Take control of dust · 4-7 Tackle dust at source on site A l ook inside Hilti’s dust research lab 10-11 Tools for dust control Contents 8-9 It’s time to take action on dust Welcome

Take control of dust

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How dust can wreck livesPermanent lung damage doesn’t need to be a feature of working on site – protecting the industry’s workers from the e� ects of construction dust can be tackled with a few simple steps

“Our objective is to raise awareness of the importance of good occupational health”


FOREWORDROBIN HOLDSWORTH

As a trade organisation, CONSTRUCT is keen to ensure that all of its 30 contractor member companies work in safe and healthy environments. To ensure that they are aware of the latest and potential legislation in all aspects of health, safety and the environment, it holds regular meetings for the members’ health and safety professionals.

CONSTRUCT also runs seminars

and training programmes on topics such as the e� ects of construction dust and how to minimise it on sites and in workshops. Our objective is to raise awareness of the importance of good occupational health. Although the HSE has set various maximum limits for dust inhalation depending on its type, CONSTRUCT is determined to work towards a zero-inhalation target.

To further encourage members, we run an innovation award for

The Construction Dust Partnership (CDP) was initiated by the Health and Safety Executive following research that identifi ed the industry as having high exposure to workplace dust. This exposure consequently results in high levels of respiratory disease including lung cancer, silicosis, chronic obstructive pulmonary disease (COPD) and asthma.

It can cause workers to die early, permanently damage their lungs, drastically reduce the quality of their life as they get older and have a signifi cant e� ect on their families. Symptoms arise from many repeated exposures over time. Too many people think to themselves “I’m only doing a quick job” and do not protect themselves. These little exposures add up over

health and safety, which this year was won by Hilti for its development of equipment designed to minimise dust at source. This equipment, which our members use for drilling and cutting concrete, as well as the

sawing of timber, helps us to get closer to our zero target.

By using such equipment inhalation of, for example, dangerous respirable silica dust, can be easily minimised. Such new equipment used in combination with other precautions, such as visors, shows how manufacturers are aware of the dangers and realities of work within the construction industry.

Robin Holdsworth is chief executive of CONSTRUCT

Towards zero inhalationTrade body CONSTRUCT wants to help raise awareness of the dangers of construction dust. Taking the right precautions and using the right equipment can make a huge di� erence to workers’ health

FOREWORDTHE CONSTRUCTION DUST PARTNERSHIP

the months and years and can give rise to serious health problems. Unfortunately, by the time the ill health e� ects are felt, you may have caused irreversible damage.

As we will see in this supplement, protecting workers from the e� ects of construction dust needn’t be di� cult or costly. Making simple, practical changes to the way jobs are done can greatly reduce the amount of dust created, help stop it from spreading in the air and prevent it being breathed in.

The CDP brings together organisations from across the industry to help protect workers against the devastating e� ects of breathing in construction dust.

Construction dust is a serious risk to health and not just an inevitable part of the job.

Visit the CDP website to take advantage of the free resources available: www.citb.co.uk/cdp

Without controls, the risk of dust exposure is high, as shown by the controlled experiment at Hilti’s dust laboratory – see p9

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Supplement editor Andrew Gaved

4-7 Tackle dust at source on site A look inside Hilti’s

dust research lab10-11 Tools for dust control

Contents

8-9

It’s time to take action on dust

Welcome to our supplement Take Control of Dust, which attempts to highlight the risks to workers from construction dust and to point towards risk reduction measures. Dust is a problem that is not unique to the construction industry, but the nature of the business we are in means that workers are exposed to its risks at virtually every point in the construction process.

It is the very fact that dust is so ubiquitous on construction sites – occurring during drilling, sawing, breaking, grinding and transportation – that has led health and safety experts to warn

that it could be ‘the next asbestos’ for the industry if not tackled head-on, because workers simply do not realise that the dust arising from concrete, tile, brick and mortar is so hazardous to health.

Because of exposure to silica dust, a shockingly high 500 people are estimated to be dying each year of lung cancer – and this is probably a conservative estimate. Now is the time to do something.

This supplement, the latest in a series of collaborations between Construction News and Hilti, aims to show the ways that dust can be

tackled at source, by use of on-tool extraction systems and by avoiding, where possible, the generation of dust in the fi rst place.

This is going to mean a change of culture for the industry – drastically reducing wall chasing or sawing, for instance, are moves that will not be achieved overnight, so it is vital to spread the message. Thus we are very pleased to be working closely with the Construction Dust Partnership, a cross-industry group whose information and expert guidance at www.citb.co.uk/citb will serve as important resources.

