Emission is composed almost completely of water vapor and CO2 (carbon dioxide); the amount of CO2 emission from Ethanol Flame is comparable to that of two medium-sized candles. The other components emitted are negligible in quantity well under any limits. The other hazardous substances of combustion such as monoxide, stockoxide and aldehyde are not released until a combustion temperature of 700°C; the temperature of the bio fireplaces is under 400°C.