Isolation & Communication

Isolation

Isolating a confined space is a process that removes the space from service by:

§  Locking out electrical sources, preferrably at disconnect switches remote from the equipment.

§  Blanking and bleeding off pneumatic and hydraulic lines.

§  Disconnecting belt and chain drives and mechanical linkages on shaft-driven equipment where possible.

§  Securing mechanical moving parts within confined spaces with latches, chains, chocks, blocks, or other devices.

Communication

Effective communication among entrants, attendants, and supervisors is essential and must occur continuously to be effective. It is critical to have the correct communications equipment for the space being entered. Workers inside have to be able to communicate among themselves, as well as with the attendant outside of the work space. In the event of an emergency, communications equipment allows help to be summoned quickly.

Effective communication can take many different forms.

§  Voice communication is highly effective when distance and noise levels permit. If the distance is too far or the noise level too loud, other methods must be used to maintain contact.

§  Hand signals can be used effectively if the entrant and the attendant are able to maintain visual contact.

§  Hard wire communication and hand radios can also be highly effective.

§  Because of normal movement, rope pull signals are not recommended. Ropes can also be ineffective if the entrant becomes incapacitated and is not able to signal in the case of an accident.

All workers involved in a confined space entry should be knowledgeable about the communication equipment and trained in its use. Testing needs to be done routinely prior to space entry as well as immediately after entry. All communication equipment must be intrinsically safe, especially in flammable atmospheres.