We can have a signifi cant e� ect on the health of our workforce. Only by taking a fresh approach to the problem will we be able to take control of dust. We hope you fi nd this a useful document to start the process of change.

Dust could be ‘the next asbestos’ for the construction industry

“Only by taking a fresh approach to the problem will we be able to take control of dust”

INTRODUCTIONANDREW GAVED

Take control of dust | 3www.cnplus.co.uk

A CONSTRUCTION NEWS SUPPLEMENT, IN COLLABORATION WITH:

“Construction dust is not just a nuisance; it can seriously damage your health and some types can eventually even kill.”

That isn’t just scaremongering; that is the straight from the mouth of the Health and Safety Executive, in the introduction to its guidance document on the subject, called CIS36.

The HSE has formed a cross-industry group called the Construction Dust Partnership – with representatives from contractors, hire companies and tool and safety gear manufacturers – in a bid to raise awareness of the problem and to help the industry to fi nd ways to avoid it.


Tackle dust at sourceThere are many e� ective ways to tackle dust on site. Appropriate use of the right equipment will have a positive impact on the health of the workforce – not to mention its productivity


Dust is an occupational hazard of site life, isn’t it? Everything, or almost everything, that is a construction activity creates dust – drilling, breaking, grinding, sawing. You name it.

But the message coming through loud and clear from those whose job it is to protect workers is that the construction industry needs to wake up to the problem of dust exposure, because it isn’t something that just makes you sneeze or cough – it is something that could ultimately kill you if you don’t take steps to prevent it.

The HSE also has some pretty compelling evidence – its latest statistics bulletin shows that there are almost 800 deaths every single year from silica-related lung cancer and 4,000 deaths from Chronic Obstructive Pulmonary Disease related to dusts, vapours and fumes. Although these aren’t all related to construction, it is clear that a signifi cant number of them will be, because the silica that causes the worst problems is found in concrete, mortar and sandstone, as well as bricks and tiles (see box on opposite page).

Potential for damageEvery time silica is drilled into,

sawn, ground smoothed, chased, sanded or broken up, it creates the potentially damaging fi ne dust RCS (respirable crystalline silica), which can travel deep into the lungs.

There is an urgency to the message because in addition to the most serious disease, there are other problems that the dust can cause – namely silicosis, in which lungs are scarred.

According to Chris Keen, occupational hygienist with the Health and Safety Laboratory, the ‘sharpness’ of RCS makes it particularly nasty: “RCS can go deep into the lungs and once down there, it stays there. Once breathed in, it stays there for life. It is sharp and abrasive, so it is doing damage and scarring the lungs.”

Unfortunately, it is not just silica dust that cause problems. The Construction Dust Partnership says: “Construction dust includes silica, wood and other dusts – eg gypsum from plasterboard. The e� ect of inhaling these highly hazardous particles can result in severe and irreversible respiratory illnesses. Builders and tradesmen carrying out jobs – including cutting paving slabs or roof tiles, wall chasing, grinding, sanding and sweeping – are all at risk if control measures are not in place and the correct protection is not worn.”

However, these risks are complicated by several factors: Firstly, dust disease takes a long time to manifest itself. “The long latency of diseases associated with construction dust exposure means that managing and controlling this risk is often misunderstood or overlooked until it is too late,” says the CDP.

Secondly, you don’t need to be exposed to a lot of dust to go over the exposure limit under the relevant legislation, The Control

OVERVIEWANDREW GAVED

European hub of Laing O’Rourke agreed: “Safety at Kier was absolutely on the top of the page of everything we did and a lot of our projects do dust monitoring, but the whole issue of health at work is something that has been ignored for far too long.”

This attitude is borne out by the HSE’s recent Safer Sites inspection campaigns, which have seen increased focused on health areas – the one this summer saw more than 60 improvement or enforcement notices handed out to construction fi rms for dust exposure failings, according to the HSE’s database.

But there is good news: fi rstly, the diseases are eminently preventable, if the exposure is limited appropriately; and secondly, there are a lot of ways to reduce dust exposure, from extraction systems to water suppression to alternative activities that don’t create the dust. Importantly, these measures aim to stop the dust, rather than merely defending against it. The message from the CDP and the HSL alike is that while it is essential to wear the appropriate type of mask – referred to as RPE (Respiratory Protective Equipment) – the main goal should be to stop dust at source, or where possible, avoid it altogether.

Exposure limitationMr Keen says: “You need to take it back to fi rst principles and, if possible, avoid cutting masonry on site – there will always be a measure of cutting required, but materials can be supplied in pre-cut lengths.”

This is welcome news for those tasked with health and safety on site, in that the control of dust on site should be more a question of selecting appropriate methods and equipment than of timing and measuring workers’ exposure.

