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Silica Dust & the Cutting of Roof Tiles . Marjory Mitchell HM Health and Safety Inspector (Occupational Hygiene) Duncan Smith HM Health and Safety Inspector (Occupational Hygiene). How did we get here?. Construction Supply Chain Projects kerb, paving and block cutting
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Silica Dust & the Cutting of Roof Tiles Marjory Mitchell HM Health and Safety Inspector (Occupational Hygiene) Duncan Smith HM Health and Safety Inspector (Occupational Hygiene)
How did we get here? • Construction Supply Chain Projects • kerb, paving and block cutting • Led to numerous queries about dust suppression in relation to roof tile cutting • Construction industry engagement on issue and solution: • Improve knowledge of health risks • Improve use of controls
What is the problem? Dust in general and Silica in particular Silica is one of the most abundant materials on earth Found in many materials used in construction: • Sandstone (>70%) • Brick and tiles (up to 30%) • Cement, mortar, concrete (25 to 70%) • Sand, gravel, flint (up to 70%)
Poor industry appreciation “It’s only dust you know!” Industry appreciation of the risk is poor: • People not aware of health risks • Underestimation of exposure levels • Require convincing that control measures work
Why is it a problem? Main concerns are: • Silicosis • Lung Cancer • Chronic lung diseases, emphysema, bronchitis, COPD. These diseases; • Cause reduced lung function • Continue to develop after exposure stops • Can cause death
Why is silica a problem? • Issue is Respirable Crystalline Silica or RCS • Respirable particles can penetrate to deep lung • Often invisible under normal conditions
The size of the problem? • Over 500 lung cancer deaths in 2004 related to past silica exposure in construction • Over 10 a week • Research suggests silica is the second most important cause of occupational lung cancer after asbestos
UK accident v ill health deaths Other non-malignant Respiratory Disease Respiratory Disease Asbestosis Fatal Injury COPD Cancer
Roof tiles Many of the issues discussed are relevant to the cutting of roof tiles: • Cutting tiles produces silica dust • Roofers will breathe this in and are therefore at risk • Control measures are required to protect their health
Why do we need to tackle this? • To protect people from suffering ill-health • Ensure consistency of approach by industry and the regulator • Improve industry image – considered dusty • Legal duty under COSHH to adequately control exposure
How much is a problem? COSHH sets Workplace Exposure Limits for dust: General Dust • 10 mg.m-3 (inhalable) • 4 mg.m-3 (respirable) Respirable Silica • 0.1 mg.m-3 (8-hour TWA)
Tile cutting tasks Cutting or grinding • High energy processes that generate high dust levels • When working on tiles the dust contains high level of RCS
Management controls Arrangements: • An assessment(s) of the risk • They have given appropriate information, instruction and training. • Arrangements for the maintenance, examination and testing of control measures • Effective supervision, monitoring and review • Slips, trips and working at height
Controls • On-tool extraction OR • Water suppression • RPE/PPE • Training + OR
Tile cutting interim control solutions • Wet Cutting = • Dedicated cutting area • Adequate supply of water • Scaffold board protection • Additional use of RPE
Interim arrangements for setting out the roof Plan the work area on the top lift of the scaffold • Locate away from the side of the building e.g. on a loading bay area • Use sheeting to control slurry runoff • Place sacrifical material between the tile and the scaffold board • Move controls (on-tool extraction or water suppression and RPE) onto the scaffold by mechanical lifting aids • Additional measures may be needed to prevent slips, trips and falls e.g. brick guards • Ensure that there are no other trades working in the vicinity
Interim control solutions • Verge and Ridge Tiles • Cut with water suppression on scaffolding • Hip Tiles • Rough cut in situ or with water suppression on scaffolding
Interim position • Valley Tiles • Cut in-situ using Protection Factor 20 RPE
Agreement on control solutions • Made explicit that any such agreement is only interim in nature. • Operational Guidance – SIM 02/2010/01
Control solutions Water Suppression
Control solutions Water Sources
Control solutions • Water Suppression has other advantages: • Extends the life of expensive diamond blades • Helps prevent build up of dust in the machine workings
Control solutions • Issues associated with water suppression use: • Marking the cut line • Slurry generation • Wet legs
Control solutions On-Tool LEV is also an option.
Looking into the crystal ball New innovations and new roofing systems
What about RPE? Powered Respirator with Hood Half Mask (with P3 Filter) PF = 20
Respiratory protective equipment Disposable FFP3 Protection Factor = 20
Correct Mask Type: FFP3 Manufacturer product no. Class of Respirator: FFP3 European Standard Conformity mark & Notified Body
Make sure it will work Must fit correctly – ‘Fit testing’ Be worn correctly
What other PPE? • Waterproofs • Coveralls
HSE’s enforcement expectations Exposure to RCS is considered to constitute a: ‘serious health effect’
No control = ENFORCEMENT * = Task Specific
More information • Operational Instructions on tile cutting http://www.hse.gov.uk/foi/internalops/sectors/construction/021001.htm • Time to Clear the air – free leaflet http://www.hse.gov.uk/pubns/misc830.pdf • Time to clear the air! Using cut-off saws for cutting kerbs and flag paving – DVD http://www.hse.gov.uk/construction/cleartheair/index.htm • RPE and Fit Testing http://www.hse.gov.uk/news/2009/fit-testing-poster.pdfhttp://www.hse.gov.uk/pubns/fittesting.pdf
Thank You Any Questions?