By now you’ve probably heard about the about the Occupational Safety and Health Administration’s (OSHA) addition to 29 CFR 1926 Subpart AA that updates the rules for confined spaces in the construction industry. On May 4, 2015 OSHA announced the new rules which took effect on August 3, 2015. Since that time, the questions about atmospheric monitoring have been pouring in, but we’re here to help! Below are some of the most common questions we’ve received, followed by responses from our Director of Applications Engineering & Product Knowledge, Dave Wagner.
Q) Do the changes in 29 CFR 1926 Subpart AA only apply to construction or to general industry as well?
A) This standard only applies to operations that are considered as construction. The general industry standard remains the same.
Q) Is maintenance work completed in a confined space considered to be a part of the new confined space regulation?
A) No. Maintenance work falls under 1910.146.
Q) What is the basic difference between a “permit required” and “non-permit required” confined space?
A) A permit required confined space has the potential to contain a hazardous atmosphere or the potential for entrapment.
Q) Who owns liability if an incident occurs?
A) Under this standard, if it is a construction operation, the general contractor holds responsibility for the confined space entry.
Q) What does the term “potential” mean in the “potential to contain hazardous atmosphere” if the potential sources have been locked out, blocked out, and the space ventilated before the pre-testing occurs?
A) The potential existed before any of those measures were implemented, therefore the potential exists and it must be monitored for. Lock out, and blocking are only means of mitigating the hazard, not for eliminating its existence.
Q) Do entrants need to continuously monitor the atmosphere within the space?
A) The space must be continuously monitored. It does not need to be done by an entrant, but the entrant must be able to be notified if the atmosphere changes and a hazardous condition occurs. Therefore it makes sense for the entrant to have a monitor in the space.
Q) Can a minimum of two trained workers (entrant and attendant) legally perform a permit required confined space entry or must you have three people including a supervisor?
A) It is possible to perform an entry with just an attendant and entrant. The entry supervisor could be the attendant, but the entry supervisor does not necessarily need to be present. He just needs to sign the permit.
Q) Is lowering a gas detector that records peaks and lows acceptable if the space is dry?
A) Lowering a monitor is only acceptable to most manufacturers as a last resort. A remote sample pump should always be used and the proper sample should be taken to get accurate readings.
Q) So what is recommended to lower the gas detector down into a vertical tank if ropes or probes are not acceptable?
A) A sample pump with flexible tubing should always be used instead of lowering a monitor in the space.
Q) Do you monitor in layers for buoyancy?
A) Yes, the standard says that the atmosphere should be measured at four-foot intervals to allow for stratification of gases.
Q) If you introduce forced air ventilation into a confined space, do you need to do continuous monitoring?
A) Yes, the standard requires monitoring to ensure the effectiveness of the ventilation.
These answers only cover some of the questions raised by the new construction standard. When in doubt, seek guidance from a trained safety professional. If you still have questions specific to gas detection in confined spaces, download our white paper, “Confined Spaces in Construction and Atmospheric Testing.”