A key element is to segregate work where possible, Mr Keen says, so that other workers are not exposed to the dust that has been created by someone else: “Even if they had controls in place for the original work, there will still be a dust risk.”


“There is a risk of signifi cant dust exposure at every stage of the construction process. The key is to keep things clean and to clean up the dust as soon as it is generated”

of Substances Hazardous to Health Regulations 2002 (more commonly known as COSHH). In fact, it is a tiny amount – like a small pinch of salt.

Hidden problemAnother problem is that the dust particles that do the most damage are too small to be visible to the naked eye and they hang in the air long after the construction activity has fi nished – astonishingly, as long as eight hours. Thus dust exposure is thus not just a problem for those who create the dust but for others around them on site.

Mr Keen says: “Only a small proportion of the daily exposure comes from the tools itself. The rest is from dust around the site – in an enclosed space the RCS dust will be airborne for hours. There is a risk of signifi cant dust exposure at every stage of the construction process. The key is to keep things clean and to clean up the dust as soon as it is generated.”

As a result of all this, many experts now believe that dust has the potential to become a time bomb for the industry if it is not tackled soon.

One expert, whose standing in the industry gives his view some authority, says: “The problem with construction is the exposure to RCS is so common for workers. It could actually be a bigger threat than asbestos – the di� erence is that nowadays, even the most dyed-in-the-wool worker knows to stop work when he fi nds asbestos. But for dust, people simply don’t recognise it as a risk.”

Some pretty high-profi le fi gures agree. Senior bosses at the recent Construction News summit were forthright on the need for action: Nick Pollard, chief executive of Balfour Beatty said: This industry has a long way to go – far, far more people die from work-related disease in our industry than ever die on construction sites. But the immediate concern has been very focused on construction site safety rather than on occupational disease.”

Paul She� eld, formerly chief executive of Kier and now managing director of the

Here is a breakdown of the HSE’s guidance on controlling construction dust:

Assess the risks Assess the risks linked to the work and materials. High dust levels are caused by one or more of the following: ■ Task The more energy the work involves, the bigger the risk. High-energy tools such as cut-o� saws, grinders and grit blasters produce a lot of dust in a very short time; ■ Work area The more enclosed a space, the more the dust will build up. However, do not assume that dust levels will be low when working outside with high-energy tools; ■ Time The longer the work takes the more dust there will be; ■ Frequency Regularly doing the same work day after day increases the risks.

Control the risksUse the following measures to control the risk. Stop or reduce the dust Before work starts, look at ways of stopping or reducing the amount of dust you might make. Use di� erent materials, or tools or other work methods. For example you could use: ■ The right size of building materials so less cutting or preparation is needed; ■ Silica-free abrasives to reduce the risks when blasting; ■ A di� erent tool – eg a block splitter instead of a cut-o� saw; ■ A di� erent method of work

altogether – eg a direct fastening system.

Control the dust Even if you stop some dust this way, you may do other work that could still produce high dust levels. In these cases, the most important action is to stop the dust getting into the air. There are two main ways of doing this: ■ Water Water damps down dust clouds. However, it needs to be used correctly. This means enough water supplied at the right levels for the whole time that the work is being done. Just wetting the material beforehand does not work. ■ On-tool extraction that removes dust as it is being produced. It is a type of local exhaust ventilation (LEV) system that fi ts directly onto the tool. This ‘system’ consists of several individual parts – the tool, capturing hood, extraction unit and tubing. Use an extraction unit to the correct specifi cation,

Sandstone

Concrete, mortar

Tile

Granite

Slate

Brick

Limestone

Marble

APPROX. CRYSTALLINE SILICA CONTENT OF MATERIALS

70-90%

25-70%

30-45%

20-45%, typically 30%

20-40%

Up to 30%

2%

2%



ie H (High) M (Medium) or L (Low) Class fi lter unit. Don’t just use a general commercial vacuum. ■ Respiratory protective equipment (RPE) Water or on-tool extraction may not always be appropriate or they might not reduce exposure enough. Often respiratory protection has to be provided as well. You will need to make sure that the RPE is: ■ Adequate for the amount and type of dust – RPE has an assigned protection factor (APF) that shows how much protection it gives the wearer. The general level for construction dust is an APF of 20. This means the wearer only breathes one-twentieth of the amount of dust in the air if the mask if used correctly; ■ Suitable for the work – disposable masks or half masks can become uncomfortable to wear for long periods. Powered RPE helps minimise this.

Consider it when people are working for more than an hour without a break;■ Compatible with other items of protective equipment; ■ Fits the user. Face fi t testing is needed for tight-fi tting masks; ■ Worn correctly. Anyone using tight-fi tting masks also needs to be clean-shaven.

