Working in a confined space can be hazardous but working in a permit-required confined space (permit space) is often downright dangerous. That’s why it’s important that employers ask the question: Is the work done in the permit space considered a maintenance or construction activity? The answer to that question will determine if OSHA’s 29 CFR 1910.146 general industry standard or the 1926 Subpart AA standard must be followed.
There are several OSHA Letters of Interpretation (LOI) that will help an employer answer the maintenance or construction question.