Re: Paraformaldehyde

From: T. E. Andersen ^lt;postlister@microscopica.com>
Date: 03/18/04-04:43:46 AM Z
Message-id: <40597D62.6080704@microscopica.com>

Jack Fulton wrote:
> A question to Ryuji &Tom . . . I've had a near gallon of Formalin (37%
> formaldehyde) in a plastic bottle, sitting in my darkroom, for a couple
> of decades. I've kept it from my days of working in the Agfa color
> process in the 60's and 70's before it was taken from the market.
>
> Do you think my Formalin is still good? Has is perhaps become
> depolymerized or somehow 'turned' and therefore not usable?
>
> I have retained it to use only now and then as a hardening agent.
>
> Thanks
> Jack Fulton
>

Hi Jack,

If your bottle is that old, you may find that there is a white
precipitate in the solution. If that has happened, there is really no
way of telling how much formaldehyde is still left in the solution (the
white stuff is a polymer of formaldehyde). If the solution is still
clear, I see no reason why you should not be able to use it for
alt-photo (I would not use it for scientific purposes, but still...).

Best regards,

Tom Einar
Received on Thu Mar 18 04:41:39 2004

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