Howdy Joe (I just had to write "Hey Joe" before. its the lead to a
Jimmy hendrix song I enjoy.)
more below
Joe Street wrote:
Hi Bob; see comments below.....
bob allen wrote:
Hey Joe,
Joe Street wrote:
Where is the toxicology?
For those on the list unfamiliar with MSDS (Material Safety Data
Sheet) and the terminology this is what is missing
no LD50 (lethal dose for 50% death rate -usually tested with rats)
no LC50 (lethal concentration for 50% death rate)
There may not be data on sodium methoxide due to its reactivity: in
the body it quickly (essentially instantaneously) equilibrates to
sodium hydroxide and methanol.
Well I don't know if it is that simple.
for my example yes. when you combine sodium or potassium hydroxide with
methanol, you establish an equilibrium:
sodium hydroxide + methanol --> sodium methoxide + water
addition of water such as occurs in vivo, forces the equilibrium back to
the left.
For example I am familar with
TMAH (TetraMethylAmmonium Hydroxide) which is essentially Methanol and
Ammonium Hydroxide
no, not by a long shot. Tetramethylammonium hydroxide has a formula of
C4H13NO. It is chemically quite different than a mixture of ammonium
hydroxide (it self an equilibrium mixture of water, ammonia and ammonium
hydroxide) and methanol.
which is used as a modifier in semiconductor chemical
etching processes. The MSDS lists a drastically different toxicity for
the METHANOL component approx 5000 ppm vs the TMAH at only 25 ppm.
See: http://www.jtbaker.com/msds/englishhtml/t1816.htm
I am no chemist
I am
and I don't know if it is fair to make this comparison
since
not here
we are talking about ammonium hydroxide instead of potassium
hydroxide but clearly the compound is much more toxic than the sum of
its components.
you're comparing oranges and apples. I spoke of a simple mixture
NaOH/MeOH and you are talking about a compound (CH3)4 N (+) (OH)-
and more importantly
no TLV (Threshold Limit Value which relates to the maximum allowable
exposure before serious health effects appear due to daily repeated
exposure)
no OEL (Time Weighted Average (TWA) which refers to what someone
decides is an acceptable concentration which a worker can be exposed
to over a working shift time period)
TEL and OEL as far as I am aware relate only to volatiles. Sodium
Methoxide is a hygroscopic solid, hence no data.
The methoxide that I make by mixing 99% methanol with 85% assay KOH is
volitile and definitely liquid.
You are making a mixture, the volatile component of which is still methanol
So I would think it should be of
interest. The datasheet we found for sodium methoxide refers to a solid
you are right but that just shows the relevance of the comments from
before that one must know something in order to even read an MSDS and
even then it may be of limited value. You are right though it is still
the best info we have. I just think it is sad that the documentation
does a very poor job of what the legislation ( or the intent behind the
legislation) was supposed to accomplish which is to provide meaningful
information to protect workers who have to handle hazardous subtsances.
If you dug around long enough you may find a supplier of the mixture you
are preparing. If they sell that mixture, then they have to have a MSDS
on it.
In this case (methoxide solution), use the methanol component msds for
things such as an LD50 or TLV and the NaOH or KOH msds for other risks,
such as extremely caustic, etc.
It is an echo of the type of situation so often discussed in this forum
where legislation which is supposed to protect people ends up having
gaps and loopholes that allow big industry to go on with little more
than a nod to regulations and the rest is status quo. Still it is better
than no information. But not much better. I have worked with
proprietary formulations of liquid teflon from dupont which required so
many promises of non disclosure and confidentialty you would almost
wonder if they really want anyone using the stuff and then when you
finaly get it and read the MSDS it tells you there are proprietary
elements which are undisclosed. The technical information sheet
included with the bottle gives explicit instructions on how much exhaust
and protective equipment is needed and leaves you with a sense of fear
of the unknown, but yet there it is on the market for anyone who can
afford it. Lip service. That's all it has become. Business as usual.
no real disagreements here...
toodles
--
Bob Allen
http://ozarker.org/bob
"Science is what we have learned about how to keep
from fooling ourselves" — Richard Feynman
_______________________________________________
Biofuel mailing list
Biofuel@sustainablelists.org
http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org
Biofuel at Journey to Forever:
http://journeytoforever.org/biofuel.html
Search the combined Biofuel and Biofuels-biz list archives (50,000 messages):
http://www.mail-archive.com/biofuel@sustainablelists.org/
