The most in-depth and practical analysis to date of the “3·21” explosion accident in Xiangshui (4)

This is the third installment, the Corporate Edition.

This article was published ahead of schedule; it’s a bit lengthy, so you’ll need to read it patiently.

Much has already been said about the importance of safety. Safe operations are a core competitive advantage for chemical companies, and those that fail to prioritize safety today will undoubtedly struggle to achieve long-term success.

This article, centered on the topic of preventing catastrophic accidents, offers practical guidance to chemical‑industry enterprises seeking to enhance their safety performance.

Over the past years, the progress made by domestic chemical enterprises in safety has been widely recognized; however, a significant number of companies still operate under relatively high risk levels—many function at a risk profile where a single fatal accident might occur once every 1 to 100 years, when assessed in terms of the risk associated with an individual accident scenario. Such risk levels remain unacceptably high. The elevated risk profiles of individual firms ultimately translate into a broader industry‑wide macro‑risk landscape; consequently, from a sector‑wide perspective, the occurrence of several major accidents each year is virtually inevitable.

How can enterprises ensure safety and prevent catastrophic accidents? The industry is abuzz with debate, and opinions vary: some advocate starting with the development of a safety culture, while others emphasize establishing a robust safety management system. In my view, for many domestic chemical companies, the immediate priority is neither the adoption of a safety culture nor the painstaking construction of a management system—though both are undoubtedly worthwhile. The pressing task is to promptly address existing shortcomings and put in place effective measures to prevent accidents.

What, then, constitutes an outstanding safety liability? On the one hand, many enterprises fail to conduct thorough, systematic hazard identification and implement adequate safety measures during the design phase of their process units. Based on my observations, only a small minority of HAZOP analyses meet acceptable standards; too often, they are little more than perfunctory exercises aimed solely at securing regulatory approval. Moreover, subsequent modifications—large or small—made after commissioning mean that, although the facilities are currently in operation, they are effectively “working with defects” and operating under elevated risk conditions. On the other hand, some plants have been in service for many years, resulting in significant equipment corrosion and aging, which heighten the risks of mechanical integrity failures and hazardous chemical leaks.

For most domestic chemical enterprises, it is advisable to implement accident-prevention measures on both short-term and long-term fronts. In the short term, this entails promptly addressing existing safety issues to prevent serious accidents; in the long term, it requires establishing a comprehensive safety-management system to ensure sustained, systematic progress in safety oversight.

In the short term, it is recommended to at least accomplish the following tasks:

1. Identify the major hazards that could lead to severe accidents as early as possible and implement appropriate safety measures. For example, for process units with high hazard potential, conduct a thorough HAZOP analysis or employ other comparable hazard‑identification methods, ensuring that all significant hazards are identified—specifically those that could result in hazardous chemical releases, fires, or explosions—and then develop a detailed action plan to promptly address the corrective measures recommended by the hazard analysis, assigning specific deadlines and individual accountability. Key personnel responsible for process technology, production, and maintenance—those who have an intimate understanding of the process—should actively participate in this effort* [Note] to ensure it is carried out effectively and yields meaningful results. For large‑scale enterprises, where completing this task may require considerable time, prioritize critical areas: tank farms, tanker loading and unloading, reaction processes, separation operations, process units involving flammable liquids under elevated temperature and pressure, high‑low pressure interfaces (to prevent high‑pressure from back‑flooding into low‑pressure systems), combustible dust handling systems, chemical storage facilities, and wastewater tanks containing solvents. These areas should be addressed first, taking into account lessons learned from the two most recent incidents; moreover, the storage of hazardous solid waste should also be included in the scope of this work.

Note: In many small and medium-sized chemical enterprises in China, the management of workshops or process units typically consists of three key roles: the workshop director (responsible for process operations), the equipment director, and the safety director. These individuals are constantly juggling both internal and external responsibilities, which significantly complicates the implementation of this task. Enterprises must devise strategies to address this challenge, including appropriately increasing staffing levels.

2. Building on the work outlined in Clause 1, review and update relevant operating procedures, and provide targeted training to frontline operators, with particular emphasis on identifying the primary hazards within the process system, the corresponding control measures, and the requirements for emergency operations.

3. Identify the particularly critical equipment in the process system—equipment or vessels whose failure could result in a severe release of hazardous chemicals—which typically accounts for approximately 15% to 20% of the total number of devices in the process system. Inspect their current condition (on-site inspection) and review the most recent inspection and testing records; if any items are found to be non‑compliant, repair or replace them promptly. During repair or replacement, implement appropriate safety measures to prevent accidents during the work.

