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Publication: November 2005. For information about changes, please see the
Revision History.
Chapter 20: Lead Safety
Overview
Lead is a heavy-metal element well known to be hazardous to both human health and the environment.
This chapter sets forth requirements for protecting workers from lead. Chapters 40, "Hazardous Materials", and 17, "Hazardous Waste", cover the use and disposal of it.
Hazards/Impacts
The presence of lead in human blood can cause damage to and reduce the number of red blood cells, leading to a condition known as anemia. Lead also interferes with the transmission of nerve impulses, resulting in damage to hearing, thinking, sense of touch, and muscle control. Our bodies store lead in the bones as if it were calcium, and it is therefore eliminated very slowly, with a biologic half-life estimated between 10 to 20 years. Because excretion is slow, accumulation in the body occurs readily.
Lead also reacts with oxygen to produce lead oxides. While pure lead is a heavy and solid material, lead oxides are powdery and easily released into the environment. Lead oxide dust from lead shielding and contaminated pallets or surfaces can be harmful to humans even with a short exposure.
Exposure Sources
Lead is present at SLAC chiefly in three forms:
- Radiation shielding
The most likely source of lead exposure at SLAC is through the handling of lead for radiation shielding. Rough handling of the lead shielding can cause surface dust to be released into the air.
- Radiation shielding filler
When shielding blocks are moved, legacy lead (see Section Error! Reference source not found., "Error! Reference source not found.") from oxidized lead shot or matting can crumble into smaller fragments, leading to the potential release of lead dust, which can then be accidentally inhaled or digested.
- Paint
Some buildings at SLAC have exterior and interior paint that contain lead. Any grinding, sanding, wire brushing, or other forms of abrasion of this lead-containing paint can generate lead dust.
Scope
This chapter applies to all personnel who work with materials containing lead. Typical lead work includes handling lead bricks, sheets, or plates in radiation shielding. Other activities in which lead or lead dust may be encountered include cutting, drilling, machining, melting, and soldering of lead-containing materials. Remodeling or demolition work may necessitate the removal of lead-based paint.
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