Yesterday, we had the extended family over for Thanksgiving. The family tradition is that everyone comes to my house and I make a turkey in my turkey fryer and the ladies make all kinds of side dishes in the house.

As is normal, the guys stand around the fryer BS-ing and what-not. The conversation turned to my propane tanks, etc. My brother-in-law is a Project Manager for a large home builder and he essentially presides over the work crews when creating new sub-divisions. Masons, landscapers, framers, drywall guys, plumbers, electricians, roofers, etc. etc. He then ensure that everything is done correctly and on-time, plus deal with the customer complaints. Sounds like a crappy job, actually.

Anyway, I explained that normally, my propane tanks are used for tank-top radiant heaters in addition to 2 electric heaters and a kerosene, drum-style heater in my garage. I told him that I place a pedestal fan behind the kerosene heater to move the air and the other heaters are placed around the garage based on what I am working on. My heating units are not the result of a master plan but rather an evolution of things as I obtained them from various sources.

He told me that last winter, one of the houses they were building in a subdivision exploded and was leveled. While no one was seriously injured, the OSHA investigation concluded that the explosion was caused by incorrect, incompatible heating sources inside the house by the work crews. Apparently, one crew was using propane heaters and another was using kerosene heaters. According to OSHA, the post-combustion gases from a kerosene heat source and a propane heat source are combustible to each other. I have not bought completely into this idea yet but I was wondering - has anyone else heard of this?

I spent much of last winter working on my stock car with a kerosene/propane/electric mix of heat sources and had no problems other than excessive CO, but I dealt with that (as far as I can tell). It worked well enough that I am hoping to use it again this year. However, when I went out to warm up the garage this morning, I wimped out and only used the electric and kerosene heat sources.

...I want to avoid being "that guy" if this is actually has some basis in reality... I have a healthy suspicion of gov't agencies so I figured I'd post here and see what others think/know.

Thanks.

That sounds like a good question for the Mythbusters.

As long as you have proper ventilation, then it shouldn't matter what you are pumping into the air.

That is more or less what I was thinking. I don't really understand how uncombusted kerosene could somehow only be combusted by a propane heat source, or vice versa. Either the post combustion gases are flammable or not and in that instance, it would only take one heat source to cause an explosion...

But I am not willing to just take my own logic as gospel on this one, either.

Perhaps _incomplete_ combustion gasses, and/or leaks due to rough-handling of the equipment common in a construction environment contributed to a buildup of combustible gasses in the home that was set off by an ignition source (poorly-wired jumper wires for light sources, and/or gas water heater or gas stove ignition)? Today's homes are sealed up pretty tight, so there's an opportunity for gasses of any kind to build up and stay at pretty high levels for a long while. I think some of the kerosene heaters you have to pressurize the tank for them to work right, and I can see where the crew wouldn't bother depressurizing the tank at the end of the day.

I don't see kerosene and propane vapors combining to some form of mixture that would spontaneously-combust, as was hinted at here.

I'm looking for some heat source this year, too. I think I'll opt for one of the propane heaters. Luckily, though, I think my shop is big enough, and porous enough to keep much in the way of hazardous-levels of combustible gasses from building up. I'm still pretty paranoid about leaving the shop at the end of the day, and make sure things are turned off and secured. Interesting story, though, and it goes to show you, you can never bee too careful.