This European Prestandard specifies the control functions of electric and electronic controls that are used to prevent unsafe operation of gas burners and gas burning appliances. For this purpose this European Prestandard specifies methods for the assessment of function blocks with regards to their fault behaviour and preventative measures. Function blocks which are not covered by dedicated control standards (see annex A) are within the scope of this prestandard. An electric or an electronic device which contains a control function is based on the principle that it provides the same safety level as other technologies (e.g. mechanical solutions).