Umahluko phakathi kweNqanaba B elinobungqina bokudubula kunye no-C

Udidi C lubonelela ngokhuseleko olomeleziweyo ngonyango oluchubekileyo olukhusela uqhushumbo.

Iqela lobushushu lezixhobo zombane	Ubushushu obuphezulu obuvumelekileyo bezixhobo zombane (℃)	Irhasi/ubushushu bokutshisa (℃)	Amanqanaba obushushu besixhobo esisebenzayo
T1	450	＞450	T1~T6
T2	300	＞300	T2~T6
T3	200	＞200	T3~T6
T4	135	＞135	T4~T6
T5	100	＞100	T5~T6
T6	85	＞85	T6

Uyilo lwe-flameproof lubonisa ukuthunga endaweni yezinto ezifakelwayo. Izixhobo zodidi C zibonelela ngemigangatho emide engatshiyo kunye nezikhewu ezicuthekileyo ezidubulayo. Ihydrogen, iacetylene, kunye ne-carbon disulfide ifuna ukusetyenziswa kweklasi ye-IIC, whereas other substances are adequately served by IIB class.