Is fragrance bad for skin?

It does nothing for skin and carries a small but real risk of allergy or irritation, so it is a trade rather than a rule. Most people wear it without trouble; if your skin is reactive or your barrier is compromised, it is the easiest thing to remove first.

Does fragrance-free mean the same as unscented?

Not reliably. Neither term has one definition everywhere, and unscented often means a masking fragrance was used to cover the smell of the base rather than that no scent material is present. The list is more informative than the front of the pack.

Is natural fragrance gentler than synthetic?

No. Allergen declaration rules attach to molecules, not to where they came from, and several of the most frequently declared ones arrive mainly through essential oils. A plant origin is a fact about sourcing, not about tolerance.

Why does the label only say Parfum?

Because most markets let a fragrance compound be declared as one term, treating its composition as a trade secret. The separately named allergens beside it are the only window the list gives you.

My product smells different but the ingredients are unchanged.

The compound behind the word can be reworked or bought from a different supplier without the list changing at all. If it is also behaving differently on your skin, treat it as a new product and patch test it.

Parfum (Fragrance) — Ingredient Guide

How it works

Parfum is not a substance. It is one INCI term standing in for a blend of scent materials, often many, supplied to a brand as a single compound and declared under one word, because in most markets a fragrance's composition is treated as a trade secret. Where the rest of a list names things, this names a mixture, and the mixture differs from product to product.

Some of what it covers is synthesised, some distilled or pressed from plants, and the term does not distinguish. Its job is smell: either the scent a product is sold on, or the masking of a base that surfactants, oils and some actives leave smelling unpleasant. That is why a product described as unscented can still carry it.

The evidence

Fragrance materials are among the most commonly identified causes of allergic contact dermatitis from cosmetics. That is why individual fragrance allergens have to be named separately once they pass a set level: the rule exists because the umbrella word hides the molecules people actually react to. Which molecules those are, and the level that triggers naming them, is decided by each market and has been revised more than once, so the current local rule is the one to read.

The rest is less dramatic. Fragrance is not toxic at the levels used, most wear it without incident, and irritation depends on the dose, on the rest of the formula and on the barrier it lands on. The honest summary is a trade: it does nothing for skin and carries a risk that is small but not zero. Whether that is a bad deal depends on how much you want the product to smell of something, which is not an irrational thing to want.

Suitability

Not an active; no skin type argues for its presence
A specific reason to avoid it if patch testing has named a fragrance allergen
A general one where skin is eczema-prone, broken or freshly exfoliated
Fragrance-free and unscented are different claims, and the second can mean masked

Concentration

No figure, and one would not travel. The level is set by the brief and by whatever safety assessment the market requires of the finished product. A fragrance strong enough to notice is not automatically a problem, and a trace used to cover a base is not automatically safe for someone already sensitised: the amount matters less than whether your skin has met that molecule before.

Conflicts & combinations

Nothing conflicts with it chemically. Two practical points. A routine can carry fragrance at every step, and exposure adds up even where no single product is heavy. And the word is stable while the thing behind it is not: a brand can change supplier or rework the compound with no visible change to the list, which is why a product can start smelling different, or start stinging, while its ingredients read as before.