Reviewing Readiness Before Startup

On Thursday, 3 September 2026, a fire with a loud blast broke out at the PT Evyap Sabun Indonesia plant in the Sei Mangkei Special Economic Zone (KEK), Simalungun Regency, North Sumatra. Three contractor workers died after falling from the sixth floor while trying to escape (Sinaga, 2026). The palm-based oleochemical plant, built from 2023, officially started operating on 2 July 2026 according to the National Council for Special Economic Zones, with a capacity of 650,000 tonnes a year of fatty acids, glycerine, soap noodles and soap (Sinaga, 2026). The fire came about two months into operation.

Early operation is a known period of elevated risk. The US Chemical Safety Board, citing the Center for Chemical Process Safety, states that process safety incidents occur five times more often during startup than in normal operation, and that a 2010 refining study found 50 percent of them occur during startups, shutdowns and other infrequent events (U.S. Chemical Safety and Hazard Investigation Board [CSB], 2018). The tool for this period is the pre-startup safety review (PSSR), a formal check that a new or modified facility is ready before hazardous materials go in.

This article explains PSSR as a method: concept, steps, application and limits. Our frame is the operational readiness element of CCPS Risk Based Process Safety, the PSSR and management of change clauses of OSHA 29 CFR 1910.119, and Indonesian rules on design control and testing of OHS objects, with sources searched on 6 November 2026. The Sei Mangkei event is context, not a case whose cause we analyse.

Facts So Far

The Simalungun police estimated that the fire started at around 10.10 local time. Flames were first seen on the third or fourth floor with a loud bang, then spread to the fifth and sixth floors (Sinaga, 2026). The police chief said initial information from company security placed the fire in the beading plant, and that the identification team was working with the Medan forensic laboratory on the origin and cause, with no conclusion before the technical examination (Pribadi, 2026).

All three victims were third-party workers. The police described them as carrying out maintenance work (Pribadi, 2026), while Kompas reported that they were welders from the plant's construction vendor working on the sixth floor (Sinaga, 2026). The fire was brought under control in the afternoon, with 13 fire engines deployed (Sinaga, 2026).

The next day, the Ministry of Industry said it was coordinating with the zone operator, the company, police and regional agencies on a thorough evaluation, and urged industry to treat periodic safety audits, internal firefighting readiness and emergency procedures as a top priority (Sugara, 2026). At the time of writing we found no official investigation report or announced cause, so we do not speculate on the cause or judge any party.

Why Startup Is Risky

Both figures need care: the first comes from a 1995 CCPS guideline citing 1992 property loss data, the second from one refining study (CSB, 2018). Newer research points the same way.

Vaughen (2020) reviewed more than 50 incidents linked to transient operations and identified 10 startup and shutdown modes. Administrative and engineering controls had failed to work as planned, and an effective readiness review before restart could have reduced many of the risks (Vaughen, 2020). An HFACS analysis of 251 chemical accident reports found organisational process factors in 91.66 percent of accidents in the shutdown and startup group, more than in any other group (Yalçın et al., 2023). The abstract does not give the size of that group, so the figure needs caution.

Part of the problem originates in design. A review of equipment accident cases in the Failure Knowledge Database found design errors in 79 percent of cases, led by poor layout (17 percent) and insufficient consideration of chemical reactivity and incompatibility (16 percent) (Kidam & Hurme, 2012). Such errors surface when the unit runs unless someone looks for them before startup.

The best documented example is the residue treater explosion at Bayer CropScience in Institute, West Virginia, on 28 August 2008, which killed 2 people and injured 8 during a restart after the control system and vessel were replaced. The CSB's first cause was that standard PSSR and turnover practices were not applied, so equipment was not tested and calibrated; operators were also not adequately trained on the new distributed control system (DCS) (CSB, 2011).

