Yes. People can be allergic to any ingredient, even if it is 100% natural.

For example, our popular Lavender & Chamomile Aroma Mist has chamomile essential oil which is extracted from the chamomile plant. Chamomile is part of the Compositae family; thus, patients who are hypersensitive to the Asteraceae/Compositae family, which includes ragweed, chrysanthemums, marigolds, daisies, and other herbs, should be alert for potential allergy symptoms.