The Technegas derivative material named Pertechnegas ( Doug Mackey, Prince of Wales Hospital , Sydney Australia ) is produced when the usual pure argon environment of the Technegas generator, (MAGen - USA ) contains oxygen above 100 parts per million (ppm) by volume. For practical clinical purposes, a level of 2-5% oxygen is recommended, and gas filling companies have no difficulty meeting this requirement. But experiments from room air ( ~ 20% oxygen) down to 100ppm have been unable to discern any difference in the active species produced. Room air is not recommended as the high nitrogen content could possibly lead to oxides of nitrogen at the temperature (2550C) of the reaction.

The usual purpose for performing Pertechnegas studies is to measure the half-time clearance of the agent from the lung. It follows then that it is best to have the patient inhale the agent in as high a concentration as possible to minimise the number of breaths and therefore the time needed to acquire a useful count-rate. This will give the "sharpest" start point to the clearance curve. Thus it is not uncommon for the machine to be loaded with 550-740 MBq ( 15 - 20mCi) of pertechnetate for production of Pertechnegas. Since the actual activity delivered to the patient is governed by the count-rate level on the gamma camera as observed by the Technologist in the breathing manoeuvre, there should be no increase in patient dose in consequence.