Fragrance
The part of a product that changes nothing about how it works, and the part most likely to be the reason somebody reacts to it.
In detail
Fragrance in a cleaning product is there for the user rather than the surface. It signals that a job has been done, it covers the smell of the actives, and it is a large part of how brands differentiate products that are chemically similar. None of it contributes to cleaning. It is nevertheless the constituent class treated most carefully by the labelling law. Perfume must be declared irrespective of concentration, and individual allergenic fragrance substances present above 0.01% by weight must be named specifically rather than hidden inside the word. That threshold is the useful thing on the label. A person who reacts to cleaning products often reacts to a fragrance component rather than to the surfactant or the bleach, and the named allergens are the only part of a formulation a consumer can actually match against their own experience.
Why
- Fragrance is explained by Adsorption of odour molecules
Sources for this page
Sources
Regulation (EC) No 648/2004 on detergents, Annex VII — labelling and ingredient data sheet
European Parliament and Council, as retained in UK law (legislation.gov.uk), 2004 · Government or regulator
Relied on for: That perfumes must be declared irrespective of concentration and that allergenic fragrances above 0.01% by weight must be named individually. (states this directly)
Safer Chemical Ingredients List — functional-use classes
United States Environmental Protection Agency (EPA), Safer Choice · Government or regulator
Relied on for: That the class is one of the functional-use classes a cleaning formulation is assessed in. (states this directly)