Risk assessment of RF radiation ignition hazard

Electromagnetic waves produced by radio-frequency (RF) transmitters (e.g. radio, television, cell phone and radar) will induce electric currents and voltages in any conducting structure on which they impinge. If this happens in a location where a potentially flammable atmosphere is present, a hazardous situation can occur. However, the possibility of ignition will depend on many factors, particularly whether the spark can deliver sufficient energy to ignite a particular flammable atmosphere. In this paper, an attempt has been made to present the likelihood of ignition of fuel and solvent vapors due to the presence of RF transmitters, inadvertent ignition of Electro Explosive Devices (EEDs), explosives and to recommend the limits for use of mobile phones during Handling, Assembly and Integration of Rocket motors and also during Flight trials. The frequency range covered is 9 KHz to 60 GHz. Ignition of flammable atmosphere has been assessed as per British Standard BS 6656:2002. Inadvertent ignition of EEDs is also assessed as per US Army “Explosives Safety Standard”. As a result, safe distances have been arrived at and reported in the present work.