Thoughts:

I do not wish to seem like an alarmist, but on page 82 of The Chemistry of the Carbonyl Group Vol. 2 , there is an equation showing formaldehyde reacting with oxygen to give carbon monoxide and hydrogen peroxide.=C2=A0 Hydrogen peroxide can react with carbon yl compounds to form some very explosive compounds, thus the restrictions on liquids carri ed on airplanes.=C2=A0 I would be cautious, even though paraformaldehyde is a li kely explanation.=C2=A0 A lot can happen in 35 years.

Perhaps a small sample could be mixed with ferrous ammonium sulfate solution, just to check, at least as a first step.< /font>

Ben

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From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**LIST.UVM.EDU] On Behalf Of Dan Blunk
Sent: Wednesday, August 11, 20 10 1:28 PM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: [DCHAS-L] Old Formalin With Lots of Precipitate

Colleagues,

I wondered if you’ve run into this previously:

A physical plant person brought me a pint reagent bottle labeled 37% Formaldehy de this morning that he found while remodeling a workspace.

The bottle is the original Mallinckr odt AR bottle.< /font>

It’s about =C2=BE full, and appears to have been opened.< /p>

About 50% of the volume of the bottle is a white precipitate, with about =C2=BC vol ume of clear liquid above.

The purchase date on the label is smudged, but it appears the bottle is at least 35 years old.

As I remember, aldehydes do undergo a slow polymerization reaction. I wouldn’ ;t expect an aqueous solution to form peroxides.

Thoughts?

 

Dan