The search results provide information on fragrance and its effects on human health, as well as the ingredients or materials used in fragrances. Here are the key points:

• Fragrances consist of volatile chemicals with a molecular weight of less than 300 Da that humans perceive through the olfactory system.
• Fragrance materials vary from highly complex mixtures to single chemicals.
• A variety of consumer products such as candles, perfumes, personal care products, room fresheners, and detergents are commercially available with aromatherapy benefits.
• Fragrance formulations are considered a “trade secret” and therefore protected from disclosure – even to regulators or manufacturers.
• About 4,000 chemicals are currently used to scent products, but you won’t find any of them listed on a label.
• A single scent may contain anywhere from 50 to 300 distinct chemicals.
• Three-quarters of the toxic chemicals detected in a test of 140 products came from fragrance, reported a 2018 study of personal care and cleaning brands.
• The chemicals identified were linked to chronic health issues, including cancer.
• The fragrance industry says that even if many of their ingredients appear on hazardous chemical lists, safety boils down to a question of exposure.
• The exposure to any individual fragrance ingredient in a product is extremely low – well below 1% .
• The European Commission has published a list of fragrance substances that can act as prehaptens or prohaptens, forming new or more potent allergens by air oxidation and/or metabolic activation.
• The review also lists fragrance substances that are less frequently reported and thus less documented as consumer allergens.
• Graphite, a key ingredient in smartphone batteries, is mined in China and causes pollution that affects the health of villagers living near the mines and plants.
• Particulate matter, which includes the air pollutants emitted from graphite plants, is one of the critical groups of pollutants in the Chinese air.

In summary, fragrances are made up of a variety of chemicals, some of which can be harmful to human health. The ingredients or materials used in fragrances are often considered trade secrets and are not disclosed on labels. The European Commission has published a list of fragrance substances that can cause allergies. Graphite mining for smartphone batteries in China causes pollution that affects the health of villagers living near the mines and plants.