Lead wipe sampling
We recently conducted some tabletop lead wipe sampling and got some results slightly above 10 µg per square foot. Are there corrective action recommendations other than better house cleaning to bring the levels down?
Comments (5)
That’s actually pretty low.
What do you do with lead? Solder? Use your hierarchy of controls.
Restrict unnecessary access until you get the levels down (and even do it afterwards, too). Make sure you're preventing cross-contamination to other areas.
What kind of operation you got? Where did the lead come from?
I got a couple lead horror stories! It can be a bit___!
The one thing I did learn is that it is a heavy element, so it cannot stay in air very long. It is very difficult to inhale it, which is the fastest way for anything to get into the human body. It also hard to absorb through the skin unless there is a break in the skin. That is why gloves that are impervious to liquids should be used. That leaves ingestion. So people must wash their hands and practice good hygiene after working in lead to ensure while eating or drinking we don't ingest it! In my corporate job we cut a lot of steel bar stock, some steels, including the ones we used have a heavy lead content. For some reason lead does not accumulate in water based metal cutting coolants used in most CNCs. However, it does accumulate in solvent (oil) based coolants used in Screw Machines. Naturally, we recirculated the coolants over and over and over........ So in our Screw Machines we had to teach employees about Lead and proper personal hygiene as it would build up to high concentrations. Machinists all have a problem with wearing gloves as they say they lose their "Machinist Touch".
For reference, the EPA HUD clearance level for lead on floors is 10 ug per square foot. This means, according to the EPA, 10 ug per square foot is safe for babies to crawl around on. Up until 2017 the clearance level was 25 ug per square foot. The clearance level for window sills is 100 ug per square foot down from 250 prior to 2017. I'm saying this not because I think you should do nothing, but just to illustrate that even if you're quite a bit above 10 ug per square foot, it's not an emergency and 6 years ago the EPA would have said that's fine for a daycare.
As far as what you can do, look at your hierarchy of controls. Can you use a lead free solder? Or maybe one with a lower lead content? Would you process allow for a local exhaust ventilation system? Maybe a cross draft or down draft table? If not, could you wet wipe the table in between jobs or batches?