Is it likely that there is lead in the varnish of my old 1930's hardwood floor?

Question

I have recently uncovered an old (and presumably original circa 1930) hardwood floor in the hallway of my house. Over the past couple of weeks I have been cleaning and sanding it in order to re-varnish (or most likely wax) it.

I have not been taking any special precautions about when sanding the floor, over and above using a face mask, gloves. It was my understanding that old paint used to have lead in it, but that old varnish didn't. Is this the case?

Is it likely that there is lead in the varnish of my old 1930's hardwood floor?

Answer 1

This page from Stanford University states:

Presume all paints and varnishes applied before 1980 contain lead including finishes on old toys, furniture and playground equipment.

Therefore you should take precautions when removing the old material.

However, most of the risk from lead is due to the long term exposure to the paint, so the precautions you have been taking should be adequate.

Answer 2

Clear varnish does not contain pigments, and so it won't have any lead-based dyes. However, additives called "drying agents" are used in oil-based coatings such as varnish to accelerate the polymerization of the oil. One such agent that has historically been used is lead acetate. Lead compounds have been used for oil drying as far back as the 1800's, through to 1970-something, and for centuries it has been known by artists that paint with lead-based pigments dries faster than the base without pigments. Here is a paper that gives moreinformation as well as historic notes about oil drying agents: http://www.si.edu/mci/downloads/articles/tusoma_paper.pdf

Answer 3

Home Depot and the like sell lead testing kits very cheaply (e.g. $10). You'll want to take a utility knife and cut through and expose all the layers down to the bare wood to test. That's the only way to answer. Mikes's advice is very good. Don't take any chances with kids and pregnant women.

Answer 4

My understanding is that the varnish or shellac did not contain lead. How ever some of the stains that were used did contain lead. Also any sanding that was done during the original painting. That said you can buy a home test kit but you will only be getting a small sample. I would say to treat it as if it has lead. Keep small children and pregnant woomen out of the work area. Isolate the rest of the house from the work area. Get a HEPA bag for your shop vac (available at the big box stores) to contain the dust. Clean the area everyday to avoid tracking it through the house. Clean with a damp rag to get a much dust as possible. When the ssanding is finished clean the entire area,walls, ceilings, doors, windows etc. The dust will go everywhere.