Hand-held Masonry Saws with Vacuum Dust Control

Hand-held masonry saws with LEV capture airborne contaminants at the source by drawing the dust into a vacuum receptacle.

Description:

Cutting bricks, blocks, stone, concrete and other masonry materials generates a large amount of dust that may contain high levels of crystalline silica and create a hazard for everyone in the vicinity.  Increasingly, nano-enabled masonry products are being used in construction that can also expose workers to inhaling engineered nanomaterials when the products are being cut. Concrete roofing tiles that contain nano-size titanium dioxide are an example.  Vacuum dust controls exist for electric hand-held masonry saws (also called “cut-off,” “chop,” and “concrete” saws).  The size of the blades used with these saws varies depending on the manufacturer and model.  While it is common to find them with blades ranging in size from 12 to 16 inches, there are versions with smaller blades.  A vacuum dust control (or local exhaust ventilation) for a hand-held masonry saw typically consists of a vacuum with a disposable filter (a high efficiency particulate air –HEPA–filter is recommended when practical), and a hose attached, either directly or with an adapter, to a hood or shroud that partially encloses the blade. The vacuum draws air and dust from the blade, the point of dust generation, into the hood where it is transported through the hose into the vacuum's bag or reservoir.

The following are examples of commercially available saws and compatible vacuums.  Note: The saws and vacuums listed below may be compatible with other models and brands.  Additional information on compatibility may be obtained from the manufacturers.

Hilti DCH 300 Hand-held Electric Diamond Cutter and Hilti VC 40-U HEPA Vacuum Set

Bosch 12-inch Abrasive Cut-off Saw 1364 and Bosch Airsweep™ 13 Gallon Wet/Dry Vacuum with Power Broker™

CS Unitec  9-inch Cut-off Saw with Dust Collection and CS Unitec HEPA Vacuum with HEPA Filtration

Husqvarna K 3000 14” Vac Electric Power Cutter and compatible Dustcontrol DC 3900c Vacuum

Makita 14” Angle Cutter 4114 and compatible Dustcontrol DC 3900c Vacuum

Hilti DCH 300 Hand-held Electric Diamond Cutter and Hilti VC 40-U HEPA Vacuum Set
 

The DCH 300 is used to cut reinforced concrete, granite, curbstone, slabs, brick, masonry blocks and other masonry materials.  It is compatible with the VC 40-U vacuum with a HEPA filter.  The Hilti vacuum set includes the vacuum, HEPA main filter, 20 fleece bags and a hose adaptor.  A vacuum hose (1.42 inches x 16 feet) for concrete and masonry applications must be purchased separately from Hilti.  See video of the DCH 300 with Dust Removal System at: DCH 300 Demo #1 or DCH 300 Demo #2.  The saw is also compatible with Dustcontrol brand vacuums, when used with the appropriate adapter (Dustcontrol part number 42497, $20 – see details on the Dustcontrol vacuums below).

Equipment Model Cost*
12-inch Electric Diamond Cutter DCH 300 $900
Vacuum with HEPA Filter VC 40-U $1,050
Vacuum Hose for concrete/masonry 00203867 $110
Total List Price   $2,060

* Estimates based on retail prices found on-line as of 8/2011 unless otherwise noted.

