Pepperspray is widely considered to be one of the best self-defense weapons available. A pepperspray canister is easily concealed upon one’s person, will allow one to engage targets outside of grappling range, has minimal risk of inflicting serious injury upon others, and (when used properly) will usually repel (if not incapacitate) most attackers. Due to these factors, pepperspray (particularly Mace Pepperfoam) is highly recommended for defensive purposes.

Because it is non-lethal, easily discharged, and has only temporary effects, most law-abiding citizens would have no reservations about firing it directly into the face of a threatening miscreant with only minimal provocation (in effect, a "preemptive strike"). Preemptive strikes are an important option when dealing with street predators, due to the fact that they will often use guile to appear non-threatening as they carefully move into range for a surprise attack. If you feel menaced by a stranger who is moving into your personal space and acting like he wants to place his hands on you (even if no overt threat has been made), and he will not be dissuaded by stepping back or telling him to leave you alone (especially if you happen to be in a relatively secluded area, away from witnesses who could potentially help you), you should pull your pepperspray out of your pocket (your hand should’ve already been on it) and fire a long burst straight up his nostrils. This should be done in a single movement without any hesitation whatsoever — never attempt to "threaten" someone by displaying the cannister. Not only will it make a poor threat, but if the miscreant sees it, he will either try to jump you in hopes of wresting it away, or take precautions (such as covering or averting his face) prior to continuing with his attack. Taking him by surprise will eliminate these options, and ensure greater accuracy.

Pepperspray is available in several concentrations and can be fired from a wide variety of aerosol canisters. These vary greatly in quality and reliability, and care must be taken in selecting one that will work when needed with a minimum of fumbling. Poorly designed canisters have buttons that jam (or safeties which fail to disengage). Typically, the higher the concentration the more effective the agent, but I have heard arguments disputing this. Most sprays are 10% oleoresin capsicum (cayenne pepper). Formulas containing CN or CS "tear gas" are seldom seen outside of the military, as they are widely being considered obsolete and inappropriate for either police or civilian use. In the rare instances that CN is encountered, it is usually encapsulated within a bursting projectile, such as 40 mm grenade launcher rounds (which can generate enough heat to inadvertently start a fire). Most experts feel OC pepperspray is far more effective than either CN or CS.

Spray canisters usually fire either a thin stream of liquid (sometimes called a "shotgun stream") or a fine misting, at a variety of ranges. The average range is about 7 feet. "Foggers" fire a thick cloud over 15 feet away, and often appear like miniature fire extinguishers. Spray canisters can be fired in a series of short (or long) bursts, or can be emptied by keeping the activator button depressed (probably not a good idea). After several bursts, both volume and pressure will be significantly reduced, and you are strongly urged to replace the unit at your earliest convenience rather than continue to rely upon it. Units should also be replaced after their stamped expiration date.

Pepperspray can be squirted out of pens, flashlights, and wrist mounted devices, as well as fired from starter pistols or derringer-like flare projectors. I have seen one device which resembled a large plastic pistol with a wide cylindrical body, which was capable of firing a high-pressure stream at extended ranges (although, due to its considerable profile, it would be difficult to conceal under one’s jacket). Pepperspray can also be fired from concealed vehicle-mounted nozzles (usually mounted above the driver’s side window). ASP makes a yawara-style keyring which fires a high-pressure, cone-shaped blast from the base. The ASP "key defender" comes with one HEAT cartridge and one inert TEST cartridge for training, and extra dual cartridge packs are available. As the entire cannister is emptied at once, no second shot is available. A wide variety of hidden spray projectors exist, as well as grenades, boobytraps, and generators (large devices which produce massive volumes for crowd control) — but these are not widely available.

Better, in many ways, than pepperspray is Mace Pepperfoam, which squirts out in a thick stream, sticks to its objective, and will not produce residual misting. The foam resembles shaving cream, is easily aimed, and you will actually see the agent contacting your target. Not only does the OC impregnated foam obscure vision, but it affects only the target, preventing the room from becoming temporarily uninhabitable. Pepperfoam can actually be sprayed into the backseat of an automobile by the driver without affecting any of the other passengers! Furthermore, this product utilizes a top quality cannister which features a "flip-top" safety cap and thumb actuator button. Mace Pepperfoam should definitely be your spray weapon of choice (unless your needs include filling a corridor with gas, or dispersing large groups, in which case a fogger should be utilized).

Pepperspray is fired into the attacker’s face, aiming for the mouth, nose, and eyes. If you extend your arm, the cannister can be grabbed or knocked aside, so be sure to keep it close to your body. Keep the stream firing steadily into the attacker’s face (unless there are multiple attackers, in which case you’d attempt to hose them all down before fleeing), following him around as he turns his head. An inaccurate or partial application will not be as effective. Residual misting will effect an entire room for an extended period of time, depending on quality of ventilation (if you need to cross a contaminated area, keep one eye shut and do not breathe). It should not be sprayed into the wind (duh). Effects of pepperspray include: impaired vision, choking, nausea, and general incapacitation.

It is a safe and effective non-lethal weapon, provided one has practiced enough to gain familiarity with it. Be warned that while OC pepperspray has the power to incapacitate most assailants if used correctly, it is not guaranteed to stop them. A determined assailant, or one under the influence of drugs, may continue to attack even after being sprayed in the face repeatedly. It works best against vicious dogs (who have a plethora of nerve endings on the mucous membranes of their wet noses) and cowardly punks.