Re: [PPLetterpress] Re: health question - fuzzy whitish-grey powdery stuff on old lead alloy type
- Thank you so much for a very informative message.
>From: Steve Robison <robisonsteve@...>
>Sent: Oct 16, 2007 2:16 PM
>Subject: Re: [PPLetterpress] Re: health question - fuzzy whitish-grey powdery stuff on old lead alloy type
>(I will be cross posting this on various yahoogroups
>such as sfletterpress and ppletterpress lists, etc.
>because I think the topic is worthy of discussion for
>every letterpress printer...I hope no one gets too
>upset about that...I just think it falls into the
>realm o health and safety and deserves to be shared by
>As mentioned in earlier recent ppletterpress posts,
>the fuzzy whitish-grey powdery stuff on old type is
>mostly lead carbonate (PbCO3 - aka: "white lead") and
>is very toxic if ingested. The hydrochloric acid in
>the human stomach breaks down the PbCO3 and releases
>the lead into the bloodstream. Once there it is free
>to travel through the body.
>Toxic amounts of lead in the bloodstream may cause
>irreversible neurological damage as well as renal
>disease, cardiovascular effects, and reproductive
>toxicity. As a neurotoxin in the brain, particularly
>in young children, it can be the cause of a whole
>range of problems with the interruption of
>neurotransmitter function and overall brain function
>and can, if not counteracted, cause permanent brain
>So yeah, this stuff is not to be take lightly. But
>before I scare you so much that you give up lead alloy
>type altogether, I want you to know that it can also
>be handled in ways that substantially mitigate against
>these risks. So don't freak out completely about this.
>Just handle it with knowledge and some common sense.
>Here are the main ways it can cause problems and some
>common sense steps to deal with it without getting all
>unnecessarily paranoid about it...
>1. Don't eat it! (Lead carbonate and other lead salts
>that may accompany it are actually said to be sweet to
>the taste, so very young children who are putting
>anything and everything into their mouths tend to be
>the most vulnerable...but why would any adult do this
>except to compete in the Darwin awards???!!!)
>2. After handling type (fuzzy or not) wash your hands
>before eating or putting your fingers in your mouth.
>We learned this in kindergarten to reduce the spread
>of viruses and bacteria, but it's also a good practice
>throughout adult life too, especially if you're a
>letterpress printer and want to have a lead-free life!
>3. If there is a lot of the lead carbonate dust left
>in a type case, don't blow on it or otherwise stir it
>up and breathe it...because the dust will collect in
>the mucous membranes of your airways and mouth and you
>will eventually wind up swallowing some of it... and
>once swallowed it is in your stomach and eventually
>into your bloodstream.
>OK. Here's what I do when I obtain used type to reduce
>and practically eliminate all of these risks...
>I like to carefully take all of the type out of the
>case that I receive it in, and then, using rubber
>gloves, soak and gently bathe and brush the type in a
>bathe of mineral spirits (paint thinner)using an old
>toothbrush to remove most of any residual lead
>carbonate dust and other debris. Remember to only
>brush the type when it's thoroughly submerged or at
>least covered with wet solvent so that none of the dry
>lead carbonate can fly into the air.
>Some people have also suggested using vinegar (mild
>acetic acid) to remove the lead carbonate. This
>certainly works...just remember to wash the type
>afterward with lots of clear running water to remove
>any residual acetic acid, or in some way neutralize
>any remaining acetic acid before returning the type to
>the case (maybe with a mild baking soda solution
>followed by a water rinse???). Otherwise the presence
>of residual acid on the type will actually accelerate
>the formation of more new lead carbonate after you
>have just gone to great lengths to removed it!).
>I then carefully vacuum the type case using my shop
>vac and avoid breathing any dust. Wearing a dust mask
>during this process would probably be a good idea too,
>although I confess that I have never done so. I just
>make sure the vacuum is sucking up the dust so that
>it's not getting kicked up in the air. I then take a
>rag dampened with water(lightly squeezed out so that
>it's just damp and not dripping wet) and slowly and
>carefully wipe the compartments of the case to remove
>any residual dust that might contain any possible lead
>carbonate. I let the case dry thoroughly, then re-lay
>the case with the clean type into the clean
>As I mentioned in earlier posts, if you continue to
>clean your type after each use on the press with a
>mild solvent like kerosene or mineral spirits, you
>will coat the type with a mild residual film which
>will help prevent any further corrosion.
>So now that the type and case are cleaned, what do you
>do with the lead carbonate that you've removed??
>Well, if you have followed the process above, the lead
>carbonate will be in solution with the solvent or with
>the vinegar that you used to clean the type, or in
>your shop vac after vacuuming the cases, or in the
>water that you used to rinse the vinegar off the type,
>or on the damp rag that you used to wipe out the
>cases...and then what do you do with it??
>That's a tough question, because in most cases there
>is very little lead carbonate present in the first
>place and you can barely see it on most of the used
>type you obtain In other instances, where it is
>clearly visible on the type, it is difficult to see it
>when it is removed and in a liquid solution. So my
>admonishment is to just do your best to keep as much
>of it as possible from getting airborne and by keeping
>as much of it as possible out of the landfill. Do this
>by containing it in plastic bags, jars, etc....and
>taking it to your nearest toxic waste disposal site
>when you need to...along with batteries and other
>items containing toxic metals. They may look at you a
>little funny, but hey, they have ways of dealing with
>it that you don't. Just clearly label it (Lead
>carbonate in vinegar/Lead carbonate in water, etc.)
>and hand it over.
>Or, if you just can't get a grip on all of this, there
>is always photopolymer!
>Does this help?
>Belmont, CA (about 25 miles south of San Francisco)
>Need a vacation? Get great deals
>to amazing places on Yahoo! Travel.
>Yahoo! Groups Links