Remember: RPE is the last line of protection. If you are just relying on RPE you need to be able to justify your reasons for this.

Other controls Depending upon the work you are doing you may have to combine these measures with other controls. Think about: ■ Limiting the number of people near the work; ■ Rotating those doing the task; ■ Enclosing the work to stop dust escaping. Use sheeting or temporary screens; ■ General mechanical ventilation to remove dusty air from the work

area (eg in enclosed spaces such as indoors); ■ Selecting work clothes that do not keep hold of the dust. You also need to make sure workers are doing the job in the right way and are using controls properly; ■ Train workers about dust risks and how this can harm their health; how to use the dust controls and check that they are working; how to maintain and clean equipment; how to use and look after RPE and other personal protective equipment (PPE) and; what to do if something goes wrong.

Review the controlsYou may already have the right controls in place, but are they all working properly? Check the controls work by: ■ Having procedures to ensure that work is done in the right way; ■ Checking controls are e� ective. Does the work still seem dusty? You might need to carry out dust exposure monitoring; ■ Involving workers. They can help identify problems and fi nd solutions;

■ Maintaining equipment: follow instructions in maintenance manuals;■ Regularly look for signs of damage. Make repairs; ■ Replace disposable masks in line with manufacturer’s recommendations;■ Properly clean, store, and maintain non-disposable RPE. Change RPE fi lters as recommended by the supplier;■ Carry out a thorough examination and test of any on-tool extraction system at least every 14 months. ■ Supervising workers. Make sure they use the controls provided; ■ Follow the correct work method; ■ Attend any health surveillance where it is needed.

You may have to put a health surveillance programme in place – if necessary, take advice on this from an occupational health professional.

Notes are from HSE guidance CIS36 are downloadable from the CDP site, with many other resources including toolbox talks: www.citb.co.uk/cdp


TOOL UP TO TACKLE DUST

Mike Mungroosingh, health, safety and environment leader for Expanded (part of the Laing O’Rourke Group) is one of those who believes dust has the potential to be the new asbestos for construction if not controlled effectively. The effects are cumulative and delayed. “You don’t know the danger until it’s too late,” he says.

Mr Mungroosingh started reviewing procedures on dust in April/June in expectation of the forthcoming health risk campaigns driven by the HSE on construction sites. Expanded, better known for concrete frame construction and design for manufacturing/assembly solutions, is also involved in piling, stonemasonry and demolition work.

“We have two main sources of dust – RCS and wood,” he says. “Two of the main tool operations – using handheld circular saws and various drilling/breaking tasks – can both generate levels above the Workplace Exposure Limit stated by the HSE.”

During the HSE health campaigns over the summer, Expanded received various unannounced visits to projects throughout the UK and the initial

feedback from inspectors focused Mr Mungroosingh’s mind further. “We were doing a small task on one of our projects that involved drilling five bolt-holes into the concrete slab and an HSE inspector observed one of the team sweeping the dust up with a broom, without controls in place,” he says.

Damping-down and RPE should be routine on a job like this, he notes, but on this occasion the operative was sweeping dry dust without a face mask. “The HSE’s first question was ‘has he received face-fit testing?’ The answer was ‘yes’ and we could demonstrate this via our records,” he says.

Dust reduction planMr Mungroosingh realised that this incident could have been prevented by ensuring that there was no dust on the floor in the first place, so set about looking at dust reduction solutions. “We have invested in various solutions that remove concrete dust as it is produced, thereby reducing the secondary risk to others on site, not just those drilling. Hollow drill pieces and dust extraction

attachments for drills were procured from Hilti, with both working very well in different environments.”

As a leading framework contractor, Expanded was able to discuss the dust extraction system for circular saws with Hilti. The manufacturer went away with findings highlighted by Expanded and then delivered a solution on time. “They don’t mess around,” says Mr Mungroosingh. “We are now collaborating with them on other solutions.”

In light of the HSE’s focus on dust controls, Mr Mungroosingh commissioned a consultant to monitor dust management on Expanded’s sites in the UK. In doing this, he demonstrated that with additional dust controls, his employees were consistently monitored at 50 per cent below the current Workplace Exposure Limit for dust. “That’s good because the consistency shows that our approach is effective,” says Mr Mungroosingh. “But 50 per cent below is only the start; the industry benchmark is ‘nil or negligible’ likelihood of a serious health effect. This can only be achieved when all the necessary control measures are in place and working effectively.”

