Fragranced consumer products and effects on asthmatics: an international population-based study Abstract Asthma is an international concern, with risks linked to air pollutants. Fragranced consumer products, such as air fresheners and cleaning supplies, have been associated with health problems such as asthma attacks and breathing difficulties. This study investigates the health and societal effects of fragranced products on asthmatics in four countries: United States, Australia, United Kingdom, and Sweden. Nationally representative population surveys (n = 1137; 1098; 1100; 1100) found that, across the four countries, 26.0% of adults (n = 1151) are asthmatic, reporting medically diagnosed asthma (15.8%), an asthma-like condition (11.1%), or both. Among these asthmatics, 57.8% report adverse health effects, including asthma attacks (25.0%), respiratory problems (37.7%), and migraine headaches (22.6%), from exposure to fragranced products. In particular, 36.7% of asthmatics report health problems from air fresheners or deodorizers, 18.1% from the scent of laundry products coming from a dryer vent, 32.9% from being in a room cleaned with scented products, 38.7% from being near someone wearing a fragranced product, and 37.5% from other types of fragranced products. For 24.1% of asthmatics, health problems from fragranced products are potentially disabling. Further, 20.6% of asthmatics have lost workdays or lost a job, in the past year, due to fragranced product exposure in the workplace. Fragrance-free environments received widespread support. More than twice as many individuals, both asthmatics as well as non-asthmatics, would prefer that workplaces, health care facilities and professionals, airplanes, and hotels were fragrance-free rather than fragranced. This study provides evidence that asthmatics can be profoundly, adversely, and disproportionately affected by exposure to fragranced consumer products. Moreover, the study points to a relatively straightforward and cost-effective approach to reduce risks; namely, to reduce exposure to fragranced products.