How a PSSR Works

Four Required Confirmations

The US process safety management standard requires a PSSR for new facilities and for modifications that change the process safety information. Before highly hazardous chemicals are introduced, it must confirm that (1) construction and equipment match design specifications; (2) safety, operating, maintenance and emergency procedures are in place and adequate; (3) for new facilities, a process hazard analysis has been done and its recommendations resolved before startup, while modified facilities meet management of change requirements; and (4) every employee operating the process has completed training (Occupational Safety and Health Administration [OSHA], 2026). Its management of change clause requires affected employees and contractors to be trained before startup (OSHA, 2026).

CCPS places PSSR within the operational readiness element of Risk Based Process Safety, with wider scope: readiness is checked before startup from any shutdown condition (Center for Chemical Process Safety [CCPS], 2007b). CCPS has also published risk-based PSSR guidelines, so the depth of review matches the hazard (CCPS, 2007a), and later guidance on the transient operating mode (CCPS, 2021). A PSSR has two possible outputs: the unit is ready to start, or a list of actions to complete first.

Indonesian Reference Points

The term PSSR does not appear in the Indonesian regulations we reviewed, but parts of it do. Annex II of Government Regulation No. 50 of 2012 on the Implementation of Occupational Safety and Health Management Systems contains criterion 3.1.1 on risk control in design and modification, criterion 3.1.3 requiring a competent person to verify that a design or modification meets OHS requirements before the design is put to use, and criterion 3.1.4 requiring every design change with OHS implications to be reviewed and approved by an authorised person before implementation (Pemerintah Republik Indonesia, 2012). Criterion 3.1.1 applies at the initial level, while 3.1.3 and 3.1.4 are only assessed at the transitional level. Criterion 6.1.5 on a permit to work system for high-risk tasks applies from the initial level (Pemerintah Republik Indonesia, 2012).

For equipment, Minister of Manpower Regulation No. 37 of 2016 on pressure vessels and storage tanks requires a first inspection and/or test at design, fabrication, before use, and on installation or modification (Article 71), covering among other things drawings, material certificates, non-destructive testing and a hydrostatic test (Article 73) (Kementerian Ketenagakerjaan [Kemnaker], 2016). Minister of Manpower Regulation No. 11 of 2026 on labour inspection procedures defines the first test as testing a new OHS object before operation (Article 40), requires a special test after serious damage or a process change (Article 42(2)), and lets a compliance certificate lapse after an accident, serious damage or a change to the object (Article 45(8)) (Kemnaker, 2026).

The Method in Practice

A PSSR report from a 400,000 tonne a year HDPE plant in Malaysia shows the scale of the work. The review began in the second quarter of 2019 at 80 percent mechanical completion, was run twice by multidisciplinary teams (licensor with contractor, then owner with contractor) in three sessions following the startup sequence, and combined document review with site walks covering escape routes and fire protection and detection (Di Vito, 2020).

The reviews produced 832 recommendations. Severity 3 to 5 items (PS1) had to be closed before startup; severity 1 and 2 items (PS2) could be closed afterwards. From the tables in the paper we count 645 PS1 items (about 78 percent) and 187 PS2 items. The ready-for-startup certificate came only after every PS1 item was closed with evidence, and hydrocarbons were introduced on 31 December 2019 without incident or equipment damage (Di Vito, 2020). It is one contractor-reported project, yet it shows a well-run project can reach startup with hundreds of gaps.

Another study built a PSSR tool of 227 questions across 10 disciplines, from operations and process safety to an action log, a final walk-down and approval, with a content validity index of 0.98 from expert rating (Abu Bakar & Abdul Aziz, 2024). Its validation has not yet been measured against incident reduction.

The Bayer case shows the other side. Its eight-page PSSR checklist marked items complete when they were not: adequate procedures were answered "yes" although procedures had not been revised, a missing valve and a broken valve went undetected, and incomplete items had no due dates. The review was not multidisciplinary, the toxic gas monitoring system was out of service, and critical DCS control circuits had not been verified (CSB, 2011).

