Rick

I don't think that anyone who has given a serious and impartial thought to the
issue would disagree with you.

However, I'll allow myself to go somewhat off-topic and discuss bromine. There
is a move afoot to eliminate tetrabromobisphenol A (TBBPA) as the flame
retardant component in FR-4 laminates (and polycarbonates), also driven mainly
from Europe (substitute flame retardants are available but all of them exhibit
some severe disadvantage, compared to TBBPA). As TBBPA represents about 25% of
the consumption of bromine, this is driving the bromine industry nuts. Over the
past few years or so, they have been trying to find a substitute market for
their bromine and have developed a solvent called nPB (n-propyl bromide,
1-bromopropane) which is being very aggressively marketed. nPB has an
ozone-depleting potential that the best current estimates average at 0.027 but
peaks to 0.11, according to latitude of emission. The former figure compares
with some regulated substances under the Montreal Protocol and the latter figure
to 1,1,1-trichloroethane (methyl chloroform, Chlorothene) which has been banned
under the Protocol in developed countries since 1996. However, nPB has escaped
introduction into the Protocol through some technicalities, at least up to the
end of 2001 and possibly later. It has also escaped reporting in the USA into
the Toxics Release Inventory and, pending SNAP approval (which would seem
conditionally likely in 2001), is freely available for unrestricted sale. It has
taken the US EPA three years not to determine the SNAP approval, even though it
would appear to be at least as toxic as non-ozone-depleting chlorocarbon
solvents, although the manufacturers claim a much lower toxicity with an OEL of
100 ppm. A Japanese study has shown strong evidence of neurotoxicity and a
slight evidence of reproductive toxicity in rats at continuous dosage over 4 -
12 weeks at 200 ppm and an epidemiological study in humans of an isomer, iso-PB,
has shown a severe reduction of sperm count and mobility in persons exposed to
the solvent in an industrial environment. As a precautionary measure,
toxicologists usually give an OEL of 1/10th the lowest value exhibiting harm in
animals, so the logical maximum value for nPB should be 20 ppm and not the 100
ppm the bromine manufacturers claim. OSHA have requested an evaluation by the
National Toxicology Program, which cannot be completed before the end of 2003
and thus an "official" OEL/PEL/AEL cannot be decreed for years, yet. In the
meanwhile, any Tom, Dick or Harry can buy the solvent and use it for defluxing
PCAs almost without any let or hindrance. OK, it is not compatible with the
tenderer plastics, such as PC or PS, but it is pretty good for most hybrid
assemblies, and there are special blends for the electronics industry. I do not
claim that this development has been sparked by the writing on the wall for
TBBPA but it must surely have been accelerated. So, eliminating an environmental
problem has partially accelerated another one, combined with a potentially
severe toxicological one. Incidentally, I have been given to understand that the
caution exercised by the EPA to not give SNAP approval has been the result of
intense lobbying pressures by the US bromine industry, the world's largest one,
just now, whose main production happens to be in Arkansas.

From the frying pan into the fire, like lead-free electronics????????

Brian

Rick Etchells wrote:

> Please forgive me if this offends anyone, that is not my intent.
>
> I have been reading the messages on this mailing list and on this
> topic for a longtime and for the most part I have kept silent.
> However, I really get upset by those who keep telling us that it is
> too late to turn back now and we might as well just give in and do
> something that we have good reason to believe is wrong.  It is never
> too late to stand up for the truth.
>
> It is crazy to concentrate on the 1% or less of the lead used in
> electronic solder and to basically ignore the big lead problems like
> CRT's and batteries.
>
> It is even more crazy to replace this 1% with materials that could
> potentially be even more hazardous to the environment.
>
> Then to do so because of marketing reasons and because we believe the
> ball is rolling to fast is just wrong, wrong, wrong.
>
> Each of us has a responsibility to stand up for what we believe to be
> the truth.  We can make a difference, particularly if the
> organizations that we belong to such as the IPC, IEEE, IMAPS, SMTA.
> etc. will promote a fair evaluation of both sides of the issue based
> on facts.  I hope that the rumor that the IPC is considering
> reevaluating its position is true.  I never liked their approach of"
> it's inevitable so we might as well bite the bullet and give in".  If
> they do carry through with a reevaluation I for one will applaud them.
>
> Rick Etchells
>
> "Any Science, we should insist, better than any other discipline, can
> hold up to its students and followers an ideal of patient devotion to
> the search for objective truth, with vision unclouded by personal or
> political motive."  - Sir Henry Hallett Dalt
>
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