Summary 

Construction workers are 

exposed to hazardous dust 

when using jackhammers 

to break concrete pavement. NIOSH found that 

exposures could be reduced by using a waterspray attachment. 

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

Figure 1. The water spray attachment, showing the method used to attach 

the nozzle to the tool.

NIOSH Study 

NIOSH studied a water-spray attachment (Figure 1) to suppress dust 

created during concrete pavement 

breaking with jackhammers [Echt et 

al. 2003]. This low-flow, water-spray 

control reduced dust exposures by 

70%–90%.

Description of

Exposure 

Breathing dust that contains crystalline silica can lead to silicosis, a deadly lung disease. Exposure to crystalline silica has also been linked to 

lung cancer, kidney disease, reduced 

lung function, and other disorders 

[NIOSH 2002]. No effective treatment exists for silicosis, but it can be 

prevented by controlling worker exposure to dust containing crystalline 

silica. 

Workers in the construction industry 

may breathe dust that contains crystalline silica during many tasks including grinding concrete, cutting brick 

and block, tuckpointing masonry, or 

using a jackhammer to break concrete. A study to measure exposures 

found that jackhammer operators who 

break concrete were exposed to about 

6 times the NIOSH recommended 

exposure limit (REL) [Valiante et al. 

2004]. NIOSH evaluated the use of 

jackhammers for breaking concrete 

pavement and examined engineering 

controls to see whether they reduce 

worker exposures to dust [Echt et al. 

2003]. 

Water Spray Control of Hazardous

Dust When Breaking Concrete with a

Jackhammer
Water-Spray Control 

The water-spray attachment was made by a contractor 

who participated in the NIOSH study (Mt. Hope Rock 

Products, Inc., Wharton, NJ, a division of Tilcon New 

York, Inc., West Nyack, NY). There is continuing development of water-spray controls similar to the one used in 

the NIOSH study. For example, The New Jersey Laborers Health and Safety Fund (NJLHSF) has also developed 

a simple durable, low-cost water-spray attachment for use 

on a jackhammer (www.njlaborers.org/index.php3). The 

NJLHSF version of a water-spray attachment used the 

control described in this document as a starting point. A 

detailed description of the NJLHSF water-spray attachment and estimated cost can be found at their Web site 

(www.njlaborers.com/health/jackhammer.php3).

NIOSH is not aware at this time of off-the-shelf, commercially available retrofit kits or jackhammers that 

come with built-in water spray units. However, it is relatively simple to build a water spray control for a jackhammer using the diagram in Figure 2 and the parts and 

instructions below: 

 Water-spray nozzle: Use a solid-cone, furnace-spray 

water nozzle with an 80-degree spray angle (Type B, 

11.00 GPH, 80°, Delavan Inc. Fuel Metering Products, Bamberg, SC www.delavaninc.com). Mount the 

nozzle in a bracket welded on the end of the jackhammer. The spray angle (the angle included between the 

sides of the cone formed by the water discharged by 

the nozzle) and the spray pattern are two critical design parameters required to match the performance of 

the tested device. Spray nozzles make several spray 

patterns such as hollow cone, full cone, and flat spray. 

This control used a solid cone nozzle.

 Water flow rate: The nozzle used in the NIOSH study 

delivered about 350 milliliters (11.8 ounces) of water per minute. This flow rate is the third critical design parameter for performance of this control. It is 

effective in reducing dust and it did not add a lot of 

water to the work surface or significantly wet workers’ clothing or shoes. Higher flow rates may not greatly increase dust control, and lower flow rates may reduce performance.

 Bracket: Use a bracket for mounting the water-spray 

nozzle on the jackhammer. Mounting the nozzle above 

the end of the jackhammer will prevent the nozzle 

from striking the pavement. 

 Water-supply lines: Connect the nozzle by flexible 

16 pounds-per-square-inch (psi), 3/8-inch-diameter hydraulic line to a quarter-turn valve mounted 

near the operator’s hand position for turning the water on or off. A 3/8-inch-diameter air hose connects 

the valve to a 60-gallon water tank (pressurized to 

22 psi) mounted on the air-compressor trailer (Figure 

3). Control the pressure in the tank with a regulator. 

 Water source: Use a water tank or a direct connection to a local water supply such as a water main. If 

a tank is used, water can be supplied to the attachment by pressurizing the tank or pumping water from 

the tank. If a pressurized tank is used, a compressor 

is needed to pressurize the tank, a regulator to control the pressure, and a pressure relief valve to guard 

against the tank bursting. Rust from a steel tank may 

clog the spray nozzle. However, a plastic water tank 

can be used with a battery-powered water pump instead of a steel pressurized tank. The larger the tank, 

the less it will have to be refilled. A 50-gallon tank 

will easily supply one jackhammer water-spray control used constantly for a full 8-hour shift. A trailer 

or hand truck may be necessary for moving the tank 

around the worksite. 

Controlling Dust Exposures 

The results of the NIOSH study showed that the control devices may reduce exposure to dust for jackhammer operators and other workers near the work area. 

Employers and jackhammer operators should take the following steps to reduce worker exposure to hazardous dust: 

Site Set-Up 

 Develop a site-specific safety and health plan for all 

job sites where jackhammers are used that considers 

engineering controls, personal protective equipment, 

and work practices. 

