Glade PlugIns: 50+ Fragrance Chemicals Disclosed, Including the Ones That React With Indoor Air to Form Formaldehyde
SC Johnson voluntarily names every fragrance chemical. The story is what those chemicals do when ozone is in the room: terpene oxidation produces formaldehyde, a Group 1 carcinogen.
Glade PlugIns Scented Oil is the transparency outlier in this category, SC Johnson voluntarily discloses individual fragrance chemicals on its ‘What’s Inside’ portal, unlike P&G’s single-word ‘Fragrances.’ The irony is that full disclosure makes the chemistry visible: limonene and linalool are present in multiple Glade variants. Both react with indoor ozone to form secondary pollutants including formaldehyde, an IARC Group 1 human carcinogen, and secondary organic aerosols. Steinemann (2011) confirmed limonene + ozone → formaldehyde in a peer-reviewed study. A 2017 chamber study cited by Steinemann found a plug-in air freshener driving formaldehyde to 28.2 μg/m³. In a ventilated room this matters less; in a closed bedroom where a plug-in runs overnight, it’s the whole story.
The label, flagged
Dipropylene Glycol
carrier solvent
PPG-2 Methyl Ether Acetate
carrier solvent
Fragrance (complex mixture)CAUTION
Not a hazard in itself, but a legal black box. “Fragrance” can shield ingredients (including EU-banned ones) that you are never told are there.
50+ individual chemicals disclosed on SC Johnson What’s Inside portal
LimoneneCAUTION
Harmless fresh, but it oxidizes in air and on skin into potent contact allergens. Real, measurable sensitization; not a cancer scare.
EU-named allergen; reacts with ozone to form formaldehyde
LinaloolCAUTION
Same story as limonene: weak on its own, a real sensitizer once oxidized. Common cause of fragrance contact allergy.
EU-named allergen; ozone-oxidation secondary pollutant precursor
CoumarinCAUTION
A recognized fragrance allergen present in most deodorants. Sensitization is real but bounded; no credible cancer signal at cosmetic exposure.
EU-named allergen; present in Apple Cinnamon variant
GeraniolCAUTION
One of the most frequently reported fragrance contact allergens in EU clinics.
EU-named allergen; present in floral variants
Citral
EU-named allergen; lemon/citrus note
Vanillin
fragrance; vanilla note
Eugenol
EU-named allergen; clove/spice note, Apple Cinnamon variant
Source: SC Johnson What’s Inside portal (Aqua Waves, Clean Linen, Apple Cinnamon variants). View label. Tap any flagged ingredient for the evidence.
What to use instead
The fix isn’t complicated: a fragrance-free or fully-disclosed alternative, with the ingredients flagged on this label designed out, closes these gaps at once. We pick the ones worth your money.
See cleaner picks →Editorial analysis of the publicly listed label and regulatory/peer-reviewed sources. Not medical advice, not affiliated with the brand. Verdicts are evidence-graded, we flag what the data flags and clear what it clears.