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.=A0 Hydrogen peroxide can react with carbonyl compounds to form some very explosive compounds, thus the restrictions on liquids carried on airplanes.=A0 I would be cautious, even though paraformaldehyde is a likely explanation.=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.

Ben

Colleagues,

I wondered if you’ve run into this previously:

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

The bottle is the original Mallinckrodt AR bottle.

It’s about =BE full, and appears to have been opened.

About 50% of the volume of the bottle is a white precipitate, with about =BC volume 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