Marble ethanol fireplace manufacturers tell you that biomass ethanol fuel, a plant-derived fuel made by fermenting sugar from corn, potatoes, and cellulose, is considered a "clean fuel." It doesn't contain dangerous chemicals, and in some cases, it's made from forestry by-products such as wood pulp and sawdust.

By burning cleanly and efficiently, Marble ethanol fireplace's biomass ethanol fuel produces only small amounts of carbon dioxide and water as by-products.
Properly used ethanol fireplaces are safe. Its fuel, biomass ethanol, is flammable. The way you pour it into the fireplace for refueling can cause a spill. Should this occur, the spilled material could pose an unexpected safety hazard.
The flame generated by the Marble ethanol fireplace consumes oxygen and produces carbon dioxide. For most rooms, this is perfectly acceptable. But avoid placing an ethanol fireplace with a high BTU index in a small space as it may produce too much carbon dioxide to be safe.
The biomass ethanol fuel of the ethanol fireplace itself produces a steady flame without sparks or smoke, ash. Be sure to follow all instructions on the Marble ethanol fireplace itself, add fuel, and extinguish flames to avoid potential burns or other hazards.