A pre-startup safety review (PSSR) is a critical element of the process safety management (PSM) program mandated by the United States Occupational Safety and Health Administration (OSHA). However, due to time constraint and budget pressures, the temptation to rush or completely neglect the PSSR often exists.
OSHA implemented the PSM program in 1992. It spelled out the need for a PSSR in 29 CFR (Code of Federal Regulations) 1910.119(i):
1910.119(i)(1) — The employer shall perform a pre-startup safety review for new facilities and for modified facilities when the modification is significant enough to require a change in the process safety information.
1910.119(i)(2) — The pre-startup safety review shall confirm that prior to the introduction of highly hazardous chemicals to a process:
1910.119(i)(2)(i) — Construction and equipment is in accordance with design specifications;
1910.119(i)(2)(ii) — Safety, operating, maintenance, and emergency procedures are in place and are adequate;
1910.119(i)(2)(iii) — For new facilities, a process hazard analysis [PHA] has been performed and recommendations have been resolved or implemented before startup; and modified facilities meet the requirements contained in management of change, paragraph (l).
1910.119(i)(2)(iv) — Training of each employee involved in operating a process has been completed.
The PSSR frequently is the last line of defense before bringing an updated or new process online to ensure:
• It has been designed properly.
• The equipment and process information is complete and available.
• The equipment is installed per the design specifications.
• A PHA has been conducted and associated, documented recommendations have been addressed.
• Documented safety, operating, maintenance and emergency procedures are adequate and complete.
• All training of operations personnel has been finished.
One item not specifically spelled out in this regulation but probably included in the intent for equipment is the safety instrumented system (SIS) with associated distributed control system (DCS), programmable logic controllers (PLC) and stand-alone digital or analog controllers and alarm systems. It provides alarms to alert operators if the process is starting to get out of control and interlocks to take certain actions, intervene or even stop the process, if necessary. Ensuring the automated valves, associated process instrumentation, alarms and interlocks are active and functioning as designed can require significant time and effort before starting a new or updated process or restarting a process after a major shutdown.
Incidents Underscore Importance
In March 2005, the BP Texas City refinery suffered a major disaster that killed 15 and injured more than 170 others. (For details, see the report issued by the U.S. Chemical Safety Board (CSB).) BP hadn’t properly conducted safety critical checks. The CSB investigators found an inoperative pressure control valve, a defective high-level alarm and an uncalibrated sight-glass level transmitter as well as portable trailers with non-essential personnel located too close to the process.
In incidents at two other sites, improperly conducted PSSRs of process control and system settings led to equipment and process damage with financial and business impact. Fortunately, neither caused deaths or injuries.
In the first event, equipment manufactured in Europe and shipped to the United States had a 50-Hz motor setting remaining from preliminary testing overseas. That setting should have been changed to 60 Hz for U.S. operations. Failure to alter the setting caused the motor to run slower and resulted in a process shutdown due to high temperature. Operational steps taken while cooling the process led to a propagating fireball explosion that caused extensive damage to the outdoor process equipment and some siding on the building.
In the other incident, a manufacturing operation replaced a circuit board, treating this as an in-kind change, although the board actually was an updated version. The site didn’t conduct a PSSR and, thus, didn’t uncover that several critical interlocks weren’t operational due to the board replacement. The result was a damaged shaft, plus repair and replacement cost, and the associated lost production time (8–10 weeks).
Properly performed PSSRs would have prevented these three events. Ensuring a thorough PSSR requires both qualified employees and knowledgeable, safety-minded management. The PSSR also should get reviewed and approved before allowing processes to be brought online or restarted.
Effectively conducted PSSRs can prevent incidents and the resultant harm to personnel, equipment damage, and loss of production and profits. According to OSHA, the ultimate responsibility lies with plant or facility management to ensure a PSSR is properly conducted before a covered process is started.
Unfortunately, some common errors often undermine efforts:
• failure to conduct a PSSR after process modifications or a prolonged equipment outage;
• assembling a team without the necessary knowledge and skills to adequately perform the PSSR;
• skipping or forgetting parts of the PSSR needed to ensure the process is completed and ready to start;
• omitting critical safety features from the review or not checking them for proper installation and operation; and
• lack of appropriate approval steps for the PSSR before proceeding to start or restart the process.
Following good practices can help ensure a PSSR is performed properly. Five key ones are:
1. Assign a leader to be in charge of the PSSR team. This person should have sufficient authority to delay the startup if the team identifies a significant deficiency. Given that such a delay could lead to a serious financial loss, very strong pressure to allow a deficient process to start up may arise. So, the leader must have the personality, skills, knowledge, determination and organizational authority to resist such pressure.
2. The leader should assemble an appropriate multi-disciplined team of personnel (design and construction, engineering, instrument and controls, maintenance, operations, safety and supervisors) to complete the PSSR and the additional follow-up activities.
3. The team should use a checklist or other suitable PSSR form to verify all required parts of the PSSR are completed.
4. Ensure the team understands all the process equipment subject to the PSSR. This should include tanks, vessels, reactors, mixers, connecting piping, etc., as appropriate, as well as the associated instrumentation and controls, including the DCS or PLC.
5. If necessary, consider using third-party contractors and consultants to supply necessary information or technical expertise on the equipment or process under review.
A Critical Step
A PSSR may resemble a hazard analysis, although it’s not aimed solely at identifying new hazards. Rather, the PSSR is intended to ensure the plant or process about to be started is safe and operable.
Don’t treat a PSSR as just an exercise in filling out a form or ticking boxes on a checklist. Sometimes, it’s necessary to perform nondestructive or other appropriate tests on the equipment, instrumentation and control systems in the field before starting a process. You must do whatever is required to have high confidence the equipment and associated instrumentation and control systems function properly as designed and intended, and critical safety devices can’t be bypassed.
A PSSR mainly serves for verification, not the identification of new hazards. It provides the last opportunity for the team associated with a project to ensure the possibility of an unsafe condition doesn’t exist before the process goes into operation and potentially hazardous chemicals are introduced. In addition, it enables the team responsible for the design, operation and maintenance of the process, including facility management, to check — before starting up — that effective procedures have been written and the operators and maintenance personnel have been trained on the process.
