A new study from the American Chemical Society provides a reminder that tailpipes aren't the only source of harmful vehicle emissions.

The study suggests that wiper fluid could be a significant source of emissions, one that will become a bigger part of the vehicle fleet's overall carbon footprint as EV adoption increases.

Hyundai wiper setting alert

Hyundai wiper setting alert

That's because wiper fluid produces volatile organic compounds (VOCs), which can easily vaporize and pollute the atmosphere. Based on an inventory of manufacturer statistics in the UK, researchers found that car care products—including wiper fluid—could be a bigger source of VOCs than vehicle exhaust.

The potential emissions impact of wiper fluid had never been scientifically tested, though, so researchers measured it from cars on real-world roads. Outside of water, alcohols are a main ingredients in wiper fluid, and researchers found that emissions of two alcohols—ethanol and methanol—contained almost double the VOCs of exhaust emissions.

Michelin Stealth Wiper Blades

Michelin Stealth Wiper Blades

This is just one of a series of sources from vehicles that hadn't previously been fully assessed—except, perhaps, for within California, where there are already summer and winter mixes of wiper fluid for this very reason. Tires and brakes are other such sources, and several studies have now assessed microplastic pollution from tires to be a serious global issue. This requires some innovative solutions—such as a special device that picks up tire dust proposed by UK inventors. 

From a point-source standpoint, vehicles have become so much cleaner that the use of household cleaners may emit more VOCs than a vehicle, so when you don't need washer fluid, you're truly doing something good for the environment in using plain water. Even that won't completely solve air-pollution issues in places like Los Angeles, though, one study has argued, due to emissions from natural sources.