Engineering Controls Program
The NIOSH Engineering Controls Program seeks to protect workers by engineering interventions that can eliminate hazards or make work safer.
New Engineering Control for 3D Printers
Although 3D printing is still a new and rapidly growing field, some studies show that workers are experiencing exposures to emissions from 3D printing processes and suffering health effects from the exposures. NIOSH developed an effective engineering control solution to help protect workers from potentially harmful exposures. Researchers evaluated the engineering solutions using 20 3D printers operating at the same time in a simulated workspace. The number of particles measured in the room air was more than 20 times the background levels without the engineering controls but remained at or below background levels with the engineering controls in use. NIOSH researchers uploaded instructions and part files for the engineering control solution to make the solution publicly available. Users can freely download at the National Institutes of Health (NIH) 3D print exchange under model #: 015467.
Engineering controls protect workers by removing or reducing hazardous conditions such as harmful dust or dangerous noise levels. Well-designed engineering controls can be highly effective in protecting workers through solutions like machine guards or local exhaust ventilation (LEV). The mission of the NIOSH Engineering Controls Program is to eliminate occupational diseases, injuries, and fatalities through a focused program of research and prevention across all industries and sectors. Traditionally, a hierarchy of controls approach has been an important tool for determining how to implement feasible and effective control solutions.
NIOSH engineering control efforts include the following activities:
- Plan and conduct research on engineering control technology to prevent worker exposures to hazards.
- Promote the application of effective engineering control technology for safeguarding worker safety and health.
- Provide expertise in formulating effective and credible workplace standards.
- Provide consultation in the application of effective control solutions and techniques for hazard prevention.
- Promote the application of Prevention through Design (PtD) as one of the best ways to prevent and control occupational injuries, illnesses, and fatalities by “designing out” or minimizing hazards and risks using engineering control solutions.
The Engineering Controls Program protects workers by removing or reducing occupational hazards. This is done by researching, developing, and promoting engineering technologies that block, filter, or otherwise reduce hazards. The Program works closely with the NIOSH Program Portfolio, including sectors and cross-sectors. Ten sector programs represent industrial sectors, and seven cross-sector programs are organized around health and safety outcomes. Engineering Controls is one of numerous core and specialty programs that represent core activities, mandates, special emphasis areas, and methodological approaches. The sector programs intersect with cross-sector programs in a matrix-like fashion, with relevant core and specialty programs playing a supporting role.
This approach allows multiple programs to work towards accomplishing the shared research goals in the NIOSH Strategic Plan. The Engineering Controls Program contributes to several goals for reducing hazardous exposures, including:
- Hearing loss prevention in construction, manufacturing, mining, oil and gas extraction, and services
- Airborne contaminants like crystalline silica in mining, oil and gas extraction, and construction
- Hazardous drugs and surgical smoke, as well as infectious diseases in the healthcare and social assistance sector.
- Drilling fluids in the oil and gas extraction sector
- Pesticides, herbicides, and organic dusts in the agriculture industry.
- Welding fumes in manufacturing and construction
- Nanomaterials and other advanced materials in manufacturing and construction
Program Performance One-pager
The Engineering Control Program Performance One-Pager offers a snapshot of the Program’s priorities, strategies, recent accomplishments, and upcoming work.
Silicosis outbreaks have occurred recently among workers who interact with engineered stone countertops. Silicosis is a preventable lung disease caused by inhaling respirable crystalline silica. Many engineered stones contain greater than 90% of crystalline silica by mass. This high percentage of silica increases the risk to workers who inhale dust created during its manufacturing, fabrication, and installation. NIOSH researchers recently identified and evaluated two engineering control measures to successfully reduce workers’ exposure to silica dust.
A common way to reduce dust is to wet the work area with sprays of water. However, NIOSH researchers found that the wetting methods in use were ineffective. By adding a sheet-water-wetting method, NIOSH researchers were able to suppress dust formation. Worker exposures reduced to levels below the permissible exposure limit set by the Occupational Safety and Health Administration (OSHA). Researchers also investigated a second engineering control method using ventilation and air filtration. NIOSH field investigations found that using a mobile dust control booth can reduce workers’ exposure by nearly 80%.
- Hazard Alert jointly issued by OSHA and NIOSH on Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation
- Report: Evaluation of Wetting Methods for Grinding Stone Countertop
- Report: Evaluation of a Mobile Dust Control Booth for Stone Countertop Grinding
From 2007 to 2014, the Transportation Security Administration (TSA) partnered with NIOSH to reduce the risk of musculoskeletal disorders (MSDs) in approximately 45,000 baggage screeners in the United States. Lifting heavy weights repetitively has been identified as one of the main risk factors for MSDs. NIOSH tested a vacuum lifting assist system and an automatic baggage moving system and found both were effective in reducing stress on the body.
