Jim,
As I recall the SMC post was a guy in California who had an Oneida Dust Gorilla and the fire inspector was giving him grief by requesting that he provide UL certification. Having spent 5 years as an inspector in Houston and another 10 years supervising inspectors I can see both sides of the problem.
UL is not a consumer watch group. Underwriters Laboratories was set up as a private entity by insurance underwriters in order to save the insurance industry $$. The standards they test to are written by outfits like National Fire Protection Association (NFPA) Compressed Gas Association (CGA) and an alphabet of others--ASTM, ASME, etc. As Frank said, the committees that write the standards are boring, but everyone on the committee is there to avoid goring their own ox. It is a constant fight, with trade offs, to save the company money and avoid regulation as much as possible.
Then, many inspectors are not adequately trained beyond basic inspections based on one of the standard companion (to the building code) fire codes. In smaller towns (and some big ones) they have the attitude that if the fire marshall likes it it's okay and if he doesn't it's against the law. Very often they will attempt to apply a code section inappropriately such as requiring flammable warehouse requirements in a hardware store. In the case of the Dust Gorilla, what the inspector was looking for was a requirement that started out dealing with grain elevators, which have a tendency to blow up due to fine dust. I suspect (haven't read the requirement lately) that the standard was prepared for industrial installations (read grain elevator) where you would have 15 hp and up cyclones and would require bonding of everything metallic in the structure. Somehow this standard right or wrong was being applied to a small carpenter/artist shop. The problem here is that Oneida or anyone else selling a major industrial rig would pay for testing on a big $$ project, they won't pay to test a collector that cost less than $1000.
Most inspectors, after a few years, develop what I call "walking around sense," and will exercise some discretion. In the case of the Oneida, they might require bonding, and would demand good housekeeping and other dust control, then sign the guy off. The problem with that is if they overlook something and have a loss of life situation, then someone will find a lawyer and sue.
Happily, in Texas and a number of other states, we can do pretty much as we please in our garage shops and anywhere outside the city. Most of the equipment we use may have a UL listed motor, but that is the extent of their listing, and the motors are listed for "normal" operation (not explosive atmosphere).
Since I was an honest inspector, I used to openly joke about having to economize, since "graft is down by 20% this month." Since Fire Departments are paternalistic organizations, the one inspector I suspected of taking $$ decided to retire before I had to take action.
Suffice it to say there were offers.