Hilti Saw Specifications:
o    Blade diameter: 12-inch diamond blade
o    Maximum cutting depth: 4.7 inches
o    Maximum blade speed : 4,900 RPM
o    Weight of saw: 20.7 pounds
o    Saw power requirements: 120 volts, 20 amps
o    Diameter of connection on hood/shroud: 1.15 inches
o    Diameter of connection to vacuum: 1.42 inches
o    Ergonomic design
o    Sound pressure level : 106 dBA  (OSHA Permissible Exposure Limit is 90 dBA for an 8-hour time-weighted average)
o    Click here for more details on the DCH 300 and related products: Hilti DCH 300
o    Hilti also manufactures the DCH 230 with a 9-inch blade, which is compatible with its vacuum systems. Click here to learn more about the Hilti DCH 230
Hilti Vacuum Specifications:
o    Air flow rate (maximum): 129 cubic feet per minute
o    Dust capacity: 9.5 gallons or 88.2 pounds
o    Weight: 32.2 pounds
o    Filter cleaning: automatic, every 15 seconds
o    Power requirements: 120 volts, 10 amps
o    Hose adapter reduces diameter to 1.15 inches for connection to the saw
o    Meets the EPA lead Renovations, Repair and Painting (RRP) rule for HEPA vacuums when used with the HEPA main filter
o    Click the link for more details on the VC 40-U with HEPA and related products: Hilti VC 40-U Vacuum;
o    Click here for more details on the vacuum hose required and related products: Hilti Vacuum Hose & Accessories
o    Hilti also manufactures a smaller VC 20-U Vacuum cleaner with a HEPA Filter.  This product includes the vacuum, HEPA main filter, 20 fleece bags, 1 hose (1.42 inches x 15 feet), and a hose adaptor.  The dust capacity is 5.5 gallons or 50.7 pounds and the vacuum weighs 28.7 pounds. Click here  to learn more about the Hilti VC 20-U Vacuum Pack with HEPA Filter.

Bosch 12-inch Abrasive Cut-off Saw 1364 and Bosch Airsweep™ 13 Gallon Wet/Dry Vacuum with Power Broker™

The Bosch 12-inch Abrasive Cut-off Saw is used to cut concrete cinder brick, concrete forms, 1/8” concrete wire mesh, and other masonry products.  The 12” Abrasive Cut-off Saw is compatible with the Bosch Dust Extraction Guard and the Bosch Airsweep™ 13 Gallon Wet/Dry Vacuum with Power Broker™.  The Bosch vacuum set includes the vacuum, and a 1.38-inch (35mm) x 9.85 feet locking hose, 2 filters and one dust bag.  The saw is also compatible with Dustcontrol brand vacuums, when used with the appropriate adapter (Dustcontrol part number 42497, $20 – see details on the Dustcontrol vacuums below).

Equipment Model Cost*
12-inch Abrasive Cut-off Saw 1364 $825
Dust Extraction Guard 1605510215 $380
AirsweepTM 13 Gallon Wet/Dry Vacuum with Power BrokerTM 3931A-PB $600
AirsweepTM HEPA Vacuum Filters VAC019 $155
Total List Price   $1,960

*Estimates based on retail prices found on-line prices as of 8/11, unless otherwise noted. 

Bosch Saw Specifications:
o    Blade diameter: 12-inch diamond blade
o    Maximum cutting depth: 3-7/8 inches
o    Blade speed: 5,000 RPM
o    Weight of saw: 24.5 pounds
o    Saw power requirements: 120 volts, 15 amps
o    Diameter of the connection to vacuum: 1.38 inches
o    Click here for more details on the Bosch 12-inch Abrasive Cut-off Saw
o    Compatible with the Bosch Dust Extraction Guard - for more details click on: Dust Extraction Guard.
Bosch Vacuum Specifications:
o    Hose Port Inside Diameter: 2-1/4 inches
o    Air flow rate (maximum): 130 cubic feet per minute
o    Vacuum suction pressure: 9.76 inches (248 millibars)
o    Dust capacity: 13.3 gallons (gross)
o    Weight: 45.7 pounds
o    Filter cleaning: Pulse-Clean™ electromagnetic filter cleaning
o    Airsweep™ HEPA Vacuum Filters (Model VAC019) may be used
o    Power requirements: 120 volts, 11 amps
o    Click the link for more details on the Bosch Airsweep 13 Gallon Wet/Dry Vacuum with Power Broker
o    Optional Airsweep™ Vacuum Hose Adapters can be used to connect 35mm hoses to the vacuums with ports for 1-1/4, 1-1/2 and to 2-1/2 hoses.  Click the link for more details: 2-1/2 inch Vacuum Hose Adapter

CS Unitec  9-inch Cut-off Saw with Dust Collection and CS Unitec HEPA Vacuum with HEPA Filtration

The CS Unitec 9-inch Cut-off Saw with Dust Collection is used to cut concrete, masonry, block, brick, natural stone and other masonry materials.  It is compatible with the CS Unitec CS 1225 H HEPA Vacuum. The vacuum set includes the vacuum, HEPA filtration (2 filters, P/N 419190), a 15-foot hose, tool adapter and 25-foot cord.  With the appropriate adapters, the CS Unitec saw is also compatible with Dustcontrol vacuums (Dustcontrol adapters part numbers 2115 or 2120, $20 to $30), and the Bosch Airsweep Vacuum (Bosch adapter part number VAC024, $30).

