CommonCense Candles will emit its fragrance throughut the life of the candle. These candles will burn approximately 60-80 hours, sometimes longer, when burned properly by extinguishing every two hours and trimming the wick to 1/4 inch. These candles contain lead-free wicks. When you are not burning the candle, you may leave the lid off as it will continue to act as a room deodorizer. Since some fragrances are stronger than others, you will notice the aroma from some of them will not only fill the room its in, but most adjoining rooms as well.