INCI name
Benzyl Alcohol
Also listed as: A preservative and a fragrance component
Benzyl alcohol is used in two ways. It is a preservative in some water-based products, often alongside other preservatives such as dehydroacetic acid. It is also a constituent of many fragrance compounds and of some essential oils, and in the EU and UK it is one of the fragrance allergens that must be listed by name above a threshold.
Seeing benzyl alcohol on a "fragrance-free" product usually means it is there as a preservative, not as a scent, but the molecule is the same. People with a diagnosed benzyl alcohol allergy need to avoid it in both roles.