Equipment Model Cost*
9-inch Cut-off Saw with Dust Collection A20/4D $540
HEPA Vacuum Set with HEPA Filtration 1225H $600
Total List Price   $1140

* Estimates based on on-line prices as of 4/10, unless otherwise noted

CS Unitec Saw Specifications:
o    Blade diameter: 9-inch diamond blade
o    Maximum cutting depth: 2.5 inches
o    Maximum blade speed: 4,500 RPM
o    Weight of saw: 15 pounds
o    Saw power requirements: 120 volts, 15 amps
o    Outside diameter of connection to vacuum: 1.5 inches
o    Click the link for more details on the CS Unitec Model A20/4 and related products: CS Unitec 9-inch Cut-Off Saw
CS Unitec Vacuum Specifications:
o    Air flow rate (maximum): 130 cubic feet per minute
o    Maximum static pressure: 98 inches of water
o    Dust capacity: 6.6 gallons
o    Weight: 24.3 pounds
o    Electromagnetic Pulse Cleaning System maintains maximum airflow and suction with automatic filter vibration.
o    Vacuum hose is 2 inches in diameter and 15 feet long and comes with an adapter for connection to the 1.5-inch outside diameter vacuum port
o    Wet vacuuming capability with sensor for automatic shut-off to protect motor and filters
o    Click the link for more details on the CS 1225 H HEPA Vacuum and related products, including the larger CS1500 H with a 13 gallon capacity, and the CS 2000 - Water Recycling and Slurry Containment Vacuum: CS 1225 and Other Models

Husqvarna K 3000 14” Vac Electric Power Cutter and compatible Dustcontrol Vacuum

The Husqvarna K 3000 Vac Electric Power Cutter is used to cut concrete, masonry, block, brick, natural stone and other masonry materials.  It is compatible Dustcontrol models when used with appropriate adapters.  These vacuums range in price from $1,300 to $4,900.  For example, the Dustcontrol 3800 vacuum is compatible when used with the 42497 adapter and product 2114 connection sleeve.  The vacuum includes:  a 1.5-inch x 15 feet hose, plastic waste bags or a reusable waste container, a fine filter and a HEPA filter.  The saw is also compatible with the Husqvarna DC 1400, 3300 and 5500 vacuums.  The Husqvarna vacuums range in price from $2,200 to $11,000 and weigh between 110 and 474 pounds.

Equipment Model Cost*
Electric Power Cutter K3000 Vac $900
Dustcontrol Vacuum DC3900c ~$3,900
Dustcontrol Multi Connection Hose Adapter 42497 $20
Dustcontrol Connection Sleeve 2114 $31
Total List Price   $4,851

* Estimates based on on-line prices as of 8/11, unless otherwise noted. 

Husqvarna Saw Specifications:
o    Blade diameter: 14 inch diamond blade
o    Maximum cutting depth: 4.7 inches
o    Maximum blade speed: 4,500 RPM
o    Weight of saw: 15 pounds
o    Saw power requirements: 120 volts, 15 amps
o    Diameter of connection to vacuum: 1-1/8 inches
o    Sound pressure level : 95 dBA  (OSHA Permissible Exposure Limit is 90 dBA for an 8-hour time-weighted average)
o    Click here for more details on the K3000 Vac
Dustcontrol, Inc. Single Phase Dust Extractors 3900c
See below for more details.

