Methods

Methods

A total of 60 items were selected from three product categories: 20 each of bedding, outdoor apparel, and tablecloths and napkins. Products were purchased new in the fall of 2020 from 10 major retailers: Amazon, Bed Bath & Beyond, Costco, Dick’s Sporting Goods, Kohl’s, Macy’s, REI, Target, TJX, and Walmart. All labeled items were manufactured in Asia, with home furnishings made primarily in China as well as in India and Pakistan, and outdoor apparel made in Vietnam, Bangladesh, China, the Philippines, and Indonesia.

The bedding, tablecloths, and napkins selected included items marketed as stain- or water-resistant, as well as items that were not. All outdoor apparel was marketed as water- or stain-resistant.

We used two methods to investigate the presence of PFAS in these items. The first is total fluorine testing, which captures all PFAS and provides information about the total PFAS concentration. The second is compound-specific testing using mass spectrometry, which can detect a limited number of PFAS but provides information about the type of PFAS used. Concentrations of total fluorine are generally much higher than those of PFAS measured using compound-specific testing; the primary reason is likely that much of the PFAS content is in a polymeric form that is not measured. Since PFAS are a very large class of chemicals, non-polymeric PFAS that we are currently unable to measure may also be present.

Textiles were cut into samples by Toxic-Free Future using instruments cleaned with isopropyl alcohol and shipped to Galbraith Laboratories (Tennessee, USA) for measurement of total fluorine content using combustion with ion selective electrode; for most items this analysis had a detection limit of 10 parts per million (ppm). Besides the 60 original samples, we submitted six duplicate samples to Galbraith. Differences in all cases were minimal with the exception of a 47% difference in measurements in one item that had extremely high total fluorine measurements. Items with total fluorine content greater than 100 ppm were selected for analysis of specific PFAS analytes. Concentrations of a total of 51 PFAS were measured by Eurofins (Sweden) using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) after methanol extraction; the detection limit for these analytes ranged from one to 10 µg/kg.