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