Always check your withholding with this tool if there are personal or financial changes in your life that might change your tax liability, for example new employment or a promotion changing income amount, or new family members altering the number of dependents you claim.
believe the answer you're looking for has to do with the pressure-altitude-voltage derating related to corona discharge, which increases (gets worse) with higher altitude and peaks at around 80-100,000' Typically this is considered to occur at votlages above 300 V peak, but be sure you are accounting for all transients and internal voltages.
Environmental and health effects of nitrogen oxides. Elevated levels of nitrogen dioxide can cause damage to the human respiratory tract and increase a person's vulnerability to, and the severity of, respiratory infections and asthma. Long-term exposure to high levels of nitrogen dioxide can cause chronic lung disease.