When used as directed, Aera is the safest air freshener available. All our fragrances are compliant with international and American inhalation safety guidelines. They also carry a certificate of compliance with the air freshener safety standards of the IFRA—the International Fragrance Association. Aera fragrances are completely free of alcohol and chemical propellants. The Aera device creates a fragrance effect with an ultra-low hypoallergenic quantity of fragrance materials in the air – a ratio less than 10ppm (parts per million) between fragrance molecules and air molecules.