Static shock can be irritating to downright painful. That’s because when you get shocked from what’s commonly called “static electricity” it’s really high-voltage electricity. Depending on conditions, it can actually reach a potential of several thousand volts. Furthermore, the drier the air, the greater your chances are of this happening.
What Causes Static Shock?
Static electricity forms whenever the quantities of positive and negative electrical charges in something aren’t perfectly equal. Normally the positives cancel out the negatives, and everything behaves electrically neutral.
But, if two insulators of different materials contact each other, then the electrical charges of the material transfer between the surfaces. One surface ends up with more negative charges than positive, resulting in a negative charge imbalance. The other surface has fewer negative charges than positive, resulting in a positive charge imbalance. Both surfaces are electrically charged, and there’s a high potential voltage between them.
As long as those two surfaces stay together, their electrical charges cancel each other out. But, if you separate them, you also separate their polarities. A positive charge stays with one surface, while a negative charge stays with the other. The potential voltage between the two surfaces now rises dramatically. If you bring the two surfaces back together, at some point, the opposing polarities jump the gap and rejoin, producing a high-voltage spark.
From our little science lesson, you can see why in dry weather you can get shocked when you step out of the vehicle and close the door. Your body becomes electrically charged from your clothing (an insulator) contacting the seats and seat-backs (a different insulator).
When you step out, you’re taking just one polarity of charge along with you, while the seat keeps the opposite one. At the same time, the seat is causing the entire vehicle to become electrically charged due to a process called “Faraday’s Ice Pail Effect.” The potential voltage between you and the vehicle now surges up to 10,000 or even 20,000 volts. If you’re wearing shoes, especially those with rubber soles, the charge has no chance to leak to ground. When you reach out to close the door, which is grounded to the vehicle, the opposite polarities rejoin at your finger, and you get shocked.
How to Avoid Getting Shocked
Now that you kow what causes staic shock, here are some tips to help you avoid it:
• Avoid wearing clothing that contribute to static shock. Clothing made from wool or from synthetic materials such as nylon, polyester, or plastic, put a greater electrical charge on your body than clothing made from cotton or other materials. A 1998 study done in the UK recorded peak body voltages of 21,000 volts when wearing nylon clothing, 9,000 volts for wool clothing, and 7,000 volts for cotton clothing. Also, consider choosing leather upholstery instead of fabric. Fabric upholstery creates a greater charge imbalance than leather does.
• Shoe soles create a charge imbalance and work as insulators as well. To avoid getting shocked, don’t wear rubbersoled shoes. They create a significant charge imbalance, and when you step out of the vehicle, the insulating properties of rubber keep the charge from leaking to ground. Try wearing thin, leather-soled shoes instead.
American Honda Motor Company 2019