TECHNICAL FEATURE Engineering Controls For Occupational Health Risk Administration BY KANG CHEN, PH.D., MEMBER ASHRAE Over the past decades, most research in occupational health risk control has emphasized the use of engineering controls in the hierarchy of controls (HoC). Although engineering controls is a mature methodology that has been widely adopted by occupational health and indoor environmental quality (IEQ) professionals to eliminate or mitigate the occupational exposure risk, the major issue is that the pertinent literature is scattered, with most being case studies. The author is not aware of any systematic attempts made to present a comprehensive life-cycle view of engineering controls. That fact motivated this research aimed to facilitate a better understanding and proper application of engineering controls as a countermeasure for occupational health risk administration. Overview of Engineering Controls in the Hierarchy of Controls While occupational health and IEQ experts usually advocate giving preference to the intervention strategies on the top layers of the hierarchy of controls (HoC)- namely elimination and substitution, it is difficult to implement those strategies in many cases because most of the time they are technically infeasible or economically unaffordable-or just less effective. In this way, engineering controls might be the most promising solution in the pyramid of the HoC once it is properly Kang Chen, Ph.D. is an EHS and facility leader at PetroChina Shanghai Advanced Materials Research Institute and a doctoral research and dissertation committee member at Capitol Technology University. 42 ASHRAE JOURNAL ashrae.org O CTO B ER 2023 designed and effectively validated. Figure 1 illustrates the FIGURE 1 Engineering controls in the hierarchy of controls (HoC). Elimination Substitution Engineering Controls Administrative Controls Personal Protective Equipment Hierarchy of Controls (HoC) Acceptable Risk Temperatures Noise Extreme Vibration Radiation Unacceptable Riskhttp://www.ashrae.org