a. The density of neutral gas density around a spacecraft due to neutral gas emission shall be analysed and an assessment made of the risk of the triggering of discharges by the gas.
NOTE 1 The reason is that ESDs can be triggered on charged surfaces at potentials below the level at which they would normally occur due to the emission of neutral gases e.g. from chemical or electric propulsion systems.
NOTE 2 An example is during thruster firings.