The Quiet EV Charging Emissions You Didn

• EV fast chargers kick up harmful particles that can be over twice the urban background pollution level.
• The chargers’ cooling fans stir up fine particles created by brake and tire wear, as well as dirt and dust from other sources.
• Standing a few feet away from a fast charger that’s in use limits the exposure to these fine particles.

Electric vehicles may be completely tailpipe emissions-free, but they still pollute the air with particles generated by tire and brake wear. And apparently, they’re responsible for one more source of pollution, which occurs when you plug them into a DC fast charger.

Scientists measured the air quality around a rapid charger while it’s topping up an EV and found that it goes down. A team at UCLA, led by environmental health professor Yifang Zhu, found that the air around EV fast chargers in use had twice the amount of harmful fine particles typically found in an urban environment.

Zhu pointed out that “There’s no healthy amount of fine particulate matter to breathe, and the amount around fast chargers for electric vehicles is about twice as high as background levels of PM 2.5 (fine particulate matter). We tested 50 fast chargers across LA and found higher particle levels near their power cabinets, with even higher levels of metal tracers from brake and tire particles.”

Photo by: UCLA

But the particles aren’t coming from the chargers themselves. They are likely being stirred up by vortexes created by the chargers’ powerful cooling fans, which lift the particulate matter settled on the ground and inside the chargers. The sources of the particles are multiple; it’s mainly the result of brake and tire wear, but it’s also just dirt and dust that gets mixed.

The UCLA team found the level of PM 2.5 particles around chargers ranged from 7.3 to 39 micrograms per cubic meter, while the typical range measured in urban settings in California was between 3.6 and 12.4 micrograms per cubic meter. The highest levels were observed around chargers in Los Angeles County, which also has the largest concentration of DC fast chargers. It has 1,938 units in operation out of a total of 9,900 across all of California.

Zhu noted that “In Los Angeles, the urban background PM 2.5 is 7 to 8 micrograms per cubic meter. Urban traffic sites in L.A., like freeways or busy intersections, range around 10 to 11. We measured a few gas stations at about 12. Fast chargers average 15, and sometimes peak as high as 200.”

He concluded that it’s best not to stay directly near a DC fast charger while it’s in operation. “We measured at different distances from the chargers,” Zhu explained, adding that “the high measurements [15-200] were taken at the chargers’ power cabinets. Fortunately, a few meters away, the concentrations drop quite a bit. A few hundred meters away, there’s no noticeable difference compared to background levels of pollution.”

If you’ve ever charged your EV using any DC fast charger, you know how loud the cooling fans can get. Some units even start emitting a smell not long after the fans start spinning. So while you can’t see these microscopic particles, in many cases you can smell them, and that’s your cue to take a few steps back while your car is charging.

Mind you, if you’re DC fast charging by the side of a busy freeway where dozens of diesel trucks are driving past emitting fresh particles, along with hundreds of other cars, the air quality isn’t great, either. 

Why do you want to avoid inhaling these PM 2.5 particles? Well, because they can very easily enter your body, it’s very hard to get rid of them, and they can cause all sorts of health problems. UCLA Fielding’s Department of Environmental Health Sciences Michael Jerrett said, “For anyone, exposure to fine particles can contribute to health issues, and for those with existing conditions or heightened sensitivity, the risks are even greater. Because these particles are so small, they can travel deep into your lungs and even enter your bloodstream—potentially leading to serious problems like heart or lung disease.”

If you have to stay near your EV while it’s fast-charging, you can use a mask with a filter designed to keep PM 2.5 particles out of your airways. Make sure you get a good-quality mask that seals well around your face. Some have been proven to filter up to 95% of airborne particles, so make sure to get a good one that has actually undergone testing.

According to data provided in the study, which used a very accurate holographic particle monitoring device, just taking a few steps back from the charger greatly limits your exposure to all of this airborne microscopic nastiness, making it more important to go inside to get a bite or a coffee while waiting for the car to charge.

Ultimately, the lack of tailpipe emissions on EVs makes them a better environmental choice than anything gas-powered, and the research on this is extremely definitive. While these kinds of story may be used as anti-EV fodder elsewhere, here’s a better explanation: standing right next to the DC fast-charger isn’t great in terms of environmental health. Stand back, and then enjoy emissions-free driving when you’re done.