Once somebody first figured out how to make a practical self-defense weapon using the heat from chili peppers, the world of personal protection changed - permanently.
The heat comes from something found in the fruit (chili peppers) of plants in the Capsicum family. That active ingredient is derived by extracting it from the plant using an organic solvent. After the solvent is gone, usually by evaporation, what is left is a waxy substance called oleoresin capsicum (OC). Since it doesn't work to hold a lump of it in your hand and then blow, what has to happen for it to be useful as a weapon?
Start by grinding up the OC and putting it in an emulsifier, like propylene glycol.
Definition time: an emulsifier is a mixture of two liquids which are not mixable, like oil and water (example: that vinaigrette dressing which you have to shake up every time you want to use it). An emulsifier keeps the two parts mixed together even if you don't shake the container. However, if you read the directions on aerosol cans, many of them say to shake before using. That's to get the unbendable parts mixed together again, just like with the salad dressing.
The next step is to suspend the OC in water, using an emulsifier.
Finally, put all that into a pressurized canister, and there you have it.
Pepper spray is effective because it is a lachrymatory agent.
Definition time: that means it is a chemical compound that is highly irritating to the eyes. Technically, tear ducts are called nasolacrimal ducts. They literally carry excess tears from the eye area into the nasal cavity (that's your nose). That the two parts are connected is part of why the nose often runs when a person is crying. It's a function of excess tears looking for an escape route.
When the eyes are irritated by a lachrymatory agent, like pepper spray or tear gas, the person will become intensely uncomfortable. The eyes usually slam shut and they produce lots of tears in an effort to wash out the offending substance. Many people even experience temporary blindness.
The product is available in a range of strengths, including those suitable for stopping dogs and bears, as well as human beings. And, since the canisters are available in a range of sizes, all you need to do is pick one that fits your hand or bag or pocket.
The good news is that the canisters are equipped with safety latches to prevent accidental discharge and the products provide low-cost, effective protection.