4. If process units involving combustible dust are present, the risk of a dust explosion must be assessed. If it is difficult to implement complex corrective measures in the short term, at least basic safety measures should be put in place first, such as ensuring that static‑electricity grounding is intact; removing stored dust from the work area (avoiding large quantities of dust being kept on site); and conducting timely cleaning (with dust deposits on floors and equipment not exceeding 0.8 mm in thickness, while minimizing dust generation during cleaning); furthermore, equipment with a high risk of dust explosions—such as dust collectors and granulators—should be fitted with flame arrestors and explosion‑relief panels that vent to a safe outdoor location.

5. Manage the risks associated with high‑hazard operations, particularly the permitting and execution of hot work, pipe‑opening work, confined‑space entry, and work at height. The first two are closely linked to process safety, while the latter two pertain to operational safety and can readily result in fatal accidents. While hot work is generally given significant attention, few organizations have implemented a formal permit‑to‑open system for pipe‑opening activities—such as opening pipelines or vessels, for example, when replacing a valve on a process line. This area requires strengthening, as many injuries and fatalities occur during pipe‑opening operations.

Carrying out the aforementioned tasks is the bare minimum—its purpose is to provide temporary protection against serious accidents. Throughout the operation of a chemical plant, hazards that have not yet been eliminated are constantly racing against time; every moment counts!

The primary causes of accidents fall into two categories: management and technology. Management deficiencies often lie at the root of many catastrophic incidents, while technical shortcomings serve as the immediate triggers. In enterprises, we emphasize safety culture, management systems, and personnel training—these are all tools for achieving safety, but ultimately they must be grounded in the elimination of hazards and the control of risks. In the long term, a systematic safety management framework must be established to ensure that the plant consistently operates within acceptable risk levels.

Catastrophic accidents are entirely preventable! For well‑managed organizations, it is entirely feasible to go 100 years without a single catastrophic incident—provided that, during hazard analysis, the risk associated with each individual accident scenario is kept at no more than a once‑in‑10,000‑year occurrence. Conversely, if safety measures are not rigorously implemented and hazards remain unmitigated, the process system will operate under uncontrollable risk conditions, making an accident within a 100‑year period virtually inevitable—though the exact timing—whether in the first year, the fifth year, or the twenty‑fifth year—will still involve some element of randomness.

Systematic safety management has two key dimensions: first, it helps us eliminate or control major hazards as thoroughly as possible; second, it ensures that best practices are sustained and continuously refined. It operates on two levels: establishing and implementing formal management systems, and, within that framework, ensuring that competent personnel apply safety‑related technical measures. We will now explore these aspects in greater detail.

    1. Misalignment of safety responsibilities must be corrected.

In many enterprises, inadequate safety management stems from a fundamental misalignment of responsibilities: the prevailing view is that safety is solely the purview of the security department—often shared by top management. This misguided perception hinders the implementation of critical safety initiatives, ultimately thwarting organizations’ aspirations to achieve robust safety performance.

Enterprises must adhere to the principle that “production management entails safety management,” clearly assigning responsibility for safety to direct supervisors; only then can safety be effectively managed. For example, the project manager is ultimately responsible for safety throughout the project’s execution; the workshop supervisor is responsible for safety within that workshop; the process unit manager is responsible for the safety of the corresponding unit; the maintenance manager is responsible for the safety of the maintenance department—including external maintenance contractors; and the maintenance team leader is responsible for the safety of their respective maintenance team. It is not the enterprise’s safety department but these direct supervisors who bear genuine accountability for safety.

The primary responsibilities of an enterprise’s safety department are to develop the organization’s safety policies and procedures and to oversee their implementation—carried out by the personnel mentioned earlier. Of course, the safety department must also provide technical and regulatory support throughout the implementation process. While this last point is critical for the safety management function, in many small and medium-sized enterprises, safety departments are preoccupied with routine administrative tasks, leaving them little time for in-depth learning and professional development, thus preventing them from fulfilling their role as a specialized technical support unit. In larger chemical‑process enterprises, dedicated chemical process safety engineers are often appointed precisely to build robust technical expertise, offering specialized safety‑related technical assistance to project teams, production units, and maintenance and repair departments.

Clear delineation of security responsibilities is the foundation for establishing an effective system security management framework.

    2. Systematic Safety Management Throughout the Entire Lifecycle of Process Units

The lifecycle of a process unit encompasses research and development, project initiation, design, construction, operation, and decommissioning. Enterprise safety management must be integrated across all these phases; by establishing clear management procedures that define the tasks to be accomplished at each stage and rigorously implementing them, tangible results can be achieved. (To be continued)