“It is about recognising the hazards and creating less dust by whatever means possible. Now is the time to take action”

Dust: the legislative landscapeThe key piece of legislation on site governing dust exposure is COSHH, which sets out maximum Workplace Exposure Limits or WEL for dust – whether inhalable, referring to the entire inhalable portion of the dust through mouth and nose, or respirable, relating to the portion of the respirable dust that can reach the pulmonary alveoli due to its small particle size.

As can be seen from the table, the amounts described are miniscule. If you imagine a kilogram bag of sugar is a million mg, it soon becomes clear that 5 mg is an amount of dust that will be virtually impossible for the average site worker to physically see, let alone measure – and the RCS respirable limit is a fi ftieth of that, at 0.1 mg.

Thus it is clear that the law puts the emphasis on workers to prevent the dust occurring in the fi rst place – the important thing will be to ensure that they are: a) using the best possible methods to reduce dust and;

b) that they are properly protected. For those tasked with ensuring health and safety on the site, however, the exposure levels will be crucial. Summarised in the table below are the WELs for di� erent types of dust, over eight hours, expressed as a concentration of dust particles in a volume of air.

The Construction Dust Partnership stresses in its toolbox talk that this eight-hour daily Workplace Exposure Limit shouldn’t be looked at as a legal minimum that can be used in isolation. It says: “Instead it is a maximum concentration of a substance that should be found in the air, averaged over the reference period, after good control principles have been applied.”

As Mr Keen sums up: “It is about recognising the hazards

and creating less dust by whatever means possible. Now is the time to take action.”

“The WEL for silica is the same as that for arsenic,” the CDP adds. “Would you want to take that amount of arsenic daily as a ‘safe’ limit or would you look to put in good controls fi rst?”

Tool standardsThe other key piece of legislation is a new European standard, EN 50632, which has been created specifi cally for measuring dust created by power tools in a ‘real

world’ situation and the e� ect of their on-tool dust extraction, where appropriate.

This standard, due to come into force in 2015, is expected to become a crucial part of the landscape. HSL ventilation expert John Saunders says the standard is welcome: “There can be just as many problems from using the wrong tool or the wrong extraction. There has previously been no measurement for extraction, so a lot of the systems haven’t been tested. Extraction systems mustn’t be designed in isolation and they must be designed for continual use.

“The standard will allow people to compare like with like – and it will enable manufacturers to compare the e� ectiveness of on tool extraction and to design their tools accordingly.”

The following pages are intended to show readers the di� erent ways that dust can be tackled – and is already being tackled – on site. But at the same time we want to highlight how choosing equipment that is appropriately designed and using it properly can have a signifi cant positive impact on workers’ health and can improve productivity at the same time.

Dust Type Inhalable Respirable

RCS N/A 0.1 mg/m3

Wood 5 mg/m3 N/A

COSHH DUST LIMITS

■ Look for a Technical solution, ie using equipment methods; ■ If that isn’t appropriate, seek an Organisational solution, such as job rotation or halving the work time, to ensure that the workers stay under exposure limits; ■ As the fi nal line of defence only, protect the individual with Personal Protective Equipment.

Clearly within this protocol, it is fi nding the best equipment solutions that will hold the key to reduced exposure.


Introducing Mr DustA look inside Hilti’s dust research lab in Kaufering, Germany gives an insight into the investment the manufacturer is putting into the technology of dust extraction

“You have to factor in running costs if you are serious about getting value for money”


The importance of tackling dust was recognised early by Hilti, which established its own dust research department six years ago.

Dust-related activities are led by Andras Biczo, who was engaged by the manufacturer to tackle the issues, after six years in researching the subject at university. Along with running the test programmes for Hilti’s equipment, one of Mr Biczo’s key roles has been to collaborate with other tool manufacturers in the writing of EN 50632. As a result of all this, Mr Biczo is one of the world’s top authorities on construction dust and tools – it is no surprise that within Hilti he goes by the name of Mr Dust.

Mr Biczo says that controlling dust on site isn’t simply a matter of focusing on the tool operation, but also on the dust that has already been created: “Dust is created when the base material is broken by impact, abrasion, crushing, or grinding,” he says. “But also through the release of previously generated dust during operations such as loading and transporting; and through recirculation of previously generated dust by wind or by the movement of workers and machinery.”

The second essential to bear in mind, he says, is that a dusty worksite does not only risk disease, it also slows the work in several ways – at once reducing visibility and potentially requiring increased concentration (or alternatively, reducing concentration altogether through constant sneezing). He adds that this potent combination could also potentially increase the risk of injuries. Mr Biczo also o� ers a handy aide memoire for dealing with dust – go for the TOP.

