Although the idea of this article originated from a PSSR debacle on a new process construction project, the information will apply to ALL building construction and so I have put this in the OSHA Compliance Category rather than the Chemical Process Safety category. Late last year we were finishing up a longterm project with a client who was building a new process that would eventually be a PSM/RMP covered process. SAFTENG was hired to perform an engineering review of the plans and aid in managing changes to the plans.
In the early stages of the design, it was decided that the process would be “open-air” (e.g. no walls or roof), but as the Minnesota winter set in (and it was even a mild winter in MN standards), it was decided to enclose the process so that construction work could continue and it would be more pleasant for workers in the winter months. However, this “change” is significant as we now needed ventilation, our electrical classifications/HAZLOCs will change, as will our fire ratings and egress doors. Of course, the client chose not to do a Management of Change for these changes because the process was not yet a PSM/RMP covered process (see my eyes roll). And the information I provided on the ventilation requirements, HAZLOCs concerns, and fire ratings never made it to the General Contractor.
We showed up for the Pre-Start Up Safety Review (PSSR) in February and their pile of mistakes came crumbling down. The GC was aware of the IBC requirements, but since it was not in the original scope nor budget and the client did not provide the required information, the GC was able to play dumb and say “we did what you asked”. Here is where they made their first mistake:
OSHA (MN-OSHA) has some minimum fire rating for exit doors leading to egress pathways (interior and exterior stairways)… (emphasis by me)
1910.36(a)(2) An exit must be separated by fire resistant materials. Construction materials used to separate an exit from other parts of the workplace must have a ONE-HOUR fire resistance-rating if the exit connects three or fewer stories and a TWO-HOUR fire resistance-rating if the exit connects four or more stories.
Remember this is an OSHA requirement and OSHA does not participate in a PSSR or issue occupancy certificates, but these are the bare minimum requirements.
This process had their egress stairs on the OUTSIDE of the building (more on this issue later!). When they enclosed the process structure they used metal siding and framed up the doors and windows with metal. But the process building/structure was 5 stories in height, meaning that the fire door(s) and all their assemblies must have a rating of 2-hours. The doors used were, in fact, UL rated fire doors but with a rating of 20 minutes!!! You can imagine there may be a price difference between a 20-minute fire-rated door and a 2/3 hour rated door and there were ten (10) doors.
So they got the right doors and installed them. But then we asked for the fire-rating of the blank-wall(s) that separated the stairs from the building they had nothing. Now does it make sense to spend the $ on 2-hour rated door(s), but then have a wall that carries no fire-rating that shields you as you go down the stairs? The idea is that when I exit the 5th floor and proceed down the stairs, I am shielded from the fire inside the building as I make my way down the stairs.
Mistake #2
One can imagine that in the state of MN they get some snow from time to time during the winter months. And because of this snowfall AND the fact they chose to use exterior stairs as their means of egress, then they will have to comply with… (emphasis by me)
1910.36(h) An outdoor exit route is permitted.
1910.36(h)(1) The outdoor exit route must have guardrails to protect unenclosed sides if a fall hazard exists;
1910.36(h)(2) The outdoor exit route MUST BE COVERED if snow or ice is likely to accumulate along the route, unless the employer can demonstrate that any snow or ice accumulation will be removed before it presents a slipping hazard;
1910.36(h)(3) The outdoor exit route must be reasonably straight and have smooth, solid, substantially level walkways; and
1910.36(h)(4) The outdoor exit route must not have a dead-end that is longer than 20 feet (6.2 m).
I always think about this picture when I think about an “outdoor exit” and the client telling me they will keep it clean…
In this case, the AHJ where this plant is located required the business to do three (3) things before she would issue an occupancy certificate:
1) insulate and double wall the blank walls to provide fire separation for the egress stairs
2) provide a cover over the egress stairs.
3) provide emergency egress lighting on all floors
Amazingly she had no issues with enclosing a chemical process and not providing ventilation for a HAZLOC. She required normal building ventilation for the permit to be issued.