Reading the Transition

On this evidence, we see commissioning and the first months of operation as a distinct high-risk phase. A new design meets the real process for the first time, operators do not yet know the unit, procedures are untested and the punch list is open. The evidence is limited and partly old, but consistent.

The Sei Mangkei event illustrates an easily overlooked feature of this phase: contractor work in the same building as a running unit. Reports confirm only that contractor workers were on the sixth floor when the fire appeared lower down (Sinaga, 2026; Pribadi, 2026), and that fact does not indicate a cause. In an operational readiness frame, investigators would normally ask whether the unit had passed a PSSR and handover, which items were open, how contractor work was separated from the live process through permits and isolation, whether contractors knew the fire and explosion hazards of their area, and what escape routes existed from the upper floors. This list comes from the method, not from investigators.

Indonesian regulation leaves a gap. First tests and OHS certificates examine one object at a time; a PSSR examines the system: procedures, training, HAZOP close-out, safety instrumentation and emergency response. A plant can hold a certificate for every vessel and still not be ready to start. Criteria 3.1.3 and 3.1.4 of Government Regulation 50/2012 come closest, but they are general and assessed only at the transitional level. In the regulations we reviewed, we found no obligation to carry out a PSSR as a system review for chemical and oleochemical plants.

The method has limits. A PSSR is a snapshot; a complete checklist is worthless if answers are not verified in the field (CSB, 2011), and an expert-validated tool has not yet been shown to reduce incidents (Abu Bakar & Abdul Aziz, 2024). Its quality depends on team independence, the evidence demanded and a willingness to delay startup.

A PSSR That Works

We drew the following steps from the requirements and evidence above:

• Define triggers in writing: new units, modifications under management of change, and restarts after long or unplanned shutdowns (OSHA, 2026; CCPS, 2007b).
• Form a multidisciplinary team (operations, process, instrumentation, asset integrity and safety) led by someone outside project delivery; a review without operators was a weakness the CSB (2011) recorded.
• Start before 100 percent mechanical completion and split the review by startup sequence so findings can still be closed (Di Vito, 2020).
• Verify in the field: valves, instruments, interlock and gas and fire detection function tests, relief valves, escape routes and firefighting equipment.
• Rank findings by severity, decide which must be closed before startup, and give every item an owner and a due date (Di Vito, 2020; CSB, 2011).
• Confirm that HAZOP recommendations are closed, procedures revised, and operator training on any new control system recorded (OSHA, 2026).
• While part of the plant runs and part is still being built, set area boundaries, issue hot work permits, brief contractors on fire and explosion hazards, and include them in emergency drills (OSHA, 2026; Pemerintah Republik Indonesia, 2012).
• Align with first tests, special tests after changes and valid OHS certificates (Kemnaker, 2016, 2026).

The PSSR team recommends; startup approval is best signed by the owner's manager responsible for operations, since OSHA places the PSSR duty on the employer (OSHA, 2026) and in the HDPE example the licensor and owner confirmed closure (Di Vito, 2020). Keep the evidence: checklists with photos and test records, the findings register, management of change records, current P&IDs, revised procedures, training records, test reports, OHS certificates and the signed approval.

How Nusa Safety Helps

Nusa Safety can help prepare new or modified units before they start. Through a process safety management review, the Nusa Safety team examines operational readiness, management of change and follow-up of findings against conditions in the field. Outdated hazard analyses can be refreshed through HAZOP and LOPA studies, and startup, shutdown and PSSR procedures written through SOP and technical guideline development.

For first tests of pressure vessels and other OHS objects, Nusa Safety coordinates statutory equipment inspection with licensed PJK3 partners; Nusa Safety is not a PJK3 and does not issue OHS certificates. Emergency preparedness drills can be held before startup so employees and contractors know the escape routes; for these programmes Nusa Safety issues internal training certificates only. The Nusa Safety team can be reached through the contact page.

This article is general information and not legal or professional advice for any specific case.

References

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