IMO if it's be used indoors I would pay the extra for the clean burning stuff. Out in the garage I can tell when my propane heater has been running for a couple hours, and that's something that burns cleanly (has an O2 shutoff, so I don't think it's CO/CO2 related). Outdoors is different.
Call me crazy but I think I'd rather spend my money on a battery of some sort and an LED light instead. D cells can be stored for a number of years, and have large capacity. Some of the large fancy candles (in glass jars) are relatively "safe" and can be counted on for low level lighting around the house. But don't make enough light to ready by. I'm not sure what your goal is, just one light to get by with, or something to weather a multi-day outage?
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Something I have grown to absolutely love are headlamps, the sort that you strap onto your head--it's like they can read your mind and will automatically put the light where you need it.
Like
this. These days I don't work on my car without it... and during the last outage, when I was rewiring the panel so as to change circuits so as to bring certain outlets online, very very useful. [That reminds me, I need to buy a spare, if not three, just that handy.