Monday, January 9, 2012

Pepper Spray Testing Methodology

Ok, that title makes this sound far more sophisticated than it actually is. Basically, I don't want to have to deal with the 45 minutes of hell that a decent pepper spray will put you through if sprayed to the face, but I still want to be able to compare sprays. So, with each spray I will be doing the following:

1) Spray into an open, outdoor area to gauge its effective range, its spread, resistance to wind, etc.
2) Spray briefly (1/4-1/2 second) onto my forearm with the palm up, to estimate raw heat.
3) Take a deep breath near the spray site on my forearm to judge its effects on breathing.

Obviously no spray's effects will be as impressive on my forearm as on my face, but so long as I test each spray the same way, I should get accurate relative rankings of the sprays.

That's it! Nothing fancy there at all.

P.S. It's far above my pay grade, but there's a company called Pepperball Technologies that manufactures what amount to paintballs filled with a powder mixture that contains a synthetic version of capsaicin (It goes by PAVA, Capsaicin II, and some other names). The chemical is just as hot as capsaicin, and their most intense mixture is 5% PAVA. Considering the hottest CLAIM (not substantiated) for a regular spray is 3.0% CRC, and probably only half of those, if that, are the hottest capsaicinoids, that powder mixture is over 2 times more powerful than the world's hottest pepper spray. Scary! And I want some :)

Pepper Spray Basics

Despite how confusing the marketing for pepper sprays can make it seem, the basic workings of pepper spray is fairly simple. Pepper spray contains some of a family of chemicals called capsaicinoids, and those chemicals are responsible for the burning, coughing, sneezing, etc. At the end of the day, it is the percentage of the spray that is each of the capsaicinoids that determines the heat of the spray itself.

Why do I say each of the capsaicinoids? It is because there are five primary capsaicinoids, and they fall into two basic levels of heat. Two of them, capsaicin and dihydrocapsaicin, are basically the same strength, and are roughly 1.7-2.0 times as strong as the other three. So, if every spray told us what percentage of the spray's contents were each capsaicinoid, we'd have a perspicuous representation of the raw heat of the spray.

As life would have it, of course, no company indicates their spray's heat in this way. Instead, there are two primary ways companies indicate the strength of their product. The first, and far most common among self defense sprays, is to indicate the spray's OC% and the SHU, or Scoville Heat Units, of the OC. OC is short for oleoresin capsicum, and is the part of the spray that is actually derived from peppers; in other words, the OC is where the active ingredients are. The OC%, naturally, is the percentage of the spray that is OC. Scoville Heat Units are a subjective measure of spiciness attributed to, you guessed it, a chemist whose last name was Scoville. Basically, the SHU rating of an OC, or of a pepper, of a salsa is the degree to which it must be diluted before the spice can barely be tasted. Now, when pepper spray manufacturers refer to the SHU of their spray, they are actually referring to the SHU of the OC (unless otherwise indicated; some brands, like Heatwave, only test the heat after it has left the can).

Having said that, since OC% is the percentage of the spray that is OC, and since the reported SHU of a spray is the SHU of the OC, we can get a rough estimate of the raw heat of the spray by multiplying the OC% by the reported SHU of the OC. So, a 10% OC spray listed as 2,000,000 SHU can be (again, roughly) thought of as outputting a spray that is 200,000 SHU. This is important because some manufacturers emphasize the SHU of their spray, but don't point out that the OC comprises a tiny percentage of the spray, or do the opposite and point out that the spray has a large amount of OC in it, but ignore that the OC is quite weak.

As I have emphasized, though, this is only a rough estimate of raw heat. It is definitely not the alpha and omega of pepper spray effectiveness. For one thing, since pepper spray manufacturering is not regulated, there's no guarantee that the company's claims are even true. A company that claims a 10% OC, 2,000,000 SHU spray might actually turn out a product that is 7% OC, with an OC that is only 1,500,000 SHU. The difference in raw heat would be noticeable! (200,000 SHU spray out the nozzle in the first case versus 105,000 for the second). Second, pepper spray effectiveness is affected by other factors, like delivery method, a topic we will address soon.

I mentioned above that there are two main ways of marketing the strength of pepper sprays. The first, which we just examined, is most common for self-defense sprays. This second one is more common for bear sprays (pepper sprays designed to deter bears, reasonably enough). This second method is to list the percentage of the spray that is capsaicin and related capsaicinoids, or CRC%. For example, the EPA, which regulates bear sprays, requires that bear sprays have at least 1.0% CRC and no more than 2.0% CRC.

