How do anticling sprays work?
First we need to quickly review static electricity.
Normally, the atoms that make up the objects around us have equal numbers of positively charged protons in their nuclei and negatively charged electrons in orbit for a total electric charge of zero. If you put two objects in contact - let's say a sweater and your hair, as you pull clothes on in the morning - the odds are that one of them will be a bit better at holding on to its electrons than the other.
So when you pull the sweater away from your hair, the one slower to give up its electrons will have a negative charge, while the other will be somewhat positive. The two things will then attract each other, and this is the electrical pull - or static electricity - that makes your hair want to cling to the sweater.
The fact that static electricity tends to be a problem on cold dry days holds the key to making anticling or antistatic spray. On warmer, damper days, the air has more water vapor in it, and pretty much all surfaces get covered with traces of water that serve as electrical conductors. That means that electrons can easily flow from whatever is negative to whatever is positive, causing none of the imbalance that results in static electricity.
Antistatic sprays are basically just things that either conduct electricity, or grab onto traces of water to help conduct electricity. In a pinch, you can use a fine spray of ordinary tap water to get rid of static electricity. (Note that if your hair is wet, there's no static problem.)
So are the commercial antistatic sprays as safe to inhale as water? The chemicals in the sprays are chosen because they are not very toxic, but I wouldn't go around spraying them into my mouth or nose.
Dr. Knowledge is written by physicists Stephen Reucroft and John Swain, both of Northeastern University. E-mail questions to drknowledge@globe.com or write Dr. Knowledge, c/o The Boston Globe, PO Box 55819, Boston, MA 02205-5819. 