Thursday, July 5, 2012

8 July 2011 – Mmmm, incapacitating!


Bit of a shocker this week as a police officer who intervened in what seemed to be a domestic dispute ended up with a face-full of bear spray.  It seems that the perpetrator had flagged the officer down whilst chasing another man down a street in Barrie shortly before midnight Wednesday.  When the two caught the fleeing man, the first man cut loose with the chemicals.  Unfortunately for him, he hit the police officer with it.

Unfortunately for the officer, too. Bear spray is pepper spray, more or less - it just tends to come in concentrations, quantities and delivery systems less appropriate to subduing greasy hippies screaming anarchist slogans and more suited to discouraging a 500-pound ursine predator from killing and eating you. Some of the more popular commercial formulations contain relatively high percentages of the active ingredient, oleoresin capsaicin (OC to chemical weapons aficionados), and come in pressurized delivery canisters containing hundreds of grams of the concentrated pepper extract dissolved in alcohol or some other organic solvent. Instead of having dispersal mechanisms designed to dispense a fine mist of agent, bear sprays tend to have nozzles designed to hit a relatively small target up to thirty feet away. This is necessary because aggressive or hungry bears often need a lot of persuading, and unless you hit them in the eyes, nose and mouth, they probably won’t even notice the stuff until it’s too late. For you, that is.
Figure 1 - Bear Sprays and how they work

Figure 2 - Oleoresin Capsaicin: structural formula

OC, incidentally, is a magnificent empirical proof of evolutionary adaptation.  Birds do not have the molecular receptors for capsaicinoids, and thus feel no burning sensation when they ingest the peppers.  Birds also don’t have molars.  Bird feces are the primary means of spreading chilli seeds.  Mammals, by contrast, have molars, which destroy the seeds by grinding - and mammals also have capsaicinoid receptors, meaning that they feel pain from ingesting OC.  Production of OC is a defensive mechanism that evolved to deter only creatures that ingest and destroy chilli seeds, not creatures that ingest and then spread them.  It’s fascinating to note that tarantula venom also activates precisely the same pain pathways - an example (one of the only ones known) of a plant and an animal evolving separate chemical mechanisms for targeting the same mammalian vulnerability.

How hot is OC, anyway?  Well, that’s a good question.  Pain measurement is a science still in its infancy, and unlike other systems of measurement, there is no precise objective scale; pain, in other words, is a subjective experience, and is different for everyone.  The piquance of chili peppers is measured on the Scoville Scale, using Scoville units (SHU).  The scale is 99 years old this year, having been invented by Wilbur Scoville in 1912, although modern measurements, using concentrated pepper extract dissolved in organic solvents in liquid chromatography, have come a long way since the days of laudanum and radium pills.  Scoville’s original method was entirely subjective; capsaicin oil from various different peppers was dissolved in alcohol and the strength of solution gradually increased until heat was detectable orally by a panel of five tasters.  The dilution ratio at which heat is first detected is the Scoville rating.  Using this system, sweet or Bell Peppers have no measurable piquancy at all (and thus a Scoville rating of zero), while the hottest of commercially cultivated peppers, like Habaneros or Scotch Bonnets, have a rating of around 200,000.  In other words, the capsaicin oil that these peppers produce must be diluted by a factor of 200,000 before their heat becomes undetectable by humans.

Figure 3 - Red Savina Habanero pepper (ripe)
The hottest naturally occurring capsaicin oils are produced by the Red Savina Habanero pepper, which has a Scoville rating of about 580,000.  Pepper spray, however, uses either concentrated extracted capsaicins from the hottest peppers available, or synthetically-produced capsaicinoids.  Here’s a comparison.

·         Banana peppers: 100-500 SHU

·         Jalapeno peppers: 3,000 - 6,000 SHU

·         Habanero peppers: 100,000 - 350,000 SHU

·         Red Savina habanero peppers: 350,000 - 580,000 SHU

For those who want to kick it up a notch and meet the Space Coyote, there’s the Naga Viper, the Naga Jolokia or Ghost Chili, the Trinidad Scorpion Butch T, and the appropriately named Infinity Pepper, all of which clock in at 855,000 to 1,463,700 SHU.  Chilly Chillies, a specialty hot stuff company which used to have a shop on Sussex Street in Ottawa in front of the US Embassy, used to sell concentrated Infinity Pepper oil in a small glass phial with a wax-sealed stopper shaped like a skull.  You had to sign a waiver to buy it.  My eyes started watering every time I went in there.