There is a problem with this, however. Remember what I said earlier about there being 5 capsaicinoids, with 2 of them being clustered near the theoretical maximum? Capsaicin is 16,000,000 SHU, and dihydrocapsaicin is usually put around 15,000,00; remember, those figures are subjective and not etched in stone. The other three, though, range from 8,000,000 to 9,000,000 SHU. So, a spray containing only 2.0% CRC, but with all of it coming from capsaicin, would be expected to have roughly 320,000 SHU coming out of the nozzle, while another with 3.0% CRC, but with all of it coming from the weakest capsaicinoid, would be expected to have roughly 240,000 SHU coming out of the nozzle.

The result of all this is that since none of the pepper spray manufacturers are required to indicate the strength of their sprays by listing the percentage of the spray that is each of the capsaicinoids, and are not regulated, the manufacturer's claims can only be taken to be a (very) rough indicator of the spray's hotness. This is what necessitates subjective testing of the spray's effects. Objective testing of the spray's contents would be very nice, but I haven't the money or equipment to engage in testing that extensive.

The final piece of this puzzle is the delivery system. OC is almost always used in a spray, and then there are three basic spray patterns used. The first is a narrow stream, which is easier to use when there's a stiff breeze blowing about, but requires more precision in aiming. The second is a fog pattern, which generally has a shorter range, is more affected by wind, but requires less aiming. It also affects the respiratory system more easily, since it can be breathed in more readily. That last factor is the reason I tend to prefer fogs or cones (cones are basically a more narrow fog, so you get the best of the stream and fog worlds). The final distinct patter is foam/gel. These are also easier to use in wind, but they are also easier to clean off, which is excellent for a controlled situation like a prison (where they are most common), but not so great in a self defense situation. As a side note, one of the reasons the OC% * SHU formula can't be the final word on pepper spray effectiveness relies on the behavior of the fog patterns. For a fog to work well, it has to be turned into very fine particles; however, OC is an oil, and oils don't very much like to be turned into fine particles. So, even though a 2% OC at 5,000,000 SHU would be expected to output 100,000 SHU, and 20% OC at 500,000 SHU would be expected to do the same, the former would likely be more effective as a fog, since the latter would be quite oily.

Well, that rounds up the pepper spray basics. In the next post I'll briefly outline the methodology of the tests I will be doing with pepper sprays, and then it'll be off to the races with testing!

Introduction to Pepper Spray Reviews

Pepper spray is a very popular tool for self defense, riot control, and other situations in which effective non-lethal deterrents are needed. However, this popularity has not been accompanied by an increase in accurate common knowledge about how to choose among the numerous alternatives.

You see, I became interested in carrying some sort of self defense weapon just in case good sense wasn't enough to steer clear of trouble. The obvious choice (for many people, at least) is to carry some sort of handgun. The trick with handguns, though, is that quality guns are expensive,  require quite a bit of practice to reach a skill level useful in an adrenaline-filled real life crisis, are illegal to concealed carry without a license (in some states/districts it is illegal, period), and are highly subject to legal repercussions even if used properly (that is, are you sure that guy with the knife was trying to kill you? If a jury can be convinced shooting him was excessive, you and the bad guy both go down).

Knives, batons, and stun guns all suffered from a similar flaw I really didn't like: you have to be quite close to your assailant to use them. I would like to have the ability to hit from a bit of a distance; it's just safer that way.

So, I decided that I would just get the best pepper spray product I could justify purchasing, and voila!, my problems would be solved. Right? Well, as it turned out, not so much. Pepper sprays are marketed in all sorts of bizarre ways, and many of the objective features pointed to by the marketing are only one piece of the pepper spray effectiveness puzzle.

What makes the situation worse is that when it comes to subjective reviews of pepper spray effectiveness, it is difficult (as near as I can tell it is impossible) to find a site where many different sprays have been tested by the same person. There are plenty of subjective reviews, of course, but to compare apples to apples we need a wide variety of sprays tested by the same people.

This blog is my humble attempt to clear some of the confusion about the basic workings of pepper spray, and to review several of the popular varieties by testing them on yours truly. I hope this helps some of you out there who are just confused about all of this as I was!