Using hand sanitizer is expected to produce a short-lived rise and fall in the Skyn data. These hand sanitizer “transients” have very large peak values. The shape of these transients are unique in that they rise and fall extremely quickly, faster than regular changes in transdermal ethanol secretion.
If it’s important to your application that the effects of hand sanitizer use are reduced, we’d recommend low-pass filtering your data to attenuate these fast-moving hand sanitizer transients. Note that a low-pass filter will also have smoothing effects on other parts of your data, so you must be mindful of how aggressively you design the filter. A lower cutoff frequency would make the filter more aggressive and begin to more heavily distort data other than just the hand sanitizer transients.