HSE management system for risk control in plant shutdowns

The HSE management system is the structural backbone for controlling risks during plant shutdowns, especially in STO (Shutdown–Turnaround–Outage) events, where simultaneous interventions, contractor involvement, and exposure to hazardous energies increase. In these contexts, safety no longer depends on isolated procedures but requires a risk-based architecture that articulates people, processes, and operational decisions.

The proper integration of the permit to work (PTW), process safety management (PSM), occupational risk analysis, and international regulatory compliance determines whether a shutdown is executed under control or, conversely, leads to operational and regulatory failures.

Critical risks in plant shutdowns (STO)

Increased operational risk in STO

Plant shutdowns (STO) represent one of the highest risk exposure moments in energy and industrial facilities. During these events, critical equipment is intervened, operating conditions are modified, and multiple activities are carried out in parallel, generally under schedule pressure.

Hot work, line openings with possible residual hydrocarbon presence, confined space interventions, electrical isolations, and lifting operations may coincide within the same operational period. This convergence increases the probability of interference and requires a higher level of technical coordination.

The incorporation of contractors and temporary personnel adds variability in competencies and safety culture. Without a structured and risk-aligned HSE management system, these conditions can quickly evolve into major events.

Impact of HSE failures in shutdowns

Failures in management during an STO are not limited to occupational injuries. In high-risk environments, they can trigger uncontrolled energy releases, fires, or environmental impacts with operational and reputational consequences.

From a PSM perspective, a poorly controlled intervention may compromise critical barriers and affect asset integrity before restart. The difference between normal operation and a plant shutdown is therefore structural, not circumstantial.

The following comparison in Table 1 summarizes how the risk level varies during an STO and why the HSE management system requires specific reinforcement during these phases.

Table 1: Normal Operation vs STO (Risk Level)

Variable	Normal Operation	Plant Shutdown (STO)
Process Conditions	Stable and controlled	Modified or temporarily outside design
Task Simultaneity	Limited	High concentration of critical activities
Contractor Participation	Moderate	High and multidisciplinary
Operational Interference	Low	High
Exposure to Hazardous Energies	Controlled under active barriers	Increased due to openings and interventions
Level of Supervision Required	Standard	Reinforced and continuous
Probability of Deviations	Controlled	Increased due to schedule pressure
Systemic Risk Level	Moderate	High if there is no structured control

This variation in the operating environment confirms that risk management during an STO requires a more robust HSE architecture, integrated with critical controls, process safety management, and intensive field supervision.

HSE management system architecture in STO

Components of the HSE management system

An HSE management system applied to plant shutdowns functions as an organizational structure designed to anticipate, control, and verify risks before, during, and after the shutdown. It is not limited to isolated procedures; it articulates technical planning, operational supervision, and document control within a coherent framework.

During an STO, this architecture requires a higher level of control that includes:

• Clear definition of responsibilities.
• Prioritization of critical activities.
• Intensive field supervision.
• Traceability and document verification.

When these elements are not aligned, management tends to fragment, increasing the probability of operational deviations.

Risk-based approach in STO

The risk-based approach articulates the system architecture during shutdowns. Its purpose is to anticipate hazards before execution and allocate resources based on potential impact.

In an STO, this involves evaluating interference between simultaneous tasks, classifying activities according to criticality, and establishing preventive and mitigative barriers. Tools such as occupational risk analysis and job safety analysis (JSA) are integrated within this structured framework.

The assessment is not limited to each individual task. It also considers systemic effects that could compromise asset integrity or operational stability.

Process safety management in STO

During a shutdown, process safety management (PSM) takes on a decisive role. Isolations, temporary modifications, and openings of pressurized equipment must be rigorously controlled to protect critical barriers.

The integration between the HSE management system, process safety management, and the permit to work ensures technical coherence in highly complex environments.

In an STO, prevention operates at multiple complementary levels. The HSE management system defines governance, process safety management protects critical barriers, and the PTW controls the execution of specific tasks.

Table 2: HSE + PSM + PTW Integration in STO

Component	Level of Control	Function in STO
HSE Management System	Strategic	Governance, planning, and comprehensive supervision
Process Safety Management (PSM)	Technical	Protection of critical barriers and control of hazardous energies
Permit to Work (PTW)	Operational	Authorization and control of specific tasks
Occupational Risk Analysis	Preventive	Identification and prioritization of hazards
Job Safety Analysis (JSA)	Tactical	Step-by-step validation of critical activities

This articulation prevents risk control from being dispersed across areas. In complex shutdowns, structured coordination between HSE, processes, and permits is decisive for maintaining operational stability.

Critical HSE controls in plant shutdowns

During an STO, critical controls act as technical and administrative barriers intended to prevent high-impact events. Not all have the same operational relevance; priority should be given to those whose failure could compromise asset integrity or personnel safety.

Among the most relevant are:

• Verified mechanical and electrical isolations.
• Formal application of LOTO procedures.
• Atmospheric control in confined spaces.
• Strict management of hot work.
• Reinforced supervision of simultaneous tasks.

The effectiveness of these controls depends on prior validation and operational discipline in the field. Relaxing standards during the shutdown significantly increases the probability of major incidents.

Occupational risk analysis in STO

Occupational risk analysis makes it possible to identify hazards associated with each scheduled activity. During a shutdown, it must consider not only the individual task but also interaction with other ongoing activities.

It is recommended to:

• Conduct prior criticality assessment.
• Identify operational interferences.
• Apply the hierarchy of controls.
• Clearly assign responsibilities.

The risk-based approach facilitates prioritizing resources where potential impact is greatest.

Job Safety Analysis (JSA)

Job safety analysis complements the general risk assessment through the step-by-step breakdown of critical activities. It is especially relevant in hot work, confined spaces, or lifting operations.

