Baptiste Bouygues, the co-founder of new natural perfume line ORMAIE Paris, adds that these ingredients will likely get lighter or darker, especially when they’re exposed to variations in sunlight or temperature. “It takes a few months to happen… When you work with natural ingredients, it is normal for things to evolve.” So in the same way you’d store an essential oil blend in a dark amber bottle to preserve its properties for longer, keeping your perfume out of direct sunlight in a cool, dark place will help it last longer. While you won’t find these listed on a label, they can be lumped into the “fragrance” umbrella. According to the U.S. FDA2, individual ingredients in fragrances don’t have to be disclosed on the label since they can be considered trade secrets. When you see “parfum” or “fragrance” listed on the label, keep this in mind and dig a little deeper. “Look for information specifying that the fragrance is derived from essential oils, absolutes, etc. Beware of the term ’nature identical’—it means it’s an aroma chemical found in nature but synthesized in a lab,” cautions Krystal Quinn Castro of California-based perfume brand Los Feliz Botanicals. And let this wonky loophole be a lesson for the next time you’re in the market for a new scent: Shapiro recommends looking for one that is compliant with the rules around the world, not just in the notoriously lax U.S. market, and certified safe by a reputable source, such as the International Fragrance Association. Moral of the story: Judge a perfume not by its color but by its ingredient list and certifications. Emma received her B.A. in Environmental Science & Policy with a specialty in environmental communications from Duke University. In addition to penning over 1,000 mbg articles on topics from the water crisis in California to the rise of urban beekeeping, her work has appeared on Grist, Bloomberg News, Bustle, and Forbes. She’s spoken about the intersection of self-care and sustainability on podcasts and live events alongside environmental thought leaders like Marci Zaroff, Gay Browne, and Summer Rayne Oakes.