Overview

• A Purdue University study published in Environmental Science & Technology used realistic indoor routines with participants’ own straighteners, curlers and wavers to measure emissions.
• A 10–20 minute styling session produced upward of 10 billion nanoparticles deposited in the lungs, an exposure comparable to standing in dense motorway traffic.
• Particle emissions spiked when appliance surfaces exceeded about 150°C, rapidly generating large numbers of new airborne nanoparticles.
• Leave‑in, heat‑resistant sprays, creams and gels produced especially high emissions when heated during styling.
• The study highlights D5 siloxane as a compound of concern under European scrutiny and urges better ventilation, limited product use and avoiding heat with such formulations.