For a conventional mechanical altimeter on which you adjust the datum by moving the sub scale, the most used standard says they should be adjustable ~950mb to ~1050mb, so anywhere between -1,000’ and 2,000’ pressure altitude. Electronic ones have a wider range, I believe from ~750mb to ~1050mb, which would still cause problems trying to set QFE over 8,000' airfield elevation, like Bogata and many other airports in South America and China.