Figure 2. Diagram of water-spray control used in 

NIOSH study
 Minimize the number of workers in the construction 

area where jackhammers are used. 

 Post signs to warn workers about the hazard and 

to inform them of required protective equipment. 

Workers should also be cautioned about icing, slips, 

and falls (particularly if they make a mud hole), and 

about ground faults for any electrical system in use.

 During jackhammer use, perform air monitoring of 

respirable crystalline silica exposures to make sure 

the engineering controls are working and to determine whether workers need respiratory protection.

 Make medical examinations available to all workers 

exposed to crystalline silica. 

Engineering Controls 

 Equip jackhammers with dust-reduction control devices such as the water-spray attachment described 

in this report. When a water-spray attachment cannot be used (for example, on the upper floor inside 

an occupied building), use other control measures 

such as a vacuum or other local exhaust ventilation 

(LEV) device [Echt et al. 2003]. Spraying the work 

area with a garden hose is not an appropriate replacement for the water-spray control. 

 Train workers in the proper use and maintenance of 

the dust-reduction device. Make sure that the control is working properly and test the water flow rate 

before and after each shift; a watch with a second 

hand and a kitchen measuring cup could be used for 

this task. An 8-ounce cup should fill in about 40 seconds.

Personal Hygiene and Protective 

Clothing 

 Wash hands and face before eating, drinking, or smoking. Do not eat, drink, or use tobacco products in the 

work area. 

 Change into disposable or washable work clothes 

at the worksite. If possible, shower and change into 

clean clothes before leaving the worksite. If it is not 

possible to shower or change into clean clothes, use a 

vacuum to remove dust from clothes.

 Park cars where they will not be contaminated with 

silica dust.

 Do not remove dust from the work area by blowing 

with compressed air or dry sweeping. Also, do not 

blow dust from clothing or skin with compressed air. 

Protective Equipment 

 Use hearing and eye protection devices. When waterspray attachments are used with jackhammers, waterproof personal protective equipment may be necessary. 

 Use respiratory protection when needed. The controls cited in this report may greatly reduce worker exposure to dust; however, respirators may still be 

necessary to reduce exposure to crystalline silica below the NIOSH REL of 50μg/m3

. It may be possible 

to use less restrictive respirators such as a disposable 

N–95 filtering facepiece since the amount of hazardous dust is decreased by the controls. The respirators are less cumbersome and cost less than the respirators typically required for jackhammer operators. 

Employers should follow the Occupational Safety 

and Health Administration (OSHA) Respiratory Protection Program (29 CFR 1910.134). 

Acknowledgments 

The principal contributor to this publication was Alan 

Echt of the Division of Applied Research and Technology, 

National Institute for Occupational Safety and Health. 

John J. Whalen, under a NIOSH contract, served as lead 

writer/editor. This research was conducted in cooperation with the New Jersey Silica Partnership. 

References 

Echt A, Seiber K, Jones E, Schill D, Lefkowitz, Sugar J, 

Hoffner K [2003]. Control of respirable dust and crys- Control of respirable dust and crystalline silica from breaking concrete with a jackhammer. Appl Occup Environ Hyg 18:491–495. 

Figure 3. Water tank mounted on compressor trailer
For More Information

Furthermore, NIOSH is not responsible for the content of 

these Web sites.

This document is in the public domain and may be freely 

copied or reprinted. NIOSH encourages all readers of the 

Workplace Solutions to make them available to all interested employers and workers.

As part of the Centers for Disease Control and Prevention, 

NIOSH is the Federal agency responsible for conducting research and making recommendations for preventing work-related illnesses and injuries. All Workplace Solutions are based 

on research studies that show how worker exposures to hazardous agents or activities can be significantly reduced.

Water Spray Control of Hazardous Dust When 

Breaking Concrete with a Jackhammer

DHHS (NIOSH) Publication No. 2008–127

The information in this document is based on NIOSH field 

studies. More information about silica hazards and controls is 

available on the NIOSH Web site at www.cdc.gov/niosh/topics/silica/default.html. 

To receive copies of the NIOSH field study reports that 

formed the basis of this document or to obtain information 

about other occupational safety and health topics, contact 

NIOSH at 

Telephone: 1–800–CDC–INFO (1–800–232–4636)

TTY: 1–888–232–6348  E-mail: cdcinfo@cdc.gov

or visit the NIOSH Web site at www.cdc.gov/niosh

For a monthly update on news at NIOSH, subscribe to 

NIOSH eNews by visiting www.cdc.gov/niosh/eNews.

Mention of any company or product does not constitute endorsement by NIOSH. In addition, citations to Web sites external to NIOSH do not constitute NIOSH endorsement of 

the sponsoring organizations or their programs or products. 

Safer • Healthier • PeopleTM May 2008

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

4676 Columbia Parkway

Cincinnati, OH 45226–1998

NIOSH [2002]. NIOSH hazard review: health effects 

of occupational exposure to respirable crystalline 

silica. Cincinnati, OH: U.S. Department of Health 

and Human Services, Centers for Disease Control 

and Prevention, National Institute for Occupational 

Safety and Health, DHHS (NIOSH) Publication No. 

2002–129. 

Valiante DJ, Schill DP, Rosenman KD, Socie E [2004]. 

Highway repair: a new silicosis threat. Am J Public 

Health 94(5):876–880.