Beyond this point we cross into the realm of law enforcement-grade pepper spray - pure, concentrated capsaicin oil either extracted from the hottest natural chillies, or produced in laboratories by organic synthesis.  Pure OC comes in at around 5,000,000 on the Scoville scale.  One cup of this stuff dissolved in an Olympic-sized swimming pool of alcohol would still be detectable.  From the point of view of getting a face-full of highly concentrated OC, the difference between natural Habaneros and cop-quality Pepper Spray is like the difference between a 5 kt or 5 Mt explosion - it doesn’t really matter how big the bomb is if you’re at ground zero.  Where it does matter is when you’re hosing down a crowd, because even the slightest hint of mist from a dispenser putting out 5,000,000 SHU spray will be enough to temporarily incapacitate whoever’s on the receiving end, whether it’s some angsty teenage anarchist with an iPhone, an iPod, an iPad, an autographed copy of Naomi Klein’s NoLogo in his designer backpack, Nikes on his feet, and a "Down With Capitalism" sign scrawled in orange Highlighter on a Wal-Mart box...or an angry bear looking to score lunch.

Speaking of the NoLogo crowd, if you’re planning on crashing the next G8 summit, you should know that, like CS, OC isn’t soluble in water and can’t be washed off no matter how hard you try.  Rubbing affected areas merely pushes the oil into the skin, prolonging the discomfort.  Anarchist groups have circulated recipes for home-made “pepper spray decontaminant” (including ingredients like Maalox, lidocaine gel and milk) but none of these really work.  Ambulance attendants report that washing affected individuals with baby shampoo seems to work well - but in fact any soap would work against the oil, and baby shampoo simply has the virtue of being low-irritant on areas most likely affected by OC, like the eyes and other mucous membranes (Johnson and Johnson’s “No More Tears” might be a good bet).  Unlike CS, OC isn’t deactivated by sodium metabisulfite - but unless you’re a passionate home wine-maker, you probably don’t have any of that around the house anyway.

Putting on my CWC-bore hat for a minute, it’s worth noting that OC, like CS (“tear gas”) isn’t on the Schedules of Chemicals and thus isn’t “controlled” per se by the Chemical Weapons Convention.  However, like CS, it does meet the definition of a “riot control agent” (RCA) under paragraph 7 of Article II (“Any chemical not listed in a Schedule, which can produce rapidly in humans sensory irritation or disabling physical effects which disappear within a short time following termination of exposure”), and thus is subject to declaration requirements under Article III, paragraph 1(e) of which requires each State Party, “with respect to Riot Control Agents”, to “specify the chemical name, structural formula and Chemical Abstracts Service (CAS) registry number, if assigned, of each chemical it holds for riot control purposes.”

Which introduces something of a conundrum.  You see, this declaration requirement does not include RCA held for “law enforcement purposes”, and the language in the “purposes not prohibited” definition (paragraph 9 of Article II) refers to “law enforcement, including domestic riot control purposes” as a “purpose not prohibited”.  In other words, the Convention text specifically contemplates “domestic riot control” as a subset rather than the totality of “law enforcement” (this was done to allow member states to continue to use chemicals for judicial execution), which means that there is the acknowledged possibility that States Parties may use OC, CS and other RCA for “law enforcement” purposes other than “domestic riot control”.  One example would be, subduing unruly arrestees.  The declaration requirement also does not include “military training purposes”; and since the Canadian Forces (to take one example) do not have “riot control” as a specific defence task, technically speaking we do not have to declare any of the tear gas or other RCA we hold (e.g., OC held by the MPs, or bear spray held by range control authorities at rural military bases), so long as we don’t use it, or intend to use it, as a “method of warfare”, which is prohibited under paragraph 5 of Article 1.

Of course, none of this means you can blast a cop in the face with bear spray and just walk away.  The fellow in the story cited above has been charged with possession of a dangerous weapon and (surprise, surprise!) breach of probation.  All of which, to paraphrase a former giant of Canadian politics, means that the best place for pepper is probably on your plate.

Piquantly yours,