Makita 14” Angle Cutter 4114 and compatible Dustcontrol DC 3900c Vacuum

The Makita 14 inch Angle Cutter is used to cut concrete, stone, block and other masonry products.  It is compatible Dustcontrol models when used with appropriate adapters.  These vacuums range in price from $1,300 to $4900.  For example, the Dustcontrol 3800 vacuum is compatible when used with the 42497 adapter and product 2114 connection sleeve.  The vacuum includes:  a 1.5-inch (38mm) x 15 feet hose, plastic waste bags or a reusable waste container, a fine filter and a HEPA filter.

Equipment Model Cost*
14-inch Angle Cutter 4114 $1,000
Dustcontrol Vacuum DC3900c ~$3,900
Dustcontrol Multi Connection Hose Adapter 42497 $20
Dustcontrol Connection Sleeve 2114 $31
Total List Price   $4,951

* Estimates based on on-line prices as of 6/2011, unless otherwise noted. 

Makita Saw Specifications:
o    Blade diameter: 14 inch diamond blade
o    Maximum cutting depth: 5 inches
o    Blade speed: 3,500 RPM
o    Weight of saw: 23.6 pounds
o    Saw power requirements: 120 volts, 15 amps
o    Built-in vacuum attachment port for efficient removal of dust and debris. Diameter of connection to vacuum: 1-1/8 inches (29 millimeters)
o    Click here for more details on the 14” Angle Cutter and related products: Makita 14" Angle Cutter
o    Makita also manufactures the 12” Angle Cutter that is compatible with Dustcontrol vacuum systems. Click here to learn more about the Makita 12" Angle Cutter

Dustcontrol, Inc. Single Phase Dust Extractors
o    Cyclonic pre-separator - this system collects the majority of particles before they reach the filter, and reduces the amount of dust that collects on the filter
o    Filtration: a fine filter, rated to remove 99.9 percent of particles, followed by a HEPA filter, rated to remove 99.95 percent of 0.3 micron particles (the most penetrating size
o    Features a “reverse air pulse cleaning system”
o    Vacuum hose inlet diameter: 2 inches
o    Sound Pressure Level: 68 to 75 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average is 90 dBA)
o    Click here to learn more about the Dustcontrol vacuum models


Risks Addressed:

Inhaling silica dust may cause silicosis or lung scarring with prolonged exposure.  Silicosis is an incurable, sometimes fatal, disease.  Exposure to silica also causes lung cancer and other lung diseases including chronic obstructive pulmonary disease (COPD) and tuberculosis, and has been linked to renal disease and rheumatoid arthritis.  A report by OSHA noted that studies “show that using a handheld masonry saw to cut bricks, concrete blocks and similar materials can result in hazardous levels of airborne silica if measures are not taken to reduce dust emissions.  Operating a handheld masonry saw outdoors without dust controls can produce silica exposures in excess of 14 times the Occupational Safety and Health Administration’s (OSHA) permissible exposure level (PEL) for respirable crystalline silica in construction of 50 ug/m3 (micrograms per cubic meter of air, which is the same as 0.05mg/m3) as an 8-hour time-weighted average (TWA).  Short-term exposures or exposures from operating saws indoors can be significantly higher (up to 10 mg/m3).” (OSHA Controlling Silica Exposure in Construction – 2009)

Another less understood, but emerging hazard is engineered nanomaterials. Incredibly small particles are being added to a broad range of construction products to improve performance, but animal toxicity tests indicate a need for closer scrutiny.  There is no evidence yet that engineered nanomaterials have caused harm in exposed workers. However, it is most important that exposures be limited and that precautionary approaches be used to reduce exposure and protect construction workers from the potential hazards of engineered nanomaterials. Nano-size ultrafine titanium dioxide, which can be present in nano-enabled masonry products, has been found to cause inflammation of the lungs and lung cancer in lab animals. The National Institute for Occupational Safety and Health (NIOSH) has determined that ultrafine titanium dioxide should be considered a potential occupational carcinogen. Other engineered nanomaterials that may be present in products used in masonry work could also have the potential to cause harm when inhaled. Cutting nano-enabled concrete roofing tiles containing titanium dioxide without vacuum dust controls can generate excessive amounts of airborne dust that if inhaled by workers could increase the risk of developing respiratory disease (West GH, et al 2016)

OSHA has no specific regulation or Permissible Exposure Limit (PEL) for any engineered nanomaterial. However, NIOSH has a recommended exposure limit (REL) for ultrafine titanium dioxide of 0.3 mg/m3 as a time-weighted average (TWA) concentration for up to 10 hours/day during a 40-hour week. The intent of the REL is to lower the risk to workers of the potential for developing lung cancer.


