Fiberglass and Other Flame-Resistant Fibers in Mattress Covers

Abstract

Public complaints have raised concerns that some mattresses in the current marketplace may be potential sources of airborne fiberglass. Although mattress foam is often marketed as chemical-free, their cover compositions are not as well understood by the general public. To fill these basic information gaps, the covers of four newly purchased mattresses were sampled and analyzed using polarized light microscopy, SEM-EDS, and FTIR microspectroscopy. Two of the mattress covers contained over 50% fiberglass in their inner sock layers. Up to 1% of the fiberglass had migrated to adjacent fabric layers, representing a potential risk of consumer exposure if the zipper on the outer cover is opened. The observed fiberglass fragments had calculated aerodynamic diameters ranging between 30 and 50 µm, suggesting they are potentially inhalable into the nose, mouth, and throat, but are likely too large to penetrate deeper into the lungs. No fiberglass was observed on the brand new mattresses' outer surfaces. Synthetic fibers also present in the sock layers were consistent with flame resistant modacrylic containing vinyl chloride and antimony. The use of fiberglass and other chemicals in mattress covers poses a potential health risk if these materials are not adequately contained. The apparent non-inclusion of mattress covers in chemical-free certifications suggests that further improvements are needed in mattress labeling and education of consumers.

Keywords: exposure assessment; fiberglass; flame retardants; mattresses.

Figure 1

Main components of each tested mattress and observed compositions.

Figure 2

Low-power reflected-light stereozoom microscope images of FG-1 mattress subsamples acquired at 10×. (a) Synthetic, woven outer cover material from top side of mattress. (b) Synthetic, fibrous mat beneath outer cover material from top side of mattress. (c) Synthetic, woven outer cover material from side of mattress. (d) Outer cover material from bottom of mattress with fibrous mat, foam coating, and woven fibers.

Figure 3

Low-power reflected-light stereozoom microscope images of FG-2 mattress subsamples acquired at 10×. (a–c) Three sections of the synthetic, woven outer cover materials, including fiber-filled bead (b). (d) Inner cover material with natural, woven fibers.

Figure 4

Low-power reflected-light stereozoom microscope images of FG-3 mattress subsamples acquired at 10×. (a) White, synthetic, woven outer cover material from top side of mattress. (b) Beige outer cover material from bottom side of mattress consisting of synthetic fibers in polymeric binder. (c) Inner sock material, showing woven threads, each uniformly wrapped in white synthetic fibers. (d) Same as (c), but inner fiberglass core revealed inside each thread.

Figure 5

Low-power reflected-light stereozoom microscope images of FG-4 mattress subsamples acquired at 10×. (a) White, synthetic, woven outer surface of outer cover material. (b) White, synthetic inner plastic sheet surface of outer cover material. (c) Inner cover material consisting of synthetic fibers in polymeric binder, and short straight fiberglass fibers sticking into surface (indicated by arrows). (d) Inner sock material, showing woven threads consisting alternately of white synthetic fibers and shiny/clear fiberglass bundles.

Figure 6

(a) Fiberglass (straight) in FG-3 inner sock material with synthetic fibers (wavy) (100× PLM). (b) Rare fiberglass fragment in FG-3 bottom, outer cover material (100× PLM). (c) Fiberglass in FG-4 inner sock (80× stereozoom). (d) Fiberglass shed onto foil surface after FG-4 inspection (10× stereozoom). (e) Fiberglass in FG-4 inner cover material with synthetic fibers (100× PLM). (f) Higher magnification of fiberglass morphology from FG-4 inner sock (400× PLM).

Figure 7

SEM-EDS from FG-3 inner sock. (a, b) Cut bundle of fiberglass wrapped in synthetic fibers. (c) One fiberglass fiber and two synthetic fibers with characteristic bright regions. (d) EDS acquired from fiberglass region marked in (c) showing Si, Al, and Ca. (e) EDS from bright spot in synthetic fiber marked in (c) exhibiting Cl and Sb.

Figure 8

SEM-EDS from FG-4 inner sock. (a) Cut bundle of fiberglass and separate bundle of synthetic fibers. (b) Single fiberglass fibers with blunt ends and 8 um thickness. (c) Fiberglass fibers and synthetic fibers. (d) EDS acquired from fiberglass region marked in (c) showing Si, Al, and Ca. (e) EDS from bright spot in synthetic fiber marked in (c) exhibiting Cl and Sb.

Figure 9

(a) FTIR microscope image of analyzed area of 200 um thickness, synthetic fiber bundle from inner sock material in FG-4. (b) FTIR microspectroscopy results (red spectrum) from (a). Also shown is a spectrum from the inner sock of FG-3 (orange). Both are good matches with the library spectra for modacrylic fibers containing vinyl chloride and antimony trioxide additives (blue). In addition, the synthetic fibers from FG-3 contain minor peaks matching PET (green).