Dangerous Batteries?

Summary: I think I burned a hole through my skin from leaky AA alkaline batteries. Details follow:

In the picture, you can see three colors on the pH paper. The light green at the top indicates that baking soda has slightly basic pH 8 of. The light orange is the color of the paper itself, and the dark brown indicates that the moisture in the battery compartment had a very strong alkali pH of 13 to 14.

Batteries, batteries . . they are everywhere! I need to write about my second hazardous battery instance in as many months. The first incident occurred when I was recharging AA batteries in a charger recently purchased from Radioshack. Fortunately, I was only a few feet away from it, when I smelled the melting plastic and was able to unplug the overheated beast. The charger and batteries were permanently denied access to any electrical connections in the house.

The second incident occurred Tuesday night as I was futzing with the Rayovac batteries from the boys’ Sharper Image LED lanterns we received as a gift from grandma and use for nighttime stories. I saw moisture inside the battery compartment and thought that with curious children, somehow water had made its way inside. Well, I wiped some of the liquid with toilet paper and started feeling a burning sensation on my finger – same feeling when you get lemon juice or salt in an open wound. So I quickly washed the area and felt a sliminess - you know, the same sliminess when you are using bleach and it gets on your hands. I think that has something to do with dissolving skin cells, but I am not sure. I suspiciously went back to the battery compartment, held it exactly as I had before, and in seconds, ssstiiiingggghhh. Off to the sink again, washing, trying to respond to Sally’s “what happened?” without going into detail or getting the kids engaged into something besides bedtime stories.

I looked closely at my finger to find a red spot, yes an open wound, very small, but also very new. Could these AA batteries be leaking acid strong enough to burn through skin? No, impossible! Well improbable, I thought, but I had some evidence. If it is battery acid, then the liquid should fizz if I put a base on it. This is the same type of reaction my students gets when they combine vinegar and baking soda. So, I applied some baking soda to a wet spot in the battery compartment, and observed no reaction. Hmmm. Maybe not an acid . . . wait! Of course, this is an “Alkaline” battery, just the opposite of an “Acid” battery. It should react with an acid, such as vinegar. Then I remembered that I had some pH paper. I applied the end of a pH strip to the liquid and the paper changed to a deep brown color. I compared it to the pH scale and matched it to a pH of 13 or 14, a very strong base. Yes, strong enough to warrant caution and apparently to burn through skin. I received the same readings from two more wet spots and tested the wet baking soda at a pH level of 8. So, the liquid in the battery compartment was a much stronger chemical than the baking soda.

I discovered that alkaline batteries contain potassium hydroxide, a chemical also known as lye or caustic potash. It is used to make paint remover and is the primary active ingredient in liquid drain cleaner. I’m sure you’ve read the warnings before using drain cleaners. They unclog drains by dissolving the gunk, including human skin cells, stuck in the pipes. The potassium hydroxide concentration for liquid drain cleaner is 25-30% and from 5-9% in Rayovac alkaline batteries. Since many things can cause battery leakage, we will now have to continually check these flashlights and this brand for wetness or corrosion.
I’ve felt the shock of 9 volt batteries and the heat generated from 4th graders making short circuits with D batteries, but this is the first suspected burn I have received in decades of working with batteries.

Our children enjoy working with batteries and lightbulbs, so we will need to keep a careful eye on things. Right now, the suspicious batteries are stored in a glass jar, and I will have another science teacher test them with a different batch of pH paper to compare results. I do not know the likelihood of this happening again. Maybe this was a random combination of manufacturer, user and tester error. So, in the meantime, my children will not be breaking open batteries like I did when I was a child!

If you have any similar experiences with burns from household batteries, specific problems with Rayovac or Sharper Image products, please let me know.
Signed M