The Health and Productivity Benefits of Emissions-Based Maintenance
By Ed Rutkowski
NEW ORLEANS, Louisiana (June 3, 2026)—In the age of electric vehicles, diesel engines may seem a quaint technology. But as Deon Swanepoel explained yesterday at an AIHA Connect educational session, diesel engines are still prevalent in underground mining, partly because they present fewer fire and explosion hazards than alternative technologies. For example, unlike gasoline engines, diesel engines use compression, not ignition, in their combustion process. Their lack of spark makes them a safer choice for use in mines, where explosive gases can accumulate. That heightened risk of explosion also precludes wide adoption of electric vehicles in mines due to the potentially catastrophic consequences of a lithium-ion battery experiencing thermal runaway. And diesel has the advantage of efficiency: more work can be done on 50 liters of diesel than on the equivalent amount of gasoline, Swanepoel said.
But as OEHS professionals are well aware, exposure to diesel engine exhaust can have serious health effects. Early attempts to protect workers focused on acute effects such as headaches, dizziness, and irritation of the eyes, nose, and throat. Growing evidence that diesel exhaust causes cancer led the International Agency for Research on Cancer, in 1998, to classify it as probably carcinogenic. Then, in 2012, IARC revised its determination and upgraded diesel exhaust to a known human carcinogen (PDF).
Efforts to improve production while controlling exposures to diesel exhaust gave rise to emissions-based maintenance, or EBM, which was the focus of Swanepoel’s presentation. Deteriorating engines produce more emissions, leading to disproportionate effects on workers. The idea behind EBM is to monitor key indicators of engine performance and initiate maintenance before emissions spike. For example, high levels of particulate matter in exhaust indicate incomplete combustion, Swanepoel said. Similarly, high carbon monoxide suggests the engine is burning too much fuel, while high nitrogen indicates an issue with engine timing. These insights can prompt maintenance personnel to initiate fixes.
Although EBM has been around for decades, Swanepoel believes it is still under-utilized—especially because it saves money while helping protect workers. “EBM is associated with quite a lot of production gains,” he said, including lower emissions, longer service life of diesel particulate filters, less fuel consumption, improved fleet management, and reduced dilution ventilation. A common rule of thumb, Swanepoel said, is that every dollar spent on preventive maintenance yields a return of $1.50 in cost avoidance.
The benefits of EBM became clear to Swanepoel, a consultant based in South Africa, when he reviewed a decade’s worth of vehicle maintenance records for a coal mine. The data spanned the years 2012 through 2022, with implementation of EBM in 2017, allowing Swanepoel to measure its impact. He found that EBM likely led to two fewer corrective maintenance events per vehicle per year, and one less breakdown per vehicle per year. These contributions to the bottom line, combined with the health benefits of better controlling worker exposures to diesel engine exhaust, make EBM an attractive proposition for managers focused on financial performance.
To be sure, implementation of EBM has challenges. The early stages will likely cause disruptions, so support from management is paramount. Worker buy-in is just as crucial; maintenance personnel, for example, may be reluctant to remove working vehicles from service. Collaboration among departments is needed to collect data, develop target values for various indicators of engine performance, and track engine health across the company’s fleet. Swanepoel closed by suggesting that OEHS professionals are the best choice to coordinate EBM’s disparate elements.
Eventually, improvements in battery technology may render diesel engines obsolete. Until then, OEHS professionals will need to grapple with the effects of diesel engine exhaust and diesel particulate matter. “If you want to eliminate DPM, stop having internal combustion engines—problem solved,” Swanepoel said. “We aren’t there yet.”
Ed Rutkowski is editor in chief of The Synergist.