Starting in 2009, I noticed that many electronics caused both stinging and numb pains in my hands, arms, and face. I initially thought these were problems with plastics or paints, but later narrowed it down to the circuit boards inside the products. PCBs manufactured 2008 and earlier were fine, then something changed in 2008-2010; my best guess is that newer PCBs produce a large number of fiberglass particles ("The glass fibers had diameters of 11–16 μm"). This is just my guess; there may be other factors like changes in solder and the PCB washing process.

The stinging is sometimes painful, as if the particles interact directly with the nerves. Washing my hands helps after exposure, but random stinging can persist for about two days. The particles seem small enough to migrate a small distance into the hand and start causing numb pains instead of sharp stinging pains.

This is not RSI, switching to devices with older PCBs makes the problem go away.

Please email me ( if you have any information or are also affected.

Known-bad products

Known-good products