How Risks are Reduced:

When a vacuum system is used to capture silica, engineered nanomaterials from nano-enabled construction products, and other dust at or very near the source, dust concentrations in the worker’s breathing zone and exposures are reduced.  In some cases, particularly where work is intermittent or in an area with general ventilation, use of dust collectors may be adequate to reduce the need to wear a respirator, and the need for an employer’s respiratory protection program.

For example:  A 2009 study, “Engineering Control Technologies to Reduce Occupational Silica Exposures in Masonry Cutting and Tuckpointing”, found respirable silica levels were reduced by 96% with the use of the vacuum while cutting block.   Average exposure with use of the control was 0.11 mg/m3 or just over the OSHA Permissible Exposure Limit (PEL) of 0.05 mg/m3 and the NIOSH Recommended Exposure Limit (REL) of 0.05 mg/m3.  Respirable silica levels were reduced by 91% when cutting brick with an average exposure of 0.08 mg/m3, which is a significant reduction in exposure but still above the OSHA PEL and NIOSH REL of 0.05 mg/m3.  In situations where engineering controls do not reduce exposures below the exposure limits, additional administrative controls and personal protective equipment like respiratory protection would also need to be used to reduce exposures below those exposure limits.  The results were based on data collected in 2006 using the Bosch saw and an earlier version of the Bosch vacuum described earlier.

NIOSH found similar results in a separate 2007 study, “In Depth Survey of Dust Control Technology for Cutting Concrete Block and Tuckpointing Brick,” which was based on data collected in 2004.  This study found respirable silica exposures were reduced by 95% when cutting block, and noted that dust levels were reduced by maintaining the saw's blade depth to the minimum necessary to make the cut. 

Hilti reports that use of its Dust Removal System reduces dust by as much as 99%, and results in “higher comfort and better protection for the workers.” (To learn more click on: Hilti Dust Solutions Brochure)

A study conducted by CPWR – The Center for Construction Research and Training demonstrated that local exhaust ventilation (LEV) equipped on a hand-held masonry saw was effective in substantially reducing exposures to both respirable dust and titanium dioxide while cutting nano-enabled concrete roofing tiles that contained titanium dioxide. Tiles were cut completely through in a controlled chamber setting and in the absence of vacuum dust controls, excessive amounts of visible dust were generated. When LEV was used, statistically significant reductions in mean concentrations of respirable dust and airborne titanium dioxide were obtained. Reductions in mean exposure concentrations were 95% or greater when LEV was used and the concentrations of airborne titanium dioxide were below the NIOSH REL for both fine (2.4 mg/m3) and ultrafine (0.3 mg/m3) titanium dioxide. (West GH, et al 2016).


Effects on Productivity:

Vacuum dust control systems create a cleaner work environment, and increase workers’ visibility and comfort when engaged in dust producing tasks.  Improved worker visibility and comfort may in turn result in less fatigue for the worker and greater productivity.   Capturing dust at the source may also eliminate or reduce time spent cleaning up the work site and adjacent property (including cars, etc.).

Other items that may impact productivity include the time spent changing vacuum bags, which will depend on the amount of cutting being done and the size of the vacuum bag or hopper, and the time it takes workers to adapt to working with a vacuum hose attached to the tool.