Inside the test chamberAt the heart of Mr Biczo’s laboratory is the test chamber, within which the company performs its dust generation tests. To meet the terms of EN 50632, tools have to be tested in a 200 cu m chamber, which is both temperature-controlled and humidity-controlled; and the dust collected using samplers attached to the operative at three strategic points – near their airway to capture inhalable dust, and either

side of the lungs for respirable dust. The EN standards are so stringent that the fi lters used for sampling need to be weighed in controlled humidity conditions using a scale to an accuracy of one-hundredth of a milligram (0.01 mg).

As a measure of the investment required, Hilti’s gravimetric measuring equipment, which requires calibration every six months, costs 11,000 euros alone.

EN 50632 requires that the tool is used for a period of an hour and the operation repeated three times, with the average taken of the three volumes of dust collected. The new standard is good news for the industry in that it will allow tool manufacturers to have the confi dence to publish their dust credentials against a universal benchmark.

The goal for end users and manufacturers alike will be that the dust generated by their tools falls below the daily Workplace

RESEARCHANDREW GAVED

“Dust is created when the base material is broken by impact, abrasion, crushing, or grinding”

Hilti’s ‘Mr Dust’ : Andras Biczo

picture below) whereas the competitor had early signs of dust around the application area. Mr Biczo says that this competitor tool, although it looks to have all the right kit in all the right places, did not meet the eight-hour Workplace Exposure Limit when tested to EN 50632 standards.

But the next demonstration in the context of the message to sites arguably has even more impact. Mr Biczo instructs his assistant to remove the extractor hood from the competitor tool, to show the risks from a tool without any on-tool extraction. The fact that Eberhard fi rst insists on upgrading his full-fi t face mask to a heavy duty respirator is perhaps a clue. Within seconds, he is having to guide his tool through clouds of dust. Inside a minute, he has disappeared completely. The risk from unprotected dust in a confi ned space is thus made very real to those of us observing (from the safety of behind a window).

According to Hilti, the impact of Mr Dust and the research facilities is equipment better designed for


Exposure Level, as it will avoid sites having to rotate workers or other defensive measures.

Hilti is proud of the fact it has a range of dedicated extraction systems designed specifi cally for use in conjunction with its drills, sanders and cut-o� saws, and that these are equally optimised for use with its M-class vacuum cleaners. The fundamental for Mr Dust is that dust extraction simply has to be a system approach – mixing and matching di� erent dust extraction components, taking a vacuum here and a dust hood there, simply will not provide the most e� cient way to remove the dust.

System harmonySafety bodies agree on the importance of a ‘system’ approach. German safety body BG BAU said: “The essence in future will be to prompt the fi rms only to use power tool systems recommended and harmonised by the manufacturers.”

But Mr Biczo is fi rmly of the belief that when it comes to dust exposure, not all systems are created equal. Whereas the full range of Hilti systems – meaning an integrated system of tool plus extraction device plus vacuum cleaner – all meet the eight-hour Workplace Exposure Limits, measured to the standards of EN 50632, he says such a description cannot be applied to every manufacturer’s equipment. The graph, right, shows one recent test result of the Hilti’s diamond cutter the DCH 300, versus a competitor.

Mr Biczo gives Construction News a demonstration. He equips faithful test operative Eberhard with the appropriate dust sampling equipment and respiratory controls and dispatches him into the test chamber with fi rstly a Hilti diamond cutter and then a well-known competitor.

While both have hoods and their own integrated extraction systems, it is soon clear after only ten minutes that there is a big di� erence between the ability of the systems to remove dust from the worksite. The Hilti leaves no discernible dust trace at the worksite, leaving the cut groove relatively clean and visible (see

dust removal, with not only more types of system than rivals – it boasts 70 di� erent solutions, covering 95 per cent of its tool range (its heaviest breakers are not yet covered) – but technology designed to work with the tool, rather than being a ‘bolt-on’ solution.

Hilti’s range of solutions breaks down into three areas: integrated extraction; extraction accessories for use with its M-Class vacuum cleaner; and, where accessories aren’t available, vacuum only.

Hilti’s integrated DRS (Dust Removal System) has the obvious advantage of not needing the additional power consumption or weight of the vacuum – and it is cordless. Available for the TE small drill range, this is a motorised dust removal system, powered by the tool’s battery, that can also be used to ‘hoover’ the hole free of dust. Because it is a dedicated system, it is also optimised for the drilling process, with a robust fi lter.

Drill downThe next class is the range of drilling extraction adapters – which come in a wide variety of shapes and sizes to match the equally wide range of drill bits for combi-hammers. The DRS-Y system provides for a tube adaptor for each type of drill bit to ensure that the optimum amount of dust is collected – dust exposure is well below the WEL for both inhalable and respirable dust. There are di� erent versions available for hammer drilling, chiselling – and

for the ultimate in dust removal, Hilti’s innovative hollow drill bit (see overleaf).

