Lead and Explosives in Construction
How lead exposure is monitored and controlled in construction, and how explosives are transported, stored, initiated and fired, with the rules on misfires.
Pages in this chapter (1 of 2)
10.1 Lead Safety on Construction Sites
Lead is a very toxic substance. People exposed to lead or lead compounds may become ill or even die of lead poisoning. The body removes lead slowly, so breathing even small doses over a long time can cause lead poisoning. Workers at or near contaminated sites are at greater risk.
| Term | Meaning |
|---|---|
| Action level | 30 micrograms of lead per cubic metre of air (30 µg/m³), averaged over eight hours. At or above it, exposure must be monitored closely so that the PEL is not approached. |
| Permissible exposure limit (PEL) | 50 µg/m³ averaged over eight hours. |
| Toxic substance | A substance that changes how an organism works through a chemical process. |
Why lead is used in construction
Lead has a low melting point, high density, is easy to shape and is widely available. It is found in paint primers on steel and iron, in alloys, in lead shielding in walls and in lead pipes. Construction workers face greater exposure and continuing exposure without controls can be catastrophic.
Health effects
Lead can severely damage the nervous, urinary, blood forming and reproductive systems. It causes anaemia by hindering the formation of haemoglobin, damages kidney cells and may lead to kidney failure, and lowers sperm count and fertility in men. Lead in a pregnant woman can cross the placenta to the child.
Activities that cause exposure
Removing lead based paint, melting and casting lead and babbitt metal, torch soldering, reclaiming lead acid batteries, grinding or sanding lead containing materials, machining lead and cutting lead containing materials with a torch.
Monitoring
- If the first assessment shows exposure below the action level, the employer does not need to assess again unless processes or controls change.
- If exposure is at or above the action level and at or below the PEL, monitoring is done at least every six months, and continues until two consecutive measurements taken at least seven days apart are below the action level.
- If exposure is above the PEL, monitoring is done every three months. When two consecutive measurements taken at least seven days apart are at or below the PEL but at or above the action level, monitoring continues every six months.
Control measures
The employer must make sure that lead controls and good work practices keep exposure at or below the PEL: exhaust ventilation with HEPA filtered equipment, encapsulation of lead paint, substitution of other materials, process changes such as brush or roller application instead of spraying, and isolation of the work. Part 10 of the general industry book describes each of these.
Hygiene
- Provide adequate washing facilities so that workers do not carry contamination into clean areas.
- Provide clean changing areas, and eating areas that are separate from the work area and not contaminated.
- At the end of the shift, put disposable clothing and shoe covers in sealed, impermeable lead waste containers. Put contaminated clothes, shoes and PPE in a closed container for professional laundering. Shower, wash hair and skin and change into street clothes.
A study aid, not published or endorsed by IOSH or OSHA. Laws and limits differ between countries.