The integration between critical controls, occupational risk analyses, and JSA reinforces preventive coherence during industrial shutdowns.

This video complements the critical controls section, offering a practical view of key operational safety elements during plant shutdowns. Source: HSE STUDY GUIDE.

Permit to work in safe shutdowns

PTW governance

The PTW constitutes one of the most relevant administrative controls during an STO. It is not limited to authorizing tasks; it ensures that technical and operational conditions have been verified before intervention.

In plant shutdowns, the system must contemplate:

• Validation of physical and energy isolations.
• Confirmation of safe atmospheric conditions.
• Evaluation of interference with simultaneous activities.
• Formal approval by designated responsible parties.

PTW governance requires document traceability, validity control, and technical closure before restarting the intervened system.

Integration of PTW with JSA and risks

The PTW does not operate in isolation. It must integrate with occupational risk analysis and JSA, ensuring that each identified risk has verifiable preventive measures.

In complex shutdowns, inconsistency between risk assessment and authorizations can lead to interventions under uncontrolled conditions.

Digitalization through HSE management software strengthens PTW control by improving visibility of active permits, identifying interferences, and maintaining an audited history of authorizations.

In complex industrial environments, this digital integration contributes to reducing human errors and improving real-time decision-making.

HSE management software in shutdowns

HSE management software has become an essential component for managing the operational complexity that characterizes plant shutdowns. In STO events, where multiple critical tasks converge, digitalization allows centralizing technical information, active permits, and risk analyses within a single platform.

Its main functions include:

• Centralized permit to work management.
• Monitoring of occupational risk analyses and JSA.
• Updated document control.
• Real-time indicator monitoring.
• Recording and analysis of operational deviations.

Beyond replacing paper forms, the value of the system lies in integrating operational data under a risk-based approach.

The following scheme in Table 3 summarizes how a digital system strengthens operational control during an STO.

Table 3: Digital Workflow of the Permit to Work

Stage	Action	Validation
Request	Digital registration of activity	Technical responsible party
Evaluation	Associated risk analysis	HSE Supervisor
Approval	Formal authorization	Area Manager
Execution	Real-time monitoring	Field Supervisor
Closure	Confirmation of safe conditions	Document Control

This structured workflow improves traceability, facilitates regulatory audits, and reduces interference in environments with high operational simultaneity.

Regulatory framework of HSE in STO

Risk management during plant shutdowns must align with international regulatory frameworks that establish clear requirements regarding occupational safety, environmental protection, and control of hazardous energies.

Standards such as ISO 45001 structure the systematic management of occupational health and safety. ISO 14001 regulates environmental aspects associated with industrial interventions. In process safety, OSHA 29 CFR 1910.119 (PSM) requires formal control of hazardous energies and maintenance of critical barriers.

OSHA 29 CFR 1910.147 regulates energy control through LOTO procedures, fundamental during shutdowns. API RP 754 complements these frameworks through technical performance indicators.

Regulatory convergence requires the HSE management system to operate as an integrating structure capable of articulating occupational safety, process safety, and documentary compliance.

The following comparison summarizes the most relevant regulatory frameworks and their practical application in industrial shutdowns.

Table 4: Regulatory Comparison Applicable to STO

Standard / Regulation	Main Focus	Application in STO
ISO 45001	Occupational safety	Structured risk management
OSHA 1910.119 (PSM)	Process safety	Control of hazardous energy
API RP 754	Performance indicators	Event monitoring
OSHA 1910.147 (LOTO)	Lockout/Tagout	Verified isolations
ISO 14001	Environmental management	Emission control during shutdown

Coordinated compliance with these frameworks is decisive for executing shutdowns without compromising operational continuity or asset integrity.

Deviation management and system integration in STO

During a plant shutdown, technical deviations associated with scope changes or unforeseen conditions may arise. Structured management of these variations prevents a specific modification from compromising critical barriers.

An effective HSE management system requires that every deviation be documented, evaluated, and approved before implementation.

System integration throughout the entire STO cycle begins in planning, continues with disciplined execution, and culminates in technical closure. Consistency between these phases sustains operational reliability in high-demand environments.

Technical closure is not limited to verifying intervened equipment. It involves confirming safe startup conditions and consolidating lessons learned with a critical perspective. These must be formally integrated into existing procedures so that each shutdown contributes to strengthening future interventions and elevating organizational maturity.

In complex shutdowns, coherence between planning, execution, and post-evaluation ultimately sustains operational reliability.

Conclusions

Plant shutdowns constitute one of the most technically complex scenarios in the energy industry. The simultaneity of interventions and the temporary modification of operating conditions require structured control that goes beyond the isolated application of procedures.

The disciplined application of an HSE management system, articulated with critical controls and formal authorization mechanisms, reduces the probability of major incidents. It is not merely about regulatory compliance, but about sustained technical coherence throughout the entire shutdown cycle.

In demanding industrial environments, system maturity prior to each STO makes the difference between a controlled intervention and an event with significant operational impact.

References

1. International Organization for Standardization. (2018). ISO 45001:2018 occupational health and safety management systems — Requirements with guidance for use. ISO.
2. Occupational Safety and Health Administration. (2023). Process safety management of highly hazardous chemicals (29 CFR 1910.119). U.S. Department of Labor.
3. Occupational Safety and Health Administration. (2023). The control of hazardous energy (lockout/tagout) (29 CFR 1910.147). U.S. Department of Labor.
4. American Petroleum Institute. (2016). API recommended practice 754: Process safety performance indicators for the refining and petrochemical industries. API.
5. Center for Chemical Process Safety. (2019). Guidelines for risk based process safety. John Wiley & Sons.

Frequently Asked Questions about HSE in STO