Our friends at Earth Techling.com posted recently about a Nu-Flame BioFireplace Provides Cozy Alternative To Wood And Gas. They write:
The flame is powered by clean-burning liquid bio-ethanol fuel which the company sells separately. According to Nu-Flame, their denatured bio-ethanol is a safe fuel made from 100 percent organic waste material right here in the USA. Using this fuel in the fireplace guarantees that you won't be breathing in soot, smoke or hazardous fumes, and the bottles are made with 30-40 percent recycled material.
Unlike wood or gas burning fireplaces, these portable units have no flue, so any products of combustion are going to stay in the room, particularly in modern tightly-sealed homes. I asked TreeHugger Emeritus chemist John Laumer about it a few years ago, and he told me that "alcohol molecules are very short and produce very little CO2 compared to any other hydrocarbon liquid. Much of the liberated energy is from hydrogen combustion."
In other words, it uses oxygen from the air to produce water vapour and a little CO2. Their safety warning says "Do not burn in a confined space, the flame consumes oxygen." the downloadable safety notice goes further:
This fireplace will use oxygen from the air inside the room where it is operated. The rooms should be well ventilated with enough oxygen and fresh air being supplied (i.e. slightly open windows if room is not vented). When ventilated, the room where the fireplace is operated in should not be smaller than 215sq.ft. (to calculate the square footage of a room multiply the width x length. For example, If the room is 15’ wide x 16’ long then 15’ x 16’ =240 sq.ft.) Freestanding and tabletop units must be placed on a safe, level, stable, non-flammable area.
I wonder how many people buying these things have a room that big.
There are probably some other products of combustion or substances added to the air; According to the Material Safety Data Sheet, the fuel is 90% ethyl alcohol, with some proprietary ingredients (I hate it when they say that) and Denatonium Benzoate, a very bitter chemical added to make it impossible to drink.
As for being safe, there are degrees. The MSDS clearly says that when handling:
Ventilation: Good general ventilation is sufficient. Avoid inhalation of vapors.
Respiratory protection: NIOSH approved respirator should be worn.
Skin Protection: Avoid skin contact. Wear rubber gloves.
Eye Protection: Avoid eye contact. Wear safety glasses with splash guards or goggles.
In other words, if you are following the recommendations of the material safety data sheet provided by the manufacturer of the stove and available on its website, you should fill the fireplace while wearing a respirator, rubber gloves and goggles. But it's safe!
You don't burn stuff in a healthy home.
The fundamental principle that I think should be followed is that you don't burn stuff without an exhaust or a flue; There is enough crap going our air already and oxygen is nice to have. Another principle is that you try to avoid bringing toxic and extremely flammable chemicals into your house if you can; a principle of healthy living is that if you can't drink it, you don't bring it in. Finally, you don't put serious burn hazards loose on your coffee table; people trip, things happen.
Clean air, and safe, non toxic products are green. This is not.