Banning Dihydrogen Monoxide: Examining the Analytical Process

05 Apr

So, I’ve pulled the dihydrogen monoxide gag on you, and unless you’re one of only two students out of all those who attended that presentation, you signed the petition to ban it.


The point of that rather detailed piece of deception wasn’t to pull a fast one over you, but to stress that when you sign your name to a “call to action” (that is, something that calls for people to do something), you are essentially claiming the authority for yourself to do so. You are saying, “I have enough authoritative knowledge of the subject that my recommendations should carry weight.”

That most people who do sign such documents have no such authoritative knowledge, and that they nevertheless still expect their recommendations should be approved, is sad, disheartening, and quite frightening.

I would prefer that students from my class are not among them.

I would prefer that students from my class do all they can to actually gain authoritative knowledge of a subject before committing themselves to a call for action.

So let me be clear about the purpose of the Dihydrogen Monoxide gag.

It wasn’t about knowing that DHMO is actually water.

We wouldn’t recognise most of the common substances we use daily if they’re referred to by their chemical name. There’s no reason why we should. The fact that you might not know that sodium chloride is regular table salt, or that sodium hydrogen carbonate is simply baking soda, does not indicate that you, or anyone else, is particularly ignorant. It just means that you don’t happen to know the chemical names for things.

It was about taking authority.

First, that when you start telling other people what they should and shouldn’t do, you had better be deserving of the authority you are assuming for yourself.

Second, that information from a single sponsor (in this case the frictional Toronto Citizens for a Safe Environment) is never sufficient for this authority. Many celebrities become “authorities” on various issues after having heard information from only one sponsor.

For example, Pamela Anderson spent many years protesting against the inhumane treatment of chickens on Kentucky Fried Chicken farms. Having received all her information from PETA, poor Pamela (and the rest of the dupes) remained completely unaware that Kentucky Fried Chicken doesn’t have chicken farms, and never has! They buy their chicken from the same producers who supply your local supermarket.


Third, that no matter how convincing the information on a particular subject may be, you do not attempt to claim any authority on it until you have spent a significant amount of time doing your own research.

Research involves asking questions

Research without direction is pointless. It’s nothing more than a handful of facts thrown onto the paper. All research needs some kind of direction.

This direction is provided by your questions.

For instance. On several occasions I’ve mentioned that I don’t like hot-air hand driers in public washrooms. So why don’t I like them?

  1. They take longer, and since only one person at a time can use them, they hold everyone up.
  2. They do not save trees, since paper companies are our best forestry guardians. It’s their business to keep forests healthy.
  3. The warm, damp interior of the machines provide a breeding ground for bacteria, which are then spread throughout the room by means of the blowing air.

So what do I need for research?

Is it true that they take longer?

I do a Google search on: hot air driers public washroom slower

I don’t use quotation marks. I’m not looking for a site that has the phrase “hot air driers public washroom slower.” I’m looking for a site that has these words in it.

Here are my results.

Pretty lucky.

The first thing I check out is the comparative study of various hand drying techniques done by the University of Westminster. While a university study may be of little value in a far-ranging subject such as climate change or the effectiveness of vaccines, there’s a good chance it can provide some kind of decent data for a subject like hot air hand driers.

As it turns out. I hit pay dirt.

First of all, the study investigates “3 different handdrying methods.” Each drying method is rated in four ways:
  • “Drying efficiency”
  • “Changes in the numbers of bacteria on the hands after drying”
  • “Potential contamination of other users”
  • “Fhe washroom environment.”

One of the ways they measured “drying efficiency” was through speed of drying.

They tested five different types of papter towels, “PT1,” “PT2,” “PT3,” “PT4” and “PT5” against two types of blow-drying: the regular warm air drier, or “WAD” (seriously?), and the “Dyson Air Blade,” or “DAB”.

Their drying efficiency was rated by measuring the amount of time it took for the hands to achieve a dryness rate of 90%. The shorter the time, the more efficient the method.

Here is a chart of their results.

As you can see, all five types of paper towels, PT1 – PT5, succeeded in drying hands in a quarter of the time it took the warm air dryer, WAD (and couldn’t they have called it a warm air blower, or WAB?)

The Dyson, on the other hand, matched the paper towels in drying efficiency.

Huh. Didn’t expect that.

Skimming through the material, I see that another test measured the amount of bacteria on the hands before and after each type of hand drying. So which method left behind fewer bacteria?

Well, here’s their chart.

Note carefully what each thing means.

The letters along the left side (NA, CLED, MSA) are different growth agents. In order to measure bacteria, growth cultures are used, but each has somewhat different characteristics, and so some are better for certain bacteria, while others are better for another kind of bacteria. By combining several different growth cultures, it lessons the chance of missing some types of bacteria.

And as an aside, I think quite highly of these researchers and the way they work.

Now the numbers are colour coded, as well as having minus or positive signs beside them. These numbers illustrate whether there was more or less bacteria left on the hands after using each drying technique. Numbers in green mean that there were fewer, while numbers in red indicate that there were actually more bacteria on the hands after drying them.

If you look at the chart, you will see that they only tested two of the paper towels. The reason for this would likely be a matter of time and resources. The paper towels seemed to be working roughly the same, so why not save time and just use a couple?

Now the chart clearly shows that the paper towels were very effective in reducing the number of bacteria left on the hands. Both the warm air drier and the Dyson Blade ended up actually adding bacteria — and in significant numbers.


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