Brian, these have been around for years and are designed for everyday home use. These are certified for full time home use. There should always be concerns about safety when using any kind fire in a home. This includes gas stoves, wood stoves, gas or oil lamps, Rocket Mass Heaters, fire places, pellet stove, and any other fire breathing stove or furnace. I have a CO2 monitor for safety because I have a fire place and a pellet stove. They are recommended along with a smoke detector even if you don't have a fire breathing device for safety.
The bottom line is you want something that is safe and dependable. Something that will protect your pipes from freezing while you are gone.