Lead Paint and Access at a Coastal School
A two-storey residential school building in a coastal district needs external repainting before monsoon. The wall is 7.2 m high, and the existing coating is chalky, with several cracked and flaking patches. The site supervisor proposes dry-scraping the old paint from bamboo ladders tied with coir rope, then applying a solvent-based primer. The building is occupied, and children use the courtyard below. On the first day, a worker becomes dizzy while priming a closed stairwell; another continues scraping without a respirator. The paint is from before 1990, so lead content is unknown. Wind is gusting to 35 km/h, and rain is expected within 48 hours. The contractor has two extension ladders, one mobile scaffold frame without guardrails, and no lead test kit. The client wants the front elevation finished in three days. The workers ask whether they can continue after tying a tarpaulin to the scaffold.
1. Identify the principal safety hazards and decide whether work should continue. Set out the control measures in order of priority.
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Work should stop until the access, lead, solvent and weather risks are controlled. The main hazards are: falls from height from ladders and an unguarded mobile scaffold; lead-bearing dust from dry scraping an old coating of unknown composition; solvent vapour in a closed stairwell; wind loading on a tarpaulin; electrocution risk from cords and wet conditions; and public exposure because children use the courtyard.
Priority should follow the hierarchy of control. Eliminate/substitute: do not dry-scrape unknown old paint; test for lead and use wet methods or a chemical stripper; choose a water-based primer where the specification allows. Engineering: erect a proper scaffold with guardrails, toe boards and stable footing; use ladders only for access, not as a working platform; provide forced ventilation in the stairwell; isolate the courtyard with barriers and a drop zone. Administrative: lead test before disturbance; exclusion zone; trained banksman; stop-work rule for high wind or rain; emergency plan for solvent exposure. PPE: fit-tested respiratory protection, eye protection, gloves and coveralls for the task, but PPE is the last line and does not make dry scraping acceptable. The tarpaulin should not be tied to an unguarded scaffold in gusting wind; it adds wind load and can turn the scaffold into a sail.
2. A later test shows 0.8% lead in the old coating. What changes in method, PPE and site control?
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At 0.8% lead the coating must be treated as lead-containing. Dry scraping, dry sanding and power tools that make fine dust should be prohibited. The method should use wet scraping or a proprietary chemical stripper, with loose residue collected on disposable polythene sheets. The work area must be sealed from the school, and no eating, drinking or smoking should be allowed in the zone.
PPE should include a fit-tested particulate respirator suitable for lead dust, disposable coveralls with a hood, nitrile or appropriate gloves, and eye protection. Workers should wash hands and face before breaks and change out of contaminated clothing before leaving. Waste, dust, used sheets and filters must be bagged, labelled and disposed of as lead-contaminated waste, not swept into the courtyard or mixed with ordinary rubbish. Blood-lead monitoring may be advisable for repeated exposure. The client should be told that the three-day deadline is unrealistic if lead controls are required; trying to meet it by dry scraping would create an unacceptable exposure to children and workers.