May 2001 Volume 23 Number 2
Last issue I wrote a short (and admittedly weak) column about dealing with hidden dangers of exposure in conservation. My basic advice, interspersed with song lyrics, was HEPA, HEPA, HEPA.
I mentioned how I found flakes from a tacking margin of a 1945 painting to be lead based and how these tiny flakes were dislodged in a treatment. Most importantly, by the simple act of cleaning up afterwards with a HEPA filtered vacuum, any potential exposure was eliminated. By extension, any time one is cleaning out a frame rabbet, a HEPA vacuum should be used.
Here are a couple of more harrowing stories about what you can't see hurting you. And again, the good news is that proper hygiene and a HEPA vacuum, judiciously applied, should save the day.
The May issue of ACTS Facts, which I plug almost every column, includes an article "Lead Poisoning from Restoring Stripped Furniture."
In an initiative to combat lead poisoning in children, the State of California, as well as some other states, tests all children for elevated blood lead levels (BLL). The rationale is that lead poisoning in children effects mental development and, if unchecked and untreated, will leave a child intellectually disadvantaged for the rest of their lives. It's a great program and well worth the tears associated with a blood sample from baby. In 1998, the 18-month-old child of a worker at a furniture refinishing company tested positive for lead poisoning (26 µg/dL). Other family members were tested. The father tested at 46 µg/dL and a 4 month old daughter had a BLL of 24 µg/dL.
Investigators investigated. They found that the furniture "repairing and restoring" company had the furniture chemically stripped before it arrived at the shop. Even though seemingly cleared of lead based paint, there was sufficient residue to be dangerous. The use of alkaline stripping was found to cause the lead to migrate from the paint layer into the pores of the wood. Working the stripped wood with saws and planers inside the shop and hand and power sanding in an outside area released the lead that had penetrated into the surface of the wood.
The workers did not wear any protective clothing. Lead in the wood dust was carried home on their clothes and shoes and in some cases contaminated their families.
Admittedly, conservators don't work wood surfaces this extensively. Nor do we use alkaline based strippers. However, we don't always know the previous treatment history of a work either.
The real moral of this story is: if we are in the habit of wearing the correct personal protective equipment (PPE) and clean-up afterwards when we perform tasks that are potentially dangerous, we can protect ourselves.
If we assume wood surfaces could be contaminated and therefore, when sanding or machining them, we should wear a lab coat, a respirator if generating airborne dust, and clean-up afterwards with a HEPA vacuum. No big deal really. Just common sense. And, don't forget to vacuum your shoes.
And one last thought on the subject. If you work with any materials that could pose a lead hazard (paintings or objects come to mind) when you get a physical exam, ask you doctor to add BLL (blood lead level) and ZPP (zinc protoporphyrin) tests to your normal blood work-up panel. Making the front page of the Los Angeles Times (on Friday, April 13th, no less) was a horrifying story about CCA treated wood. CCA is chromated copper arsenate, a wood preservative. It's as nasty as it sounds, and the wood industry has worked hard at not explaining safe usage of the wood to consumers. For the last 25 or so years, lumber intended for exterior applications has often been pressure treated with CCA to protect it from termites and fungi.
And again, I mention the issue not just for those of you who are planning to add that deck to your dream home, but also for conservators working with contemporary materials. Any work incorporating wood made in the last 25 years could have been treated with CCA. Particularly if it was ever intended for an outdoor environment.
And just how do we protect ourselves? The EPA is recommending:
And what do I recommend? Protective clothing and HEPA vac. And most importantly, the understanding that conservation can be something like Candid Camera. When you least expect it, smile, you can be exposed to toxins.
Making the conservation studio a safe place can be a daunting task. And remember, from the government's point of view,we are a laboratory. So, in an effort to make making a safe conservation laboratory a reality, the WAAC board has decided to mail all 2001 WAAC members a copy of Safety in Academic Chemistry Laboratories, published by the American Chemical Society.
This is the 6th edition, published in 1995, and it is a wonderful resource. It's 77 pages long, but relax, many of the pages don't apply to us. (Most conservation labs don't need a policy on "insertion of glass rods into stoppers"). The pages that do apply basically describe a Lab Safety Plan. When it arrives, give it a look.
So, what's the moral of this column? HEPA, HEPA, HEPA, wear gloves and a lab coat when doing dirty work. Our working assumption should be that everything we work on could be contaminated and therefore hazardous BUT, if we are sensible we can avoid contaminating ourselves, or colleagues and families.
Timestamp: Thursday, 11-Dec-2008 13:02:36 PST
Retrieved: Wednesday, 21-Feb-2018 01:14:56 GMT