For drilling and chiselling applications there are additional advantages to an e� cient dust extraction system beyond health – a cleaner hole will have obvious productivity advantages, from the ability to drill quicker, unimpeded by debris, to avoiding the need for post-drilling clean-up. In applications such as chemical anchoring, where a clean hole is essential for the resin to bond, the installation process is far quicker. But there is also a key knock-on e� ect, certainly as far as the DRS-Y is concerned, in that the additional weight of the system dampens out vibrations, reducing the hand-arm vibration exposure by up to 45 per cent.

The company points out that not every tool on the market has a dust removal system that is dedicated to the individual combi model. At Kaufering, the team demonstrated a rival system that depended for its e� ciency on attaching to the wall being drilled, which presents clear disadvantages on uneven or crumbling surfaces.

Arguably the tool system that most demonstrates the distinction between models best is Hilti’s DG 150 grinder. “Many tools’ dust extraction is not designed for the tool itself but is an adaption,” says Business Unit Diamond Systems product manager diamond drilling Inserts Steven Bruyndonckx. He says that some rivals use a bag to collect the dust, which doesn’t provide the suction of its version that connects straight to the vacuum cleaner. Its hood is designed to cover the entire cupwheel and the wheel itself contains air holes for improved airfl ow. It also uses a twist-to-fi t connection, whereas others require keys and the like.

“It is fi nding the best equipment solutions that will hold the key to reduced exposure”



Tools for dust controlThe Hilti DRS technology o� ers an impressive array of solutions designed to minimise risk

Hilti dust expert Andras Biczo says that the correct type of vacuum is the fundamental start-ing point in the war against dust: “For construction dust, you need at least an M class with the appro-priate fi lter. An ordinary industrial cleaner is not good enough and neither even is a HEPA fi lter, as it is not robust enough for silica.”

This view is confi rmed by the HSE, which has the following guidance on vacuums in its guidance on on-tool extraction: ■ Choose an H (High) or M (Medium) class unit. These units provide e� ective and reliable extraction capability and are fi tted with low-fl ow indicators. Don’t just use a HEPA fi lter in a general commercial vacuum. Note: An L (Low) class unit is only suitable for lower-toxicity dusts such as gypsum in plasterboard. ■ Check that the unit creates and maintains enough air suction to cope with the dust that the work will create (manufacturers/suppli-ers can advise). It needs to remove the dust as fast as it is created. ■ Fine dust can quickly clog fi lters. Choose units with pre-fi lters, built-in ‘back-fl ushing’ fi lter cleaning mechanisms or similar devices. ■ Think how often the unit will need emptying. Check the waste capacity is right for the work.

Hilti claims its VC 20 and 40 UM vacuum cleaners have several features that give it an advantage. The key move has been to put the motor and hoses in the top half of the machine, leaving the bottom half for the dust. This avoids main-tenance problems and provides easier emptying, as well as allow-ing the highest possible capacity.

Other features include an auto-matic fi lter cleaning function that uses a brief reversal of the air func-tion, providing a blast of air, rather than a mechanical shaking action,

thus avoiding loss of suction. There is also an audible alarm, which in conjunction with the electronic fl ow metering, alerts the user when suction is inadequate because of fi lter clogging or kinked hoses.

Another key distinction is that the company also has a cordless version of the vacuum system, where the cleaner itself becomes a battery charging unit for the tool. The whole dust extraction system can thus be run without plugs or generator.

When one of Hilti’s M-Class vacuums goes into its Tool Service Centre in Glasgow it is subjected to a battery of tests to ensure that the key elements of a properly functioning fi lter and appropriate air fl ow are in place. For Hilti in turn, this means the Glasgow facility having HSE-recommended air fl ow metering, which itself has to be calibrated at regular intervals, and on having an in-house fi lter testing machine to ensure the integrity and performance of the fi lter media.

On site, some people are not treating their vacuum cleaners with the appropriate respect for something designed to protect their health at risk in the process. The vacuum servicing specialists have plenty of tales of such behaviour: for instance workers punching holes in the dust fi lter because the suction on the vacuum had dropped (and thereby not only stopping it preventing dust escape, but stopping it working altogether), or even of appropriating paper car radiator fi lters instead of the more robust plastic M-class version that should be fi tted.

Given that a fi lter clogged with dust will ultimately burn out the motor, simply cleaning the fi lter earlier will improve operating time, Hilti contends.

