Scented candles, while pleasing to humans, have only been tested for safety on the humans who buy them. No studies have been done on potential harmful effects of scented candles on animals. Animal care experts agree, however, that scented candles should be used with caution around animal members of the family.
Scented candles may contain pollutants like benzene, toluene, formaldehyde and carbon dioxide, which are released into the air when the candle is burned.
Candles may also release particles containing soot and metal when they are burned, which may become lodged in the lungs when inhaled.
Effect on Mammals
According to the Animal Poison Control Center, scented candles should not pose a risk to dogs and cats so long as they are burned in a properly ventilated room.
Effect on Birds
Both the Animal Poison Control Center and the Long Island Parrot Society agree that candle scents may pose a risk to birds, as birds have complex respiratory systems that are sensitive to fumes.
Because household products are rarely tested on birds, it is best to exercise caution when using household chemicals around birds. Birds should never be kept in the same room as a scented candle.