So what does 40/42 mean? Yes, this is 100% pure lavender essential oil and it is all from France, but it might be from two or more harvests – a different field, even a different year. The 40/42 refers to the balance of Linalool and Linalyl acetate esters, which is what gives it such a consistent floral scent but also means it is standardized. This means it should ALWAYS smell the same. It is also not recommended for therapeutic use because it's always a blended product. For therapeutic use, stick with Lavandin Grosso, Bulgarian lavender, or California lavender– all great choices.