Reducing the Risk of Silica Dust On –Tool Dust Extraction Systems Awareness Presentation Working Well Together SHAD, Durham, Sept 2012
Agenda On Tool Dust Extraction Systems Choosing Using Maintaining Construction Site Dust – What does it look Like? Why dust free is good for your business? Alternative Methods Start by listing the above subjects that will be covered in this training programme.
Choosing On-Tool Extraction On-tool Extraction is a system. Think carefully about key parts when selecting: Tool / Consumables Capture Hood Extraction Unit Tubing It’s a System approach Right tool for the job Correct fitting of tube Extraction unit to suit = most effective removal of dust
Choosing On-Tool Extraction Tool/Consumables Check that these allow effective removal of the dust Highlight that basics need to be achieved Start with correct tool for the application being done & consumable Then the consumable – left picture shows base of sander on side with perforated holes & vac tube attached highlight the sandpaper without perforated holes which comes in roles – if perforated sandpaper not used then the system doesn’t work! Explain the design of the diamond blade – done in this way to achieve optimum grinding & also to feed dust to the extraction point
Choosing On-Tool Extraction Capture Hood: Most important part. Can be designed in or retro-fitted. Check it: Is designed for the tool and the work being done. Sits as close as possible to the work surface when in use. Is easy to use and does not interfere with the work unnecessarily. Use DRS B as example of retro fitted capture hood Highlight DC230 as designed in Capture hood Explain design effort put in to achieve a designed in or retro fitted capture hood that doesn’t interfere with the work being done Pointless if affects this as the operative will not use it
Choosing On-Tool Extraction Extraction Source: Second most important part of the system: Choose an M (medium) or H (high) class unit. These are marked with a special warning label. (Note: an L class unit is only suitable for low toxicity dusts like gypsum) Make sure the unit can cope with the amount of dust the work will create. Lots of fine dust can quickly clog filters. Choose units with pre-filters, built-in ‘back-flushing’ filter cleaning mechanisms or similar devices. Think how regularly the unit will need emptying. Check the waste capacity is big enough (20/40/60L capacity) Achieves rating by meeting req specifications not just on type of filter but how the unit retains the dust for safe disposal M class minimum requirement as stated by HSE for silica dust extraction Highlight: M class specification sticker on front of vac must be present if deemed to have M class specification diameter selector for different sized tubing Bung for tube connection point in vac to stop dust escaping when transporting Demonstrate the backflushing on the vac – turn on after approx 15 secs the vac will automatically vibrate to loosen dust from filter – mention other methods are manual vibrate button on vac which operator needs to press only as good as the operator! At same time it reverses the flow for a second to aid unblocking the system This can also be done manually if further cleaning of filter req by blocking end of tube - demonstrate with hand
Choosing On-Tool Extraction Tubing: Check: It is of the right diameter and length for the work and the extraction unit. It fits securely to both the hood and unit. No tape! Use dust hood & demonstrate fitting – push in or click in depending on connection end -off tubing both in tool & vac Also diameter selector on vac for different sized tubing – needs to be same as tubing so achieve correct flow rate
Using On-Tool Extraction Training Provide the right instruction before on-tool extraction is used. Include information on: Selecting the right on-tool system. Pre-use checks and maintenance. Correctly using the system. Other controls that may be needed (e.g. RPE) and how to use them. Common faults, how to spot them and the action to take. What to do if there is a problem.
