On the morning of Sunday 12 October 2025, a scrubber tower at a nickel processing facility in the Indonesia Morowali Industrial Park, Central Sulawesi, caught fire. According to the park's management, the fire broke out at about 08.30 and was extinguished at 09.10, three workers suffered minor injuries, and no one died (Putri, 2025). Two days later, the Minister of Energy and Mineral Resources asked the Directorate General of Minerals and Coal to send a team to the site (Warta Ekonomi, 2025).
Fires during maintenance or construction work like this raise the same questions at many plants. We have gathered the six that come up most often on site and answered them from traceable sources.
What Is Known?
Only early accounts are available. The park's management said the provisional view was that sparks from welding at height fell onto part of a tank made of fibreglass (Putri, 2025). Early investigation findings quoted in the media on 14 October referred to welding on a stack and sparks landing on a tarpaulin that covered a fibreglass tank below (Warta Ekonomi, 2025). At the time of writing, no official investigation report is available. What follows therefore discusses mechanisms that are commonly examined in hot work fires, as a direction for learning and not as the cause of this event.
Why Scrubbers Can Burn
The early accounts mention a fibreglass tank, that is, fibre-reinforced plastic (FRP), a material also used for scrubbers and tanks at many plants. Polymer composites of this kind can burn and release heat, smoke and toxic gases, and their fire behaviour depends on the resin and fibres they are made of (Mouritz & Gibson, 2006). Equipment that holds no flammable material on paper can therefore become fuel once an ignition source arrives. Which material burned first in Morowali is for the investigation to establish.
How Far Sparks Travel
The OSHA standard for welding and cutting requires a fire watch where appreciable combustible material lies within 35 feet, or 10.7 metres, of the work, or further away but easily ignited by sparks. Where practicable, combustibles are to be moved at least 10.7 metres away; where they cannot be moved, they are to be protected with flameproofed covers or metal guards. The fire watch stays for at least half an hour after welding ends to catch smouldering fires (Occupational Safety and Health Administration [OSHA], 2024). In our view two points stand out: an ordinary tarpaulin is not a fire-resistant cover, and the 10.7-metre zone also runs downward when the work is done at height.
Lessons From Elsewhere
The US Chemical Safety Board (CSB) reviewed 11 hot work accidents in, on or near tanks and drew seven lessons: use alternatives to hot work, analyse the hazards first, monitor the atmosphere with a gas detector, test the surrounding area, use written permits, train workers, and supervise contractors. In 7 of the 11 accidents there was no gas testing before or during the work (U.S. Chemical Safety and Hazard Investigation Board [CSB], 2010). The CSB cases involved flammable vapours, unlike the early account from Morowali, but the pattern is similar: hazards around the work point were not recognised before the flame was lit.
Who Is Responsible?
This question often comes first, and in our view it is not the most useful one. Hot work involves a permit issuer, the person doing the work, a fire watch and the area owner, so failures usually grow from gaps between roles rather than from one person. The CSB treats written permits issued by people who know the site hazards, and the supervision of contractors, as lessons in their own right (CSB, 2010). The more productive question is which role did not work, and that answer is what the official investigation should provide.
What Should Plants Do?
- List the FRP and plastic equipment on site, including scrubbers, cooling towers and tanks, and mark it on the permit area plan.
- Extend hot work permit checks to the space below the work point, not just around it.
- Replace ordinary tarpaulins with fire-resistant blankets or covers.
- Assign a fire watch with an extinguisher during the work and for at least half an hour afterwards.
- Test the atmosphere with a calibrated gas detector wherever flammable vapour may be present.
Hot work is often treated as routine because it happens almost daily, especially during construction and maintenance. Precisely because it is routine, a permit can turn into a form that is signed without a site check. A joint check at the work point by the permit issuer and the worker, including a look downward, is a simple habit that closes that gap.
Nusa Safety helps companies assess fire protection readiness through its Fire and Emergency Safety Audit (FESA), build job hazard analyses in its Risk Assessment and JSA Workshop, and train teams to trace incident root causes through Incident Investigation and RCA.
This article is general information and not legal or professional advice for any specific case.
References
- Mouritz, A. P., & Gibson, A. G. (2006). Fire properties of polymer composite materials. Springer. https://doi.org/10.1007/978-1-4020-5356-6
- Occupational Safety and Health Administration. (2024). General requirements: Welding, cutting, and brazing (29 CFR 1910.252). https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.252
- Putri, R. N. F. (2025, October 12). Menara scrubber di kawasan IMIP Morowali terbakar, tiga karyawan terluka [Scrubber tower in the IMIP Morowali area catches fire, three employees injured]. JawaPos.com. https://www.jawapos.com/berita-daerah/2510120302/menara-scrubber-di-kawasan-imip-morowali-terbakar-tiga-karyawan-terluka
- U.S. Chemical Safety and Hazard Investigation Board. (2010). Seven key lessons to prevent worker deaths during hot work in and around tanks (Safety Bulletin No. 2009-01-SB). https://www.csb.gov/assets/1/20/csb_hot_work_safety_bulletin_embargoed_until_10_a_m__3_4_10.pdf
- Warta Ekonomi. (2025, October 14). ESDM kirim tim investigasi ke IMIP usai kebakaran fasilitas pabrik nikel [Energy ministry sends investigation team to IMIP after nickel plant fire]. https://wartaekonomi.co.id/read586275/esdm-kirim-tim-investigasi-ke-imip-usai-kebakaran-fasilitas-pabrik-nikel