NIOSH was requested to provide technical assistance to nine federalized airports (CAK, CLE, CVG, DEN, EWR, IND, LEX, OKC and PAH). After receiving NIOSH’s technical assistance, the MSD rate at these airports lowered to an average less than 1.5% (after 2011) from about 6% at the beginning of the collaboration (2008). Their MSD rates continued to decline as TSA implemented more engineering controls. As a result of the research collaboration, the Indianapolis international airport installed 16 units of a vacuum lifting assist system in their newly designed baggage screening rooms. Additionally, the researchers published the engineering controls tested in this partnership to provide the airline industry with potential methods for reducing the risk of MSDs in about 180,000 airport baggage handlers in the United States.
- NIOSH Workplace Solutions: Reducing Musculoskeletal Disorders among Airport Baggage Screeners and Handlers
- In-Depth Survey Report: Bag Handling Assist Controls for Airport Screening Processes
- NIOSH Science Blog: Vacuum Lifting System to Reduce Spinal Load During Airline Baggage Handling
New and advanced manufacturing technologies require new approaches to protect workers. This includes the relatively new world of Nanotechnology, or the manipulation of matter on a near-atomic scale to produce new structures, materials, and devices. In 2013, NIOSH researchers from the Engineering Controls program and Nanotechnology Research Center published the document, Current Strategies for Engineering Controls in Nanomaterial Production and Downstream Handling Processes. This document was the first to provide specific ways to control exposures in many processes that result in occupational exposures.
In 2018, NIOSH published multiple short information sheets with visuals and schematics of engineering control approaches for nanomaterials. Nanoparticles are extremely small particles (having dimensions between 1 and 100 nanometers) ) designed to have certain new or unique characteristics, like strength, elasticity, or reactivity. These new properties make advanced materials and products possible. The documents include information on protecting workers during nanomaterial reactor operations, protecting workers during the handling of nanomaterials, and protecting workers during intermediate and downstream processing of nanomaterials. In 2020, NIOSH researchers published a summary of 11 worksite evaluations. These include exposure assessment and engineering control recommendations for fume hoods, cleanrooms, and enclosed processes to protect workers from nanomaterials.
Work exposures to silica dust can cause serious diseases like silicosis and lung cancer. In June 2016, the Occupational Safety and Health Administration (OSHA) published a new rule on occupational exposure to respirable crystalline silica. When OSHA first proposed the rule, based on a long history of research on the health effects of silica, NIOSH researchers provided testimony at public hearings. Researchers also shared their extensive efforts to develop recommendations and controls for preventing worker exposure to silica at these hearings. NIOSH researchers have studied the use of engineering controls for grinding concrete, sandblasting, rock drilling, hydraulic fracturing (fracking), concrete floor polishing, cutting fiber cement siding, tuckpointing, and asphalt milling.
NIOSH research on silica in the construction industry played a significant role in developing Table 1 of OSHA’s rule “Exposure Control Methods for Selected Construction Operations.” This table directs construction employers to use specific engineering controls when workers are using a piece of equipment or completing a task.
In 2022, NIOSH researchers published the paper, Engineering Controls for Respirable Crystalline Silica Hazards. It summarizes the history of engineering control-related silica investigations by NIOSH. NIOSH has also promoted the prevention of silicosis through model partnerships and cooperative agreements with government, industry, labor, and academia. Exposure limits to protect workers only work if there are valid and feasible measurement techniques in place. NIOSH research has shown that the exposure limits in the current OSHA standard meet these criteria.
From 2003 to 2016, NIOSH engineers worked collaboratively with a National Silica/Asphalt Milling Machine Partnership. They tested engineering controls designed to reduce respirable crystalline silica exposure during asphalt pavement milling in highway construction. As a result of the collaborative research, NIOSH published a Best Practices document that was a keystone achievement of the multi-year effort. Labor, industry, and government representatives reached a voluntary agreement that placed silica dust controls on all new milling machines sold in the U.S. since January 1, 2017. The established controls keep silica hazards to levels below occupational exposure limits. Two manufacturers, representing 80% of the U.S. market, were so accepting and committed to the NIOSH best practices that they began installing silica dust controls in 2014, three years ahead of the deadline. As of 2020, approximately 45% of asphalt milling machines in the U.S. are fitted with engineering controls.