The Risk Management Tool Box Blog

The United States Occupational Safety and Health Administration (OSHA) defines, in its general industry rule, a confined space as having three attributes:

1. Large enough to enter and perform work;
2.  Limited access and egress; and
3. Not designed for continuous occupancy.

Australian Standard (AS2865-2001) defines a confined space as:

“An enclosed or partially enclosed space that is at atmospheric pressure during occupancy and is not intended or designed primarily as a place of work; and

a)                 Is liable at any time to:

i. Have an atmosphere which contains potentially harmful levels of contaminant;

ii. Have an oxygen deficiency or excess; or

iii. Cause engulfment; and

b)           Could have restricted means for entry and exit.

The United Kingdom Health and Safety Executive (UK HSE) says:

“It can be any space of an enclosed nature where there is a risk of death or serious injury from hazardous substances or dangerous conditions (e.g., lack of oxygen)”.

Obvious confined spaces include:

»           Tanks;

»           Stacks;

»           Tunnels; and

»           Trenches.

Some less obvious confined spaces include:

»           Rooms which are inadequately ventilated;

»           Shrouded columns or vessels which render them ‘air tight’;

»           The roof of floating roof tanks; and

»           Rooms and areas that become confined spaces by virtue of the activities being undertaken.

In all cases, confined spaces are particularly dangerous because they may frequently:

»           Contain or have the potential to contain an hazardous atmosphere;

»           Contain a material that has the potential for engulfing the work party;

»           Have an internal configuration that might cause an entrant to be trapped; or

»           Contain other recognized serious safety or health hazards.

Because confined space work can be so dangerous, there are a number of safety-critical controls that need to be applied to all confined space entry activities.  The safety-critical controls are highlighted below:

1. Identify the hazards using the Think 6, Look 6 process;

1. Once hazards are identified, search for ways of eliminating or isolating them;

1.  In addition, always consider eliminating the confined space entry activity;

1. If there are no alternatives to confined space entry, always test for presence of gas;

1. Remember to continuously gas monitor atmospheric conditions;

1. Always ensure that confined space entry  is controlled by an authorized “Permit to Work”;

1. Ensure workers performing confined space entry work are suitable trained;

1. Ensure that a stand-by person acts as a sentry;

1. Provide adequate Supervision, especially where contractors are involved; and

1. Prevent unauthorized entry.

For a useful toolbox presentation on the management of confined space entry work, click the link to our “process safety tools”.