[IainThomson]

I'm an Electrical Engineer designing the system in a large lab complex. Some of the rooms will be using Formaldehyde in fume cupboards. Does Formaldehyde react with any metals to cause corrosion? In particular will it react in any way with copper from cables/light fittings or aluminium? Same question applies to the fume hood itself, can it cause any corrosion there?

This might seem like a silly question but my chemistry knowledge is almost nonexistent.

[IainThomson]

I guess I should also had PVC and Crosslinked polyurethane to this. While I highly doubt it, better to check so the insulation doesnt get worn away at an accelerated rate.

[IainThomson]

Totally forgot about this until now, I still need an answer. I kind of put it on the back burner for a while

[Arkcon]

I don't know, but there are probably legal specifications, somewhere, outlining the standards to which your construction should meet. 

Just because they said they'll use formaldehyde often, doesn't mean they won't use something worse, at least once in a while. 

On the other hand, if I were to use a reagent called perchloric acid, in a hood that was not designed for it specifically, it could be quite hazardous, but that would be all my fault, not the designers.  So ... catch-22.

I always had the image in my mind that lab hoods were large factory manufactured built-in appliances, not something designed by a building's engineer.  Am I totally off base?  Do you often design custom lab hoods?

[IainThomson]

The hoods question was more of an after thought, main concern is the exposed plug terminals and any exposed copper/alu on light fittings. I'd kind of assume fume hoods will be designed to be fit for purpose.

[Arkcon]

OK, commercial fume hoods, with parts by you, specifically, light fixtures and outlets.  Either those are included in the "fume hood package", or the fume hood manufacturer has some specifications for you.  Basically, how you should shield your attachments, what quality they are to be made of, etc.

FWIW, formaldehyde is a common mild reducing agent, so I don't expect it will corrode aluminum or copper, in fact it will do the reverse.  The PVC power cord insulation, that I don't know for sure, it really depends on formaldehyde strength, duration of exposure, and frequency of exposure.

All fume hood will have to be validated for functionality, prior to use, and at least annually (or more often) thereafter.  A certified validator, should notice something horribly unsafe, and let you know, or not as the case might be.  Regular checks, for exposed damage to attachments, are the responsibility of everyone -- from fume hood validators, facility maintenance, to individual users.

[Borek]

formaldehyde is a common mild reducing agent, so I don't expect it will corrode aluminum or copper, in fact it will do the reverse.

Sounds logical, although once it gets oxidized it goes acidic - aluminum may not like that.

Could be we are both off

Manufacturer specifications seems the best place to check the reality.

[Arkcon]

Sounds logical, although once it gets oxidized it goes acidic - aluminum may not like that.

Uhh...opps again on my part.  Logically, if the formaldehyde is used as a reducing agent, then it ends up oxidized -- to formic acid.  Yeah, that's a little harsh on aluminum.  But that ties in to what I originally said, they might end up using any reagent in the fume hood, when they least expect it, even though they should know better.

Manufacturer specifications seems the best place to check the reality.

That's what leaves me wondering.  Everything we use is inside of a building.  If the equipment is rated for something, but the building isn't...but how often does that happen?  You've gotta see what the manufacturer says.

It's typical for hoods I've worked in, after years of use before my arrival, to have somewhat corroded switch plates, or green corroded taps for water, for example.  I've never considered, "What shape are the wires behind all this?"  Perhaps I should have, or perhaps there is an enforced quarterly review of hood components -- they at least need a regular vacuuming, to remove dust, maybe they're checked then?"  You should check with maintenance people, maybe they have standards.

Again, FWIW, the only time I've heard of damage to electrical insulation was a technical note from Waters.  It appears there was a previously unknown hazard associated with their equipment.  Basically, if you let the power cord sit in a puddle of THF, you can remove enough of the insulation, to expose bare copper wire, that then poses a hazard if you expose it to a conductive solution.  Of course, there's about a half a dozen reasons why an chemist should never let that sequence of events  happen, but ... there you go.

Okay, long story short (too late?)
1). Systems may be more robust then we give them credit for.  Manufacturers and regulatory bodies have those answers, not lab chemists

2).  Chemists and maintenance people have a responsibility to monitor and control the lab's equipment, all the way back to the girders, if need be.  Again, there are probably rules, from point 1, that facilitate that.