[Haichuan Accident Case] Fire accident on the project to install oxygen liquefaction equipment in the under-construction hot rolling area of Tianjin Iron Plant, 20180510

Course of the accident and rescue efforts: On May 10, Zhou X, Zhang Xmin, and Chen X, workers organized by Wang X from XX Construction Group, went to the middle of the roof of the secondary span in the main building of the oxygen production plant to carry out tasks of grinding grooves and welding DN600 nitrogen pipes； At around 10:20, the pressures of the oxygen turbo compressors No. 5 and No. 6 at the oxygen production station exceeded the set values; as a result, the relief valves opened and oxygen was released. Zhou X, who was working on grinding tasks, had his clothes catch fire and they began to burn rapidly. Zhang Xmin immediately stepped forward to try to put out the fire by slapping at it, but was burned in the process. Chen X used a fire extinguisher to put out the flames on Zhou X’s body. Subsequently, Zhang Xmin ran downstairs to call for help, and the relevant personnel dialed the 120 emergency number; an ambulance took Zhou X and Zhang Wanx to the hospital for treatment.

Causes and nature of the accident: (1) Direct cause – Through expert analysis and investigations, the accident investigation team determined that the direct cause of this accident was intense combustion that occurred in a locally oxygen-rich environment created by the high-concentration oxygen emitted from oxygen release port No. 6, as a result of the sparks generated by the construction workers’ grinding operations. (II) Indirect causes: 1. Su Hua Company did not assign full-time safety officers to be responsible for safety management at the construction site, nor did it implement appropriate safety measures at the site in accordance with the construction conditions ； The oxygen-rich environment that could arise at the construction site was not identified prior to work commencement, and the fire safety risks associated with workers carrying out grinding tasks in such an environment were not addressed in a timely manner ； The technical requirements for safe construction were not explained in detail to the workers, and adequate fire safety training was not provided to them ； The workers carried out pipe grinding tasks without confirming the safety measures for hot work, without providing safety instructions to the workers performing the hot work, and without having a supervisor present at the site. 2. The project construction plan prepared by Sichuan Air Branch is highly inconsistent with the actual conditions; it shows signs of being copied verbatim. The plan fails to conduct a comprehensive identification of the dangerous and harmful factors at the construction site, nor does it specify concrete fire safety measures, and the safety measures outlined in the plan are not properly implemented ； The behavior of construction workers carrying out work without having obtained the necessary firework operation permits was not detected and stopped in a timely manner ； The on-site safety inspections were inadequate, failing to promptly eliminate the fire safety risks associated with workers carrying out grinding tasks in an environment that could be oxygen-rich ； There was inadequate unified coordination and management of the safety production efforts of Su Hua Company, the subcontractor responsible for the installation and construction of the oxygen liquefaction project; issues related to safety management at the construction site, safety technical instructions, and training and education on the part of Su Hua Company were not identified and corrected in a timely manner. 3. The new company failed to thoroughly review the project construction plan prepared by Sichuan Air Branch; it did not point out issues such as the severe discrepancies between the plan and the actual conditions on site, as well as the fact that the plan was copied verbatim. It also failed to propose any revisions or effective protective measures regarding the lack of specific fire safety measures outlined in the plan ； There is insufficient awareness of the dangers associated with the oxygen-rich environment that results from the release of oxygen by oxygen release devices; the instruction to evacuate promptly upon the activation of the alarm systems mentioned in the safety briefings is not a truly effective safety measure ； The fire safety risks associated with construction workers carrying out tasks such as grinding in an environment where oxygen levels may be high were not identified in a timely manner, nor were effective measures taken to eliminate these risks ； There was inadequate unified coordination and management of the safety production efforts by Sichuan Air Separation Company, the contractor responsible for the installation and construction of the oxygen liquefaction project; various issues that arose during on-site construction by this company were not identified and corrected in a timely manner. 4. At the Tianjin Iron Plant, the approval process for construction plans was a mere formality; it failed to point out issues such as the serious discrepancies between the construction plans and the actual conditions on site, as well as the copying of existing plans without any modification. No suggestions were made to address issues in the construction plans regarding the lack of specific fire safety measures, nor were any effective protective measures proposed ； The behavior of construction workers carrying out work without obtaining the necessary firework operation permit was not detected and stopped in a timely manner ； There is inadequate unified coordination and management of safety production for the outsourced oxygen liquefaction project.

On September 15, 2017, the bid evaluation committee recommended that the project to install oxygen liquefaction equipment in Tiantie Group’s hot rolling section be awarded to Xinnrui Company. On September 25, 2017, a turnkey EPC contract for the design, procurement, and construction of the oxygen liquefaction project was signed with XX Company in the name of Tianjin Iron Plant. What is the relationship between Tiantie Group and Tianjin Iron Plant? Does Tianjin Iron Plant have the qualifications to act as the employer? . . . Outsourcing to Xinrui Company. . . Another EPC turnkey contract was signed with XX Company; what is the relationship between this newcomer and XX? Do they, individually or as a group, possess general contracting qualifications? On March 7, 2018, XX Company subcontracted the professional work of installing and commissioning the oxygen liquefaction units as well as related supporting equipment in the hot rolling section of Tiantie Group to XX Air Branch. On March 19, 2018, XX Air Separation Cryogenic Engineering Installation Co., Ltd. subcontracted the installation and commissioning project of an oxygen liquefaction unit and related supporting equipment in Tiantie Group’s hot rolling area to XX Construction Group Co., Ltd. With new companies like XX Company, the XX Air Branch, and XX Construction Group, and through successive subcontracting, safety and quality are compromised, which leads to the consequences that followed

××Who conducted the risk analysis for the manual work signatures in the construction group, and how was it done? Have the parties entrusted with the work (ranging from the constructor to various levels of subcontractors) been informed about the conditions on site (such as the presence of high-purity oxygen)? Did the personnel of the construction group take the necessary control measures before carrying out the work?

Three questions for Tiantie Company? 1. What role does Xinrui Company play in this project? Who is Su Hua Company? Without sufficient information (which is the responsibility of the constructor and the higher-level client), construction companies are unable to identify potential oxygen-rich environment hazards and take measures to prevent them. 2. Who is the EPC contractor, Company XX? Does it have the general contracting qualifications? How was the EPC general contract between you two signed? 3. Why does subcontracting occur at multiple levels? By the way, you shouldn’t approve the construction plan (if you did approve it). You can indeed participate in the joint review to check whether the boundary conditions provided by you as the constructor have been properly considered and adopted, such as the direct cause of the accident: high-purity oxygen.

It is also because of this special environment that this case is being shared == for example, the direct cause of the accident was high-purity oxygen. The construction team might really not be aware of this environment