Final answer:
In the event of a malfunction in the regulator of an S.C.O.C breathing apparatus (MSA 401 04 Survivair), the wearer would use an emergency breathing device known as a Spare Air.
Step-by-step explanation:
The wearer would use a spare air, an emergency breathing device, in the event that the regulator of a S.C.O.C. breathing apparatus (MSA 401 04 Survivair) malfunctioned. In an emergency, divers can use the Spare Air, a small, portable device that offers a backup air supply.
It has a mouthpiece or regulator, a small cylinder with compressed breathing air inside, and a pressure gauge to show how much air is left. The wearer can immediately switch to breathing from the Spare Air in case the primary regulator fails, protecting them.
It is important for divers to be trained in emergency procedures and familiar with the use of backup systems, such as the Spare Air, to ensure their safety and the safety of others in case of equipment failure.