Additional Considerations:

To achieve maximum dust control and exposure reductions, the saw and vacuum system must be maintained and the workers must be trained on the proper use of the equipment.  Use of tools and the tasks performed must also be in compliance with applicable local, state or federal regulations.   Things to consider: 

  • When dust is captured at the source, the risk of exposing other workers, members of the public, adjacent property, cars and building occupants is avoided, which reduces the risk of time consuming disputes and related liability.
  • The vacuum must be located as close to the dust generation as possible to be effective. A hood or shroud is needed to contain the dust so the vacuum can capture it. The shroud must be kept as close to the work surface as is practical to provide adequate dust capture.
  • Not all vacuums and filters are effective in reducing exposures.  The particles that can do the most damage in the lungs are small enough to penetrate the filters found on many shop vacuums. Additionally, some inexpensive shop vacuums pull the dust through the motors, which can destroy the vacuum on very dusty jobs.
  • For dust containing harmful particles like silica or engineered nanomaterials, it is important to use the highest efficiency filters as practical. The best available are called HEPA (High Efficiency Particle Air) filters because they capture 99.97% of 0.3 micron particles (the most penetrating size).It is important to keep in mind that HEPA filters also create a greater pressure drop and decrease in air flow rate because it is more difficult to pull air through these denser filters so capture velocity may be reduced. They also require pre-filters to extend the life of the HEPA filters, which are more expensive than other filters. For operations that generate large amounts of dust, a cyclonic collection unit may be the best solution. Cyclonic collection units spin the particles and drop them into a vacuum bag.  As a result, these units can be used with less expensive vacuum bags and the bags need to be replaced far less frequently because loading of the bags does not cause a pressure drop.  
  • Large electric vacuums commonly require 20 amp electrical circuits in addition to the 20 amp circuit used for the electric masonry saw.  Cords and extensions must be rated for the tool's power requirements, be inspected regularly, and used in combination with ground fault interrupt circuits.
  • Hand-held masonry saws frequently generate sound levels that are greater than 90 decibels, the OSHA Permissible Exposure Limit (PEL), and hazardous. Hearing protection should be worn when using masonry saws unless the manufacturer specifies that the noise level is lower, or an industrial hygienist has conducted noise monitoring and indicated that hearing protection is not required.
  • Hand-held masonry saws frequently weigh more than 20 pounds and the heaviest exceed 30 pounds. Use of these tools will require a strong static effort which can lead to fatigue, pain and musculoskeletal disorders. Operators should take breaks on a regular basis and when fatigued.

Contributors:

Bruce Lippy, PhD, CIH - CPWR - The Center for Construction Research and Training
Michael R. Cooper - Aria Environmental, Inc.
Bill Kojola, MS


Hazards Addressed:

Availability

Hilti DCH 300 and VC 40-U Vacuum
To obtain information, visit DCH 300 and VC 40-U vacuum or contact 1-800-879-8000

Husqvarna K 3000 Vac Electric Power Cutter and compatible Dustcontrol DC 3900c
To obtain information, visit Husqvarna K 3000 and DC 3900c vacuum or contact 1-800-288-5040

Dustcontrol, Inc.
To obtain information, visit Single Phase Dust Extractors or contact 1-910-395-1808 sales@dustcontrolusa.com

NIOSH Workplace Solutions Sheet
The National Institute of Safety and Health (NIOSH) has published a series of “Workplace Solutions”, which are easy-to-understand recommendations from NIOSH research results. Related to this Construction Solution, please find more information on: Reducing Hazardous Dust Exposure When Cutting Fiber-Cement Siding

Makita 14 Angle Cutter 4114 and compatible Dustcontrol DC 3900c
To obtain information, visit Makita angle cutter and http://dustcontrol.com/product/32-dc-3900c-turbo.html or contact 1-714-522-8088

Bosch Abrasive Cut-off Saw 1364 and Bosch Airsweep 13 Gallon Wet/Dry Vacuum with Power Broker
To obtain information, visit Model 1364 Saw and Airsweep vacuum or contact 1-877-267-2499

Return on Investment

To calculate the return on investment (ROI) for your specific application, please visit our Return on Investment Calculator. While a specific ROI example has not been developed for this particular solution, the ROI Calculator provides a useful tool and guidance on how to generate your own on investment analysis.