Apparatus Group

There are two apparatus groups for gas/vapour environments:

Group I covers the use of equipment in underground mining environments where methane is present.

Group II covers all other environments

Group II is further divided into subgroup IIA, IIB or IIC:

• IIA - propane (least incendiary)
• IIB - ethylene (more incendiary)
• IIC - hydrogen and acetylene (most incendiary)

Apparatus Groups are sometimes referred to, erroneously, as ‘Gas Groups’.