Scenario - Removal of lead based paint (LBP) from iron and steel bridges, dating from separate decades in the second half of the 19th century. Any views on % lead in paint sufficiently small as to enable conclusion that occupational exposure during removal of LBP would not be significant within the meaning of CLAW 2002, i.e. less than 50% of OEL and no substantial risk of ingestion. While realising that non-occupational exposure of children in homes not a good indicator of occupational exposure for various reasons..... WHO (1977) Environmental Health Criteria 003 - Lead identifies two 1973 which both found that the vast majority of small children with substantially elevated blood lead levels lived in homes with at least one surface where lead in paint >1% Legislation enforced by US Housing and Urban Development defines LBP and "paint or other surface coatings that contain lead in excess of 1.0 milligram per centimeter squared or 0.5% by weight" However HUD also defines Lead-free paint as having no more than 0.06% by weight. We’ve taken off the paint from a number of structures with half having lead in paint levels between 0.06 and 0.5%, and the other half having a lot more than 0.5%. Given that these structures have had very little maintenance in over 100 years, the variance in % levels for each decade is somewhat surprising. There are numerous similar structures that can still be assumed to have LBP – and whilst each will need to have paint tested before removal, I’m trying to think through what to put into CDM health and safety file…….. HSE guidance indicates that exposure levels during paint removal from similar structures can vary widely (even on the same job0 but I can’t find any authoritative UK or European guidelines as to when the % of lead is so low that one could reasonably assume that exposure would not be significant. I am also aware that when HSE were taking a very close interest in the refurbishment of the Hielanman’s Umbrella at Glasgow Central station (so that one could expect better than average compliance) ended up with workers being suspended from work with lead.

Always a difficult question as air monitoring in open locations is next to impossible to get accurate. I really would look at effective PPE and welfare facilities. I have found the residues to be the biggest problem under UK law. Bob

I'm not sure what stage of the project you are from the description, but if at the planning stages I can't see from the details you've got, that you can say whether the exposure will be significant or not. I would assume you'd have to take the worst case & assume significant exposure with the relevant requirements from CLAW - blood testing, face fit tested masks, HEPA filters etc, etc. I would imagine the easiest way to assess exposure is to do some occupational hygiene testing when the jobs underway.

Thanks for all the responses to date. Project is complete - environmental issues dealt with within sheeted scaffolds. We're now putting together the CDM Health and Safety File for the next 100 years - during which time paint will be removed from other bridges.