Fowler Associates Labs

Static Shocks In Supermarkets
Grocery Stores - Malls - etc.
July 1, 2010
Steve Fowler Fowler Associates, Inc.

"OK, this may sound minor and not even just a TN situation, but I need to know if anyone has advice on how to prevent static electricity from getting me every time I touch metal. I came from FL, where humidity is high and didn't have a problem. Now, with the cooler weather and low humidity, I am almost in pain just going to the grocery store picking up canned goods! Forget about opening the milk case. I did hear that putting a dryer sheet in your pocket may help. Is this true? Any suggestions would be welcome. It hurts!!"

This is typical of the comments about static electric shocks. Look over the links on the bottom of this page for more information on the problem.

The problem is simple:

1. The problem is Triboelectric static generation

2. The static generation is from the insulative wheels rolling on an insulative floor. Typically a new store with new carts cause the most problems.

3. The electrostatic charge is accumulated on the wheels inducing a high electric potential on the cart. If there is a platic handle on the cart, this potential is induced on the person. If there is no plastic hanle or if the person is touching the cart, the high potential is conducted to the person. In any case the person and the cart rise to high electric potential.

4. This potential causes a painful or annoying spark discharge when the person touches the metal of the food racks or the product such as canned vegitables. It is like walking across a carpet and touching a metal door knob. ZAP!

Lack of grounding of the store and racks is not the problem. In fact it is the grounding of the metal in the store that makes the energy of the discharge higher. It has a very low resistive path to ground of the discharge from the person.

This problem can be reduced by the cart manufacturer by making the wheels conductive with carbon loading or conductive fibers. Many manufacturers either do not know this or do not want to add the costs.

Some stores have fairly successfully made attempts to solve the problem by adding drag wires on the carts.click here for the article

These wires work by the principle of passive ionization - described below. If the store where you are shopping does not have the drag wires, you can add your own using an aligator clip.

One solution which has had some very good success is the use of conductive threads in a bracelet form much like a "Friendship Bracelet". This bracelet's fine conductive threads perform what is called Corona Ionization. Corona ionization causes ions to flow from the charged person to ground (treadmill) and discharge the person so gently that they do not know it is happening.

These threads have very small points which allow ions to flow freely as soon as the person reaches a high potential from the triboelectric charging from the treadmill.

This picture shows how the bracelets are worn. As the person walks and reaches for the a can of vegetables she is discharged gently by the passive ionization bracelet.

Click on the following video for a more detailed view. Bracelet Video

How to properly use the static bracelet
click here

The following video shows how the bracelet works by Passive Corona Ionization. Notice the Van De Graff generator charges and arcs repeatedly until the bracelet is held close to it. The arcs cease during the time the bracelet is near the dome. This is because it is drawing ions from the Van de Graff by corona ionization unfelt by the wearer. It seems like magic but in fact it is real physics.

Van de Graff and Static Friendship Bracelet
click here

The bracelet can be fabricated using Static String** or any highly conductive threads.

Anyone can make such a bracelet if they have highly conductive string such as from Static Stop

To place an order for a bracelet, please contact Anti Static Bracelets & Accessories at: www.antistaticbracelets.com

http://www.city-data.com/forum/other-topics/469890-static-electricity-moved-tn-forum.html
http://www.associatedcontent.com/article/239022/always_getting_zapped_by_static_electricity.html?cat=5
http://www.esdjournal.com/articles/Shoppingcarts.htm
http://patricksinventionideas.blogspot.com/2007/08/no-0031-grocery-cart-static-generator.html
http://consumerist.com/2009/05/are-walmarts-new-shopping-carts-shocking-customers.html
http://www.votemenot.co.nz/thread/232954/why-do-i-get-electric-shocks-off-shop-shelving/
http://www.planetfeedback.com/index.php?level2=blog_viewpost&topic_id=324803&reply_id=283574
http://www.answerbag.com/q_view/1078499
http://www.eons.com/groups/topic/572454-Diabetes-and-getting-shocked\
http://www.protectagainstemf.com/page/391770231
http://forums.randi.org/showthread.php?t=74362
http://www.healthboards.com/boards/archive/index.php/t-118770.html

*Static Friendship Bracelet" is a trademark of the ESD Journal and Fowler Associates, Inc. Patent Pending

** Static String is a trademark of Stop Static