Smartfuel features flame arrestor in the neck of the bottle to provide additional safety against possible flash-fire when transferring fuel from the bottle into the fireplace reservoir.Smartfuel is "Planet-Friendly and suitable for use indoors or outdoors, as no harmful fumes are generated when burning - only small amounts of CO2 and Water Vapor"_ no soot, no smoke, no smell, and no residue. The only recycled ethanol fuel available, making it the world''s ''Greenest Choice EthanolSmartfuel contains BITR, a bitterant to prevent accidental ingestion by children and small animals.Smartfuel is Laboratory Tested and Certified for both it''s Safety Pour technology, and it''s clean, toxic free exhaust for indoor burning... providing consumer ''peace of mind''. Laboratory Certification & MSDS are available online.Smartfuel: Your safety is our first concern.Never pour fuel into a lit fire or into a burner that is near a source of ignition.Never pour fuel onto hot surfaces. Allow burners to cool at least15-20 minutes (cool to the touch) before refilling.Store Smartfuel in a cool place, away from direct sunlight or heat source.Never let children handle fuel or operate fireplace or burner.Always read & follow manufacturers operating and safety instructions prior to use in addition to all instructions and warnings that accompanied your fireplace.We do our best to ensure your safety by delivering our fuel in the safest possible package while providing as much safety information as possible; on the label and on our website. But in the end, it is You, the User, that must use this dangerous fuel in a safe and responsible manner. Be very cautious and use common sense.Failure to follow safety instructions may lead to serious injury or death.While the flame provided by burning the fuel is highly decorative and beautiful, it also is efficient in providing heat however it cannot be recommended or considered as a main heat source.Due to the ventless nature of the fireplaces themselves; no heat is lost up the flu or vent. Depending upon the size of the fireplace, the fire can provide up to 8,500 BTU/hour of heating energy. This is enough energy to heat approximately 375 sq ft of living space.One quart of fuel will burn up to 5 hours dependent upon the fireplace size and adjustment of the opening of the lid over the flameEach bottle will produce 21,000 BTU, so depending on how you adjust the damper on your burner you can adjust burn time and heat output.Smartfuel is Made in the USA.