Can laundry detergent cause or worsen allergies?

What's actually in it

Laundry detergents contain surfactants, enzymes, fragrances, optical brighteners, and preservatives. These chemicals remain on fabric even after rinsing. You then wear the fabric, sleep on it, and breathe the residue all night. Some of these chemicals irritate airway tissue directly. Others change how the immune system responds to allergens like pet dander and pollen.

Scented detergents and fabric softeners are the worst offenders. The fragrance chemicals they use are often sensitizers themselves.

What the research says

A 2026 study in Allergy found that laundry detergents enhanced sensitization to co-inhaled allergens and made allergic airway inflammation worse. The detergent chemicals acted as adjuvants, meaning they amplified the immune response to other allergens already in the environment. People exposed to detergent residues developed stronger allergic reactions to things they were already sensitive to.

The effect was specific to the detergent chemicals, not just the physical act of washing. Unscented, enzyme-free detergents in minimal doses had less of an effect.

The safest bedding is washed with fragrance-free, dye-free detergent and made from natural fibers. Organic cotton home goods need less detergent to clean and hold fewer chemical residues than synthetic fabrics.