I’m perpetually irritated by the tendency of self-important authority figures to hand out their decrees without any justification whatsoever. Governments are particularly bad for this, but so are the little tin-pot dictators that infest corporate legal and safety departments.

Do not mix with other cleaning products. Do not make statements concerning bombs. Do not sit on the flower planter. Do not taunt Happy Fun Ball. Do not tamper with the ground pin. Do not use to clean inside your ear. Do not use this product for the purpose for which it is very obviously intended.

Some of these decrees are just power trips. Some are shameless ass-covering manoevers. Some are just silly. And some are very good advice. But it can be hard to tell which are which sometimes. For the ones that are legitimately good advice, a little bit of justification can go a long way to encouraging compliance. If mothers are made to understand why it is better that they put on their own oxygen mask before they help their child, they are much more likely to actually follow the instruction. (The reason:if your child passes out from lack of oxygen, you can still help your child, no harm done. But if you pass out from lack of oxygen, your child probably can’t help you, and you’ll die.)

At the business park where I work, our main ring road that joins the buildings has a posted 10km/h speed limit. Have you ever actually tried to drive 10km/h? It’s really hard. Some people walk faster than that. An automatic will idle faster than that, you have to ride the brake carefully to keep your speed down. A car with a manual transmission will stall, unless you delicately ride the clutch.

If the intent was simply to get people to slow down, it doesn’t work. Such a low speed limit is just a bad joke, worthy only of being mocked, or at best ignored. Had they set the limit at a more reasonable 30 or 40km/h, it might have a chance of being somewhat effective.

Just once, I’d like to have the person who decided on that speed limit behind me on that road. I’ll drive 10km/h. I bet that would really piss them off.

Anyway, what triggered today’s rant was the label on a bottle of brush-on wood preservative I bought. I’ve been rebuilding the shower in my master bath. Home Depot advises the use of pressure-treated wood to build the framing of the curb and around the shower pan. This is, presumably, to minimize damage should the shower pan leak.

It is often a good idea to use some brush-on end-cut treatment when you cut pressure-treated wood, to protect the core of the wood that was not reached by the pressure treatment. I thought it would be a good idea also to brush some onto the other existing untreated wood framing.

But the label on the bottle says “Not for interior use.”

No justification is given. No warnings about what terrible things will happen if I do, what the risks are. Just a decree handed down from on high. I know somebody in government or that company has done a risk assessment, and concluded that interior use is risky in some way. But there are a great many different uses that could be called “interior use”, surely they are not all equally risky. And there are many kinds of risks, and they may not all be applicable to me. They will be including their own legal risk in their analysis. Perhaps some bozo somewhere will use it to treat his baby’s crib, or make a kitchen counter with it, and end up suing the manufacturer for his own stupidity. Better, they think, to just blanket-forbid all interior uses.

I was able to find this directive from the Canadian government ordering manufacturers to include the phrase “Not for interior use” on their labels for copper napthenate and similar brush-on preservatives. The only reason given in the directive was that “label use patterns involving interior use are no longer considered appropriate.”

So, what is the danger of interior use, exactly? Is it that it will leach out of treated surfaces onto your hands and slowly poison you? Not buried under layers of mortar, shower membrane, more mortar, and ceramic tile, it won’t. Is it that it could leach down the shower drain? Only if the shower pan is leaky, which it will not be. Is it that the solvent fumes will poison me in the enclosed space? I’ll open a bloody window. Is it that it will release toxic gases if it gets burned in a fire?

What is it? C’mon, just tell me, so I can intelligently assess the risk for myself. Don’t just hand down the prohibition, and expect mindless obedience. Homey don’t play that.