"How Can Two PhDs Be So Stupid?"(followup)

Several days ago, I posted a confession about having set off a noxious spray inside the house. I recently received the following anonymous e-mail message. The content leads me to believe the person knows what s/he is talking about:

I believe that you are correct and that it was animal repellent, also known as pepper (capsaicin) spray [see attached document]. The product may have lost some of it's potency over the years, but it has a good shelf-life and is very effective when it comes in contact with mucous membranes like the eyes or nasal passages.

I have seen [official police] videos of it sprayed into police cadet eyes, and while it is possible for animals (like my brother who is [in law enforcement], protestors, etc.) to fight through the effects, most sane animals would retreat.

I have experienced the much diluted effects first hand. One day a disgruntled patient returned to a hospital where I was working and started spraying the stuff at staff. I was on the fourth floor of the hospital and my eyes were irritated, nurses were complaining of respiratory difficulties, all the doors to patients rooms had to be closed right up to the eighth floor of the hospital, etc. The effect lasted quite a long time (a hour or so).

As an aside, capsaicin (Zostrix) is actually used topically in medicine to treat nerve pain (it depletes the nerve of substance P [a neurotransmitter involved in pain transmition]). It initially causes burning, but as the substance P is depleted over time with regular use, it blocks pain transmission. As you might guess, many patients can't tolerate the initially burning phase.

The above is my best educated guess but thanks for the warning. Pharmacists put stickers on things all the time to remind people not to take their narcotics with alcohol and then operate heavy machinery, so don't feel bad.

Attached to the message was this piece, describing the effects of the spray on free-range black bears.

In a comment to the original piece, Jabber mentioned a bunch of PhDs sitting around who let a deck catch fire from using a chiminea. Well, thanks to him, we just bought one, but had the good sense to buy some concrete patio slabs to set it on. I think that's called "learning from history" so you don't repeat other people's mistakes. Or maybe that's another way of saying "investing in human capital".