Aroma refers to the scent or odor of a substance, and it can be either good or bad depending on the source of the aroma or flavor. Aroma compounds are chemical compounds that have a smell or odor, and they must be sufficiently volatile for transmission via the air to the olfactory system in the upper part of the nose. Here are some key points about aroma and fragrance:

• Ingredients or materials: Fragrances are substances possessing strong-smelling organic compounds that have characteristic, pleasant odors. They are used in many products as a perfume, including cosmetics, toiletries, household, laundry, air fresheners, candles, and incense products. Fragrances can be derived from natural or synthetic methods, and they can be processed differently for purity. "Fragrance" or "Parfum" on an ingredient list is not technically an individual ingredient or chemical but rather an umbrella term that refers to all the compounds and chemicals that comprise a products fragrance.

• Positive effects: Aroma can have a significant impact on human psychophysiological activity, including mood, stress, and working capacity. Fragrances are used in aromatherapy to provide benefits such as relaxation, stress relief, and improved mood.

• Negative effects: Some fragrance ingredients, especially phthalate ingredients, have raised concerns about potential negative long-term health effects. However, research does not show that exposure to a limited amount of phthalate ingredients, including fragrance ingredients, will cause harm.

In summary, aroma refers to the scent or odor of a substance, and fragrances are substances possessing strong-smelling organic compounds that have characteristic, pleasant odors. Fragrances are used in many products as a perfume, and they can have positive effects on human psychophysiological activity. However, some fragrance ingredients have raised concerns about potential negative long-term health effects.