Hilti is convinced that the rigour it applies to servicing can have a direct impact on dust

Vacuum

■ Compact and easy to handle, empty and transport ■ M class filters with automatic filter cleaning technology■ Hilti provides airflow calibration and certification to comply with HSE guidance, along with suction calibration■ Fibreglass reinforced containers doesn’t dent, preserving capacity■ Suction hose at the top maximises ultimate tank capacity■ Designed for wet and dry site conditions■ Audible alarms to warn if container is full■ Cordless and integrated power socket versions available


The specialist hirers

HSS Hire As we all know, the potential hazards that can arise from dust in the workplace are a great cause for concern. Here at HSS, safety comes first so we continually work with both customers and manufacturers alike to stay at the forefront of product innovation – particularly where health and safety is concerned. A united approach has helped us to develop products that reduce dust exposure effectively and we also invest in good alternative methods like direct fastening, diamond drilling and water suppression cutting.Emma Hoten, group procurement director

One Stop HireThe dust created from cutting and grinding on site has always been a major problem for our customers. We always try to keep them advised of the best solution for each application, whether that be suppression or extraction, along with the appropriate level of RPE [Respiratory Protection Equipment]. We also offer various types of training courses such as COSHH and Face-fit from our training division.

We have recently seen a large increase in demand for M Class dust extraction for use with the cutting and grinding equipment. We recently added 50 of Hilti’s VC 40-UM dust vacuums and expect this number to increase as we phase out our L Class fleet, as we have been impressed with their reliability.James Brown, safety, environment & training manager

SpeedyWe appreciate the issue of dust and the risk to health it poses – our award-winning Safety From the Ground Up campaign includes dust as one of the four main topics.

Our clients have found the innovative Hilti products have offered practical solutions, in particular the DG 150 diamond grinder, where the dust removal hood has provided high performance

and effective dust control.Wendy Bates, innovation & client experience director

The specialist contractors

Specialist Cutting ServicesSpecialist Cutting Services strives to eliminate health hazards within the workplace, not only to protect our employees but also to protect our clients and their subcontractors, the general public and the environment.

We were invited to use Hilti’s combis and angle grinders with dust extraction systems on demonstration terms in various environments including bottling plants, food factories, pharmaceutical production areas, prisons and hospitals.

Our operatives have found that the Hilti DCG230/300 angle grinders with extraction units and guards perform particularly well. Operatives appreciated factors such as the vacuums’ filters clearing themselves automatically. One said: “We don’t have to bang the filters against skips to clean them.”

Attachments are robust and click or push together easily with no need to use gaffer tape for sealing ill-fitting hoses.

As a second control measure, Specialist Cutting Services Limited has, over the past six months, worked at making sure its workforce are 100 per cent compliant on respiratory products. Julian Bonner, health and safety Manager

Mitchellson GroupThe health and safety of our workforce is our top priority, so our aim is to eliminate construction dust at source. We trialled the TE-YD hollow drill bit range and were so impressed we now stock and use them – the idea and design is so simple but so effective. Individuals using the TE-YD hollow drill bits like working with them as they provide increased protection from the dust and when they drill holes they don’t need to clean them out, in effect making their tasks that little bit easier.Joe Mitchell, HSQ&E Manager

HOW THE SUPPLY CHAIN IS HELPING TO REDUCE DUST

GrindingThe DG 150 grinder is claimed to bear out the Hilti ethos that a dedicated extraction system design provides the optimum results. ■ Height-adjustable dust hood ■ Specially designed cupwheels ■ Cupwheels completely covered by the hood■ Keyless design enables access to edges

SawingThe DCH electric diamond cutter features:■ Dust extract system designed to take the maximum amount of dust away from the cut site by being positioned ahead of the blade, rather than above it

Drilling/Chiselling/Coring■ The DRS-Y extraction system uses a universal extraction fitting, together with dedicated adaptors for drilling, chiselling or short coring, to take dust away from the point of impact ■ Use of DRS-Y claims to reduce inhalable dust by 98% in chiselling and 99% in drilling and coring, while reducing respirable dust by 97-99% in the same applications

The ultimate dust solution is Hilti’s TE-CD or TE-YD hollow drill bit, which takes the dust away from the hole the instant it is generated. This has a significant effect on productivity.

Don’t let dusttake your

breath away

www.citb.co.uk/cdp

Regularly breathing in construction dust can wreck people’s lives.

The Construction Dust Partnership is working with organisations across the industry to help protect workers against the devastating effects of breathing in construction dust.

Documents

Take control of dust · 4-7 Tackle dust at source on site A l ook inside Hilti’s dust research lab 10-11 Tools for dust control Contents 8-9 It’s time to take action on dust Welcome