Wiring Could Pose Lead Risk

As early childhood educators, we are all aware of the risk of lead base paint in older buildings and how lead poisoning can impair children's development. There is growing evidence that data cabling in US buildings can pose a toxic hazard of lead dust accumulation in ceilings and floors.

Stabilizers are added to certain plastics during their manufacture to increase resistance to heat, sunlight, moisture and other stresses. PVC is particularly prone to heat degradation which leads to wire insulation cracking or otherwise failing. Most cable is covered with PVC that is heat-stabilized with lead. In the past, lead was as much as 10% of the total weight of the insulation. In newly manufactured wire, the lead is 2-5% of the insulation by weight.

Old cables that are not in conduit can pose a risk when they are removed. As insulation ages, the lead migrates to the surface. So when the cables are removed it leaves behind lead particles loose in the space above the ceiling, and it can easily reach the building's occupants. Or if it is in the outdoor play space, it can contaminate the soil.

To keep lead dust out of a building's air circulation, the best practice is to specify lead-free wiring that does not contain lead stabilizers. If cable that is stabilized with lead is used, it should be installed in metal conduit and not directly exposed to the conditioned air circulating through the ceiling.