An Irritating Situation

After having work done on a residential HVAC system, the occupants of the house noticed they had an elevated degree of eye, nasal and skin irritation. Dust samples were collected from different rooms in the house and submitted for analysis.

When the samples were examined using Polarized Light Microscopy, the samples were found to contain very small fragments of fiberglass insulation. The small fragments were about 8 – 12 micrometers in diameter (1/4 the width of a human hair) and 20 – 750 micrometers in length. Some of the yellow adhesive which binds the fiberglass together can be seen on the fragments. These small friable fragments with sharp irritating ends were causing the undesirable itch and irritation.