In regards to your inquiry- phototoxicity is mostly associated with citrus oils that contain certain naturally occurring constituents like furanocoumarins that cause a skin reaction when exposed to UV light. Not all citrus oils are phototoxic, and how they are extracted can also play a role. Additionally, lemon and lime oils that are steam distilled rather than cold or expeller pressed are generally considered not phototoxic. Finally, sweet orange, blood orange, mandarin and yuzu oils are not considered phototoxic.