Online Iodide Chemical Ionization Mass Spectrometry (I-CIMS) Enables Occupational Inhalation Exposure Assessment of 6:2 Fluorotelomer Alcohol (6:2 FTOH) Emitted to Air during Floor Waxing

Abstract

Fluorotelomer alcohols (FTOHs) are a class of per- and polyfluoroalkyl substances (PFAS) that have been reported in both indoor and outdoor air and are found in an array of consumer products, including waterproof textiles, fast food contact papers, and floor waxes. Time-integrated offline sampling methods for airborne FTOHs generally require sampling times of hours to weeks. Thus, integrated methods fail to capture the real-time dynamic behavior of sources, sinks, and exposure. Herein, we demonstrate the use of iodide chemical ionization mass spectrometry (I-CIMS) in capturing the real-time concentration dynamics of 6:2 FTOH in air during floor stripping and waxing in a university laboratory. Peak 6:2 FTOH concentrations during application of floor wax were 456.9, 406.3, and 263.2 ng m^–3, respectively, for three layers of wax (60 s averages). Additionally, the average 6:2 FTOH emission factor per wax layer was 5.10 ± 0.17 μg m^–2. We estimate a range of potential inhalation exposures from 1.6 to 460 ng kg^–1, depending on ventilation and workplace practices. Some 6:2 FTOH is expected to biotransform to three terminal acids (perfluorohexanoic acid, perfluoroheptanoic acid, and 5:3 fluorotelomer carboxylic acid), increasing blood serum concentrations of perfluorocarboxylic acids by an estimated 0.01–3.8 ng mL^–1 following application of three wax layers.