Since there were a number of comments about the effectiveness being a 'myth', I looked for the ingredients in a common 'wasp spray' and I think that the main self defense component is in the 'other ingredients'.
Wasp Spray (Raid) –
99.60% Other Ingredients
In a report by the New York
environmental Protection Bureau, dated May 2000 (?) ordered by Elliot Spitzer, New York’s then Attorney General, it was determined “Pesticide products contain a variety of ingredients that either are known to be toxic or have not been adequately tested for toxicity and the public is denied of their presence.”
These inert products can include:
Chlorethane - It is a colorless, flammable gas. Ethyl chloride is supplied as a liquid in a spray bottle propelled by its own vapor pressure. Like other chlorinated hydrocarbons, it is a central nervous system depressant
, albeit a less potent one than many similar compounds. People breathing its vapors at less than 1% concentration in air usually experience no symptoms. At higher concentrations, victims usually exhibit symptoms similar to those of alcohol intoxication
. Breathing its vapors at 15% or higher is often fatal. [This likely is the propellant]
Cresoils - It consists of a solution of mineral oil
, preferably of an asphaltic base, and cresoil, or cresylic acid. For general use the solution should be in the proportion of 95% of mineral oil
. [Not sure but perhaps some of the pesticide dissolves in the mineral oil and this then provides a kind of persistent effect]
Dibutylphthalate - The National Fire Protection Association has assigned a flammability rating of 1 (slight fire hazard) to dibutyl phthalate. Flash point: 157 degrees C (315 degrees F) (closed cup). Contact of the surface of the eye with DBP causes pain and tearing, but no permanent eye damage. The acute toxicity of dibutyl phthalate is low. A worker who reportedly swallowed 10 grams of DBP became nauseated, dizzy, and developed photophobia, tearing, conjunctivitis, keratitis with loss of corneal epithelium. He recovered promptly and completely.
Dimethylphthalate - The National Fire Protection Association has assigned a flammability rating of 1 (slight fire hazard) to dimethylphthalate. Flash point: 146 degrees C (295 degrees F). Has been used as an insect repellant since World War II; there are no reported cases of skin irritation or sensitization. If splashed into the eye, dimethylphthalate causes pain and may cause mild and transient damage. Ingestion causes irritation of the esophagus and stomach with hemorrhage, vomiting, diarrhea, possible central nervous system depression, coma, and hypotension. It is also reported to cause burning of the lips, tongue, and mouth. Inhalation produces coughing.
Epichlohydrin - (AKA Epichlorohydrin) Flammable - note wide explosion limits and low flash point. Flash point: 32 C (closed cup); Explosion limits: 3.8 - 21%. Poison. Harmful if inhaled - may cause delayed lung damage. May be fatal if swallowed. Causes burns. Contact with eyes may cause permanent damage.
Isophorone - is used mainly as a solvent and is also used in some herbicide and pesticide formulations. The only acute effects of isophorone reported in humans are irritation of the skin, eyes, nose, and throat, headache, and dizziness.
Napthalene - (AKA mothballs) Not soluble in water
so likely dissolved in a hydrocarbon liquid if present. Cataracts have also been reported in workers acutely exposed to naphthalene by inhalation and ingestion.
Phenol - The National Fire Protection Association has assigned a flammability rating of 2 (moderate fire hazard) to phenol. Flash point: 79 degrees C (175 degrees F) (closed cup).
Local effects include irritation of the eyes, skin and mucous membranes. Concentrated phenol solutions are severely irritating to the human eye and cause conjunctival swelling; the cornea becomes white and loses sensation.
Toulene - Flash Point: 4 deg C., Flammable liquid and vapor. Causes eye, skin, and respiratory tract irritation. Breathing vapors may cause drowsiness and dizziness. May be absorbed through intact skin. Aspiration hazard if swallowed. Can enter lungs and cause damage. Eye: Causes eye irritation. Vapors may cause eye irritation. Skin: Causes skin irritation. Ingestion: May cause effects similar to those for inhalation exposure. Inhalation: Causes respiratory tract irritation. Inhalation of high concentrations (>200 ppm) of toluene are clearly associated with lassitude (weakness, exhaustion), impaired coordination, and impaired reaction time.
Snopes had an entry on this issue and noted that an experienced self defense instructor recommended the use of this spray. They did NOT debunk it as not working or being ineffective.
My initial thought was that such a device is likely to be effective – not that the minor amount of active ingredients (0.4%) is likely to do any significant damage to a human, but that the hydrocarbon carrier was likely to be unpleasant when sprayed onto the face and upper torso of a miscreant. Judging by the effects that the various ingredients have on the eyes and respiratory tract, one could certainly expect a useful self defense reaction. I have also noted that should the chemical effects not be enough to discourage an attack, one could potentially use an incendiary source to set fire to the miscreant’s saturated clothing
which is likely to cause them some distraction and disrupt any continuing attack.