Effects of fragrance and essential oils for those with allergies, asthma and exotic bird owners can be serious. Exotic birds kept in the house breath in the scent which effect the breathing due to the small lung capacity. This also has an effect on humans as well especially those with asthma and must be avoided. For humans we strongly recommend unscented dye-free. With this said, we advise NO burning of candles, air fresheners or diffusing of scent whatsoever in the home.