Caution has to be used in refueling burners because ethanol is volatile, transparent and odorless
When the refilling takes place directly in the burner, it is difficult, in case of overflow to clean it up and to make sure that no spillage has occurred.
Sparxs successfully developed and patented a removable refillable tank and/or a single use refill cartridge to avoid the risk of overflow and spillage (main cause of accidents and users errors) by making sure that refueling is done away from the fireplace ( a well lit kitchen sink ?).
*Experience shows that using a liquid pump does not lower significantly the risk of overflow or spillage. The CSC (Commission for Security of Consumers) advises against the use of electric liquid pump.