By Steve Kerry Sensitivity is something that varies from one person to the next. Think of your body as a bucket, and each time you use a certain chemical you add a drop to that bucket. When it is full, your body can't tolerate that chemical any longer and it becomes hazardous to your health.
Some people have tolerance the size of a bathtub, other the size of a teaspoon.
There is no way of measuring your remaining tolerance level, and there seems to be no way of emptying the bucket. I'd been using cyano for a good 15 years, often leaning over the joint and getting a cloud of the fumes in my face when it kicked. The worse I ever got was sore eyes and a headache after an 8 hour building session. Last year I suddenly got short of breath. Couldn't figure it out, I was wheezing and gasping pretty bad.