are having a
> significant affect on human health, even causing death.
> While the Basel Convention should stop the shipping of WEEE to such
> countries, a lot of the scrap still comes from the likes of the United States, which
> has not yet ratified it.
> Flame retardants seem a classic example of a need for a risk-benefit balance
> based on assessments that the ROHS directive and REACH regulations were
> designed to resolve. It�s a trade-off between safe furniture, fabrics, and
> electronics or the fatalities caused in the poorer villages of China, India, and
> Africa.
>
>
>
>
>
>
> **************Vote for your city's best dining and nightlife. City's Best
> 2008. (http://citysbest.aol.com?ncid=aolacg00050000000102)
>
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