aluminium dirtying hands

[fred]

A garden pick up tool I have is made from Al. tube. Of late it has started to leave my hands black. I suppose the anodising has failed? Any easy solution ?

[R D S]

I have hand tools that do the same, I wonder if it's harmful?

[GB]

Wrap it in gaffer tape. :)

[Fredxx]

There are exposure limits for aluminium powder in air but not aware of any health issues regarding skin contact, suggesting there isn't a known issue.

The closest I got was this article:

for the first instance of skin, "Aluminium penetration of the skin is very shallow" though I assume they must mean the oxide.

A general rule is that you should limit exposure to a chemical so perhaps if there is any concern then wear gloves. Probably not a bad thing to do in any case.

[polygonum_on_google]

Slap on a bit of lacquer/varnish/similar?

On the pick up tool not your hands.

[Tim Lamb]

In message <Q9OdnXHMN [e-mail]>, Jimk [e-mail] writes

They clean up well if you cook anything involving Vinegar:-)

[The Natural Philosopher]

Not really. "Aluminium oxide is a common ingredient in sunscreen and is sometimes also present in cosmetics such as blush, lipstick, and nail polish." (wiki)

There you go, cheap sunscreen on your hands

[The Natural Philosopher]

And that was the issue. clearly aluminium oxalate was being produced and ingested.

The question was if that was a Good Thing. To be on the safe side aluminum saucepans were phased out

[Chris Hogg]

Hmm...yebbut, why is it black on Fred's hands. I have a related experience - the telescopic ladder into my loft is aluminium, and where the sections slide over each other, it rubs off black. Pure Al2O3 is white. Perhaps in both cases they're an aluminium alloy, duralumin or whatever, with other metals in there that interact with the oxidised aluminium to absorb light across the visible spectrum, like many metal ores (pure tin oxide is white, but cassiterite, as the oxide ore, is black due to impurities).

[Andrew]

Don't cook rhubarb in aluminium pots. Also cleans them up

[Andrew]

An awful lot of aluminium must have been ingested by huge numbers of people over the decades before they did.

[Chris Hogg]

People of Camelford in North Cornwall know a bit about it. Gets into the brain.

[newshound]

If you look at sites where there is fretting between aluminium parts, they are usually black (and the debris that comes off on your hands leaves black marks like graphite or laser toner). Fretting debris is very finely divided, on steel it looks like cocoa (even though it is normally Fe2O3 which is a mid-brown in its bulk state).

Aluminium fretting debris will be predominantly alumina. While pure alumina is white as a micron sized powder, I suspect that it absorbs light better when more finely divided than that (as fretting debris is likely to be). My loft ladder has some dark contact sites but the main rubbing regions are bright and shiny (i.e. covered with a very thin continuous alumina film).

I think the answer to the garden tool might be a regular wipe with a greasy rag, or perhaps application of a wax polish (I was interested to see them do that on a seaman's knife in repair shop earlier).

I agree that there is little risk of toxicity.

[newshound]

Although that was because it went into the drinking water in a soluble, ionic form.

[tabbypurr]

friction tape, bike handlebar rubber sleeve, paint, gloves.

NT

[Andy Burns]

[Brian Gaff (Sofa]

Not really, the oxide will erode and effectively leave ally oxide on your hands. Are you sure it was anodised? Most ones I've seen seem to be a kind of coating that feels smooth, or are covered by that stuff you get on tennis racket handles with heat shrink at either end of it.

Brian

[Brian Gaff (Sofa]

Only if you lick it , I'd imagine. I used to get it all the time when I made my own vhf aerials. I'm still here. Brian

[Jimk]

Was the ali saucepan poison theory debunked?