Know the basics of air monitoring for construction permit-space entry
Permit-required confined spaces can be very dangerous places. That’s why OSHA has regulations that say all employees entering a permit-required confined space must be instructed as to the nature of the hazards involved. Atmospheric testing is required to evaluate the air in the confined space, verify that conditions for entry are acceptable, and continuously monitored to ensure conditions remain acceptable.
OSHA’s rule at 29 CFR 1926 Subpart AA says that appropriate atmospheric tests must be made to either determine if the permit space meets the requirements for the alternate procedures, or to determine whether atmospheric hazards have been eliminated or controlled.
There are specific guidelines for monitoring permit spaces. Use these guidelines to evaluate permit space conditions: (1) before entry is authorized, and (2) as necessary to ensure they are acceptable during work. If the space is too large to isolate, testing should be done to the extent feasible before entry, and continuously where (and when) entrants are working.
The rule also says you should: (1) test for oxygen first because most combustible gas meters are oxygen dependent and will not provide reliable readings in oxygen deficient atmospheres; then (2) test for flammable gases and vapors because the threat of fire or explosion is both more immediate and life threatening (in most cases), and (3) then test for toxic air contaminants.
In addition, OSHA requires that the: (1) person in charge must know the proper use and calibration of monitoring equipment and supervise its use, (2) authorized entrants must know how to use the testing and monitoring equipment. Employees entering the space must be allowed to observe the initial monitoring of the space.
Training is required per 1926.1207, which says employers provide training so that all employees acquire the understanding, knowledge, and skills necessary for the safe performance of the duties assigned.
Finally, training must also establish employee proficiency in the duties required and introduce new or revised procedures, as necessary, for employee safety. Certification of the training is required to ensure that it has taken place, and that certification must be available for inspection by employees and their authorized representatives.