Using On-Tool Extraction Daily Checks Ensure the system works properly first time, every time. Concentrate on: Damage to parts of the system such as the hood or ducting. Repair or replace straight away. Replacing worn cutting discs etc Maintain the extraction unit’s flow of air. Check the airflow indicator (audible alarm) and any built-in cleaning mechanism works properly. Follow the manufactures instructions. Replace filters when needed. Clean the equipment regularly (e.g. wipe down). Do not let dust build up on working parts. Use m class vac to demonstrate audible warning when either full or blocked
Using On-Tool Extraction Use: Focus on: Following the method of work and manufacturer’s instructions Using the tool in the right way – e.g. move a grinder in the direction of the blade’s movement, not against it. Let the tool do the work Ensuring the capture hood is a close as possible to the work surface A good connection to both the captor hood and extraction unit. Use an adaptor if needed, not tape. Emptying the extraction unit regularly. Use disposable waste bags. Seal and place in the right waste container. Do not empty these bags to recycle them. Keeping the collected dust dry. Some extraction units are designed for both dry materials and liquids. Using them in this way when they are part of an on-tool extraction system can reduce the airflow needed for on-tool to work. Explain using manufacturers instruction manual to put together method statements – written in layman's terms easy to understand covers use/maintenance Show samples of correct dust bags, paper (for finer dust- sanding) & heavy duty plastic (concrete & rubble mixture – drilling/breaking) explain reason behind design of these perforated holes in plastic bag stops it sucking up to filter inside vac. Also paper bag has cover that can be pulled in place on removal from vac to seal it up. Emphasise dust collection & disposal rather than reusing bin them
Maintaining On-Tool Extraction Maintenance: Daily checks are not enough to ensure that on-tool extraction remains effective over a long period. A competent person should thoroughly examine and test all individual parts of the system(s) for damage, wear & tear at least every 14 months to ensure it meets the Manufacturer’s Technical Performance specifications. More frequent testing may be needed if regular wear and tear could limit the effectiveness of the system more quickly. Report – detailing the findings and any action needed. One report can be used to record the testing of many different parts provided each is individually identifiable. (Tool Service History Documentation) Key parts of a system do not need to be tested working together. The ‘Mix and Match’ nature of different parts and the variety of tasks they can be used for make this impractical. The correct system should be selected for the work in the first place. Mention our repair invoices which details Date of inspection/repair What was done in detail Mention that this can be used to put together tool serving schedule ie excell format etc
Construction Site Dust – What does it look Like?
The following series of slides show how dust can build quickly on a busy jobsite when several activities are happening at the same time. Each of the operatives in this fictional situation should be wearing RPE (dust masks) since they are working on dusty applications, however we know it is common for other workers to be working in the vicinity not wearing dust masks. Clearly, those at highest risk are those closest to the source of dust BUT it should be noted that these activities can affect others working in the area too. 1´´
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This shows the difference in atmosphere when a harmonised dust extraction system is used for each of the applications. Clearly the dust is reduced significantly and each of the operatives has a much clearer view of the work space. For visual effect use bags containing dust from application drilling/chasing both with & without a dust extraction system
DRS improves customer productivity no DRS Inhalable Dust [mg/m3] up to -99% no DRS Tool Lifetime up to + 60% Application Speed up to + 20% no DRS no DRS Consumable Lifetime* up to + 20% no DRS Cleaning Effort no DRS Respirable Dust [mg/m3] up to -99% up to – 15 kg/h Worker protection comes first But achieving this also gives benefits to the business Reduced wear & tear on bpoth the tool & consumables Dust extraction systems speeds up the process Worker Protection Longer Lifetime Labour Time Savings Results may differ based on operator technique, specific application, and tool/accessory condition. The need for additional measures must be evaluated by the responsible health and safety personnel on site. 21
Tools and a DRS solution are available for most applications Convertible Convertible Integrated Drilling Jig Sawing Drilling & Breaking Cutting & Grinding Grinding Cutting & Slitting Core Drilling Sawing & Sanding DRS Accessories DRS Accessories Most applications can be covered by a variety of tools either designed in or with retro fitted dust removal systems Vacs to complete the system
Hilti also offer “alternative methods” Alternative to drilling and fixing Alternative to manual and breaker demolition DX GX Wet Drilling Wet Sawing Vacs to complete the system If drs not possible consider direct fastening instead of drilling or diamonds Generally all manufacturers will offer advice on systems available When combined with our DRS solutions, Hilti has the best offer for reducing dust risk on the jobsite