Re: Paraformaldehyde

Robkin, Eugene wrote:

> Paraformaldehyde used to be readily available at supply stores for
> recreational vehicles and trailers. It is used to sanitize septic waste
> storage tanks. I haven't looked recently to see if it is still on the
> shelves or if it has been replaced by something else.
>
That should do wonders for the natural bacterial community doing us the
favor of degrading the waste. It's a very strange world we live in!

> How is it depolymerized. From some of the discussion it appears that
> all it takes is an acid environment. Is there a path that leads
> directly from the paraformaldehyde to a formalin solution of useful
> concentration? Denatured alcohol is very easy to find but again I
> haven't looked for methanol by itself.

You need to mix the powder with distilled water, and heat the mixture to
about 70*C. Then add enough base (usually 1M NaOH, drop by drop) to make
it depolymerize. You'd normally make a solution in the 10-25%
(weight/volume) interval. It really requires a fume hood, as hot
formaldehyde is a lot nastier than cold (more formaldehyde evaporates).
A pure formaldehyde solution will turn acid, and eventually repolymerize
to some extent. I have never tried stabilizing the solution with
methanol. If you want to do that, why not just use the commercial
formalin? Surely, it can't be used to make drugs???? But then again, my
experience in making drugs is zero :-). The only alt-photo
situation I can think of, where using paraformaldehyde would be in its
place is if you have to transport the nasties. Paraformaldehyde is
relatively safe as long as it is dry (please note that if you inhale it,
it is no longer dry!), and will probably even be allowed in the
checked-in luggage on a plane. The situation in the US may be different,
though, since that terrible 9-11, anthrax and all. Best check first!

>
> I think this would be useful information.
>
> As far as lab safety is concerned, I was taught four primary rules.
>
> 1. Protect your eyes. 2. Protect your eyes. 3. Protect your eyes.
> 4. Protect everything else.
>
> E. Robkin

Sounds like good safety rules, as long as you make sure you include #4!

Best regards,

Tom Einar Andersen
Received on Wed Mar 17 18:23:56 2004