Document ID: chunk:federal_register_of_legislation:F2016L00405:body:0:p13
Version: federal_register_of_legislation:F2016L00405
Segment Type: other
Provision Reference: 
Character Range: 32611–35509

in adjacent areas
          + prohibiting smoking and naked flames within the confined space and adjacent areas
          + avoiding contamination of breathing air from operations or sources outside the confined space, for example, from the exhaust of an internal combustion engine
          + prohibiting movement of equipment in adjacent areas, for example forklifts
          + prohibiting spark-generating equipment, clothing and footwear
    * whether purging or cleaning in the confined space is necessary
    * whether hot work is necessary
    * conditions that could impede entry and exit or the conduct of the tasks in the confined space, for example, plant layout, dimensions, manual handling and ergonomic aspects of the task activity.

Atmospheric testing and monitoring
Testing and monitoring the atmosphere in a confined space is a routine part of determining appropriate control measures.

Regulation 50: A person conducting a business or undertaking must ensure that air monitoring is carried out to determine the airborne concentration of a substance or mixture to which an exposure standard applies if:
  -         there is uncertainty whether or not the airborne concentration of the substance or mixture exceeds the relevant exposure standard, or
  -         monitoring is necessary to determine whether there is a risk to health.
Any air monitoring in a confined space should be carried out by a competent person using
a suitable, correctly calibrated gas detector. It may be necessary to test the atmosphere for:
    * oxygen content
    * airborne concentration of flammable contaminants
    * airborne concentration of potentially harmful contaminants (for example, hydrogen sulphide and carbon monoxide ).
A person's senses should never be used to determine if the air in a confined space is safe. Many toxic or flammable gases and unsafe oxygen levels cannot be detected using one's senses.
Initial testing should be done from outside the confined space by inserting a sample probe and/or portable gas detection device at appropriately selected access holes, nozzles and openings. Because contaminants can settle at different levels, each part of the confined space should be tested – side to side and top to bottom (see Figure 2).
For example, some gases (such as hydrogen sulfide) are heavier than air and in unventilated areas will settle to the bottom of the space, while other gases (such as methane) are lighter than air and will collect at the top of the space. Testing should be carried out on a sufficient number of points to accurately reflect areas of the space that is likely to be accessed.

Figure 2 Atmospheric testing of remote regions and different levels within the confined space.

Lighter gases may be vented into the breathing zone of the person conducting the tests. Some gases may be dissolved in liquids and released when the liquid is disturbed