This paper highlights the basic features of various ignition sources and some principles for prevention of ignition of potential explosible hydrocarbon gas atmospheres in industrial practice. Ignition by hot solid surfaces, heat from mechanical impact and friction, electric discharges and jets of hot gaseous combustion products is discussed in detail. The possibilities of effective ignition sources in industrial practice being generated by stray electric currents, cathodic corrosion protection currents, static electricity, lightning, high-frequency electro-magnetic waves, optical and radioactive radiation, ultrasonic radiation and heating by compression are discussed.