Cleaning and Decontamination: Enaex Rio Loa Plant

Managing risk in the explosives industry is an ongoing task that requires a systematic and disciplined approach. Risks are always present, which implies the need for controls and strategies to manage hazards effectively and consistently. This is where activities such as cleaning and decontamination play a fundamental role, not only in ensuring operational safety but also in mitigating risks that could lead to incidents.

Through the SAFEX bulletins we have many examples of incidents in manufacturing plants with valuable lessons learned, where causation was linked to the presence of residual explosives material inadvertently subject to a source of ignition - friction, impact, static or heat.

From industry experience and knowledge, reinforced through the Basis of Safety (BOS) training, we know that sources of ignition must be controlled, and we recall this through the simple but well-known acronym, FISH (friction, impact, static, heat).

When combined with the presence of explosive materials, the unwanted source of ignition represents an unacceptable risk. Cleaning and decontamination become essential activities in reducing the likelihood of accidents by minimizing and removing the presence of residual explosives in work areas and equipment.

Identification of Strengths and Opportunities

At Enaex, Our Priority LIFE’ is a foundation value placing the safety and integrity of our people first. Following recent SAFEX safety alerts, the management team at our Rio Loa facility instigated a comprehensive review of cleaning and decontamination processes throughout the various plants, conducting a thorough analysis of the existing methodologies, comparing them with industry best practice as well as lessons learned from internal operations. Through the review process, several positive aspects were identified, including opportunities for improvement that are worth highlighting.

It was pleasing to note a high level of awareness among workers on the importance of keeping work areas clean and organised. Employees recognised the direct benefits, not just from a safety standpoint but also the operational efficiencies gained from working in a clean environment. This level of awareness reflects ongoing employee training with a focus on BOS, reinforcing the importance of safe practice and individual accountability in explosives handling.

Below, we outline the main recommendations and adjustments implemented in our operations to optimize cleaning and decontamination activities, ensuring they meet the highest standards of safety and operational efficiency.

1) Definitions and Objectives: Differentiating Cleaning and Decontamination

Although both activities aim to keep the presence of explosive materials under control, it is essential to differentiate them to avoid confusion. Cleaning and decontamination are distinct processes in both their methods and specific purposes. This differentiation is crucial to ensure that each activity is carried out correctly and in accordance with its stated objective

• Cleaning is a continuous process aimed at removing any significant accumulation of explosives in work areas and operational equipment. Its primary purpose is to ensure the daily safety of operations by preventing small amounts of explosive material from becoming a cumulative risk.
• Decontamination, on the other hand, focuses on the complete removal or neutralization of all traces of explosive or hazardous substances to allow safe interventions in areas or equipment requiring deeper handling or high-risk maintenance work.

Based on these definitions, we established the following guidelines to ensure that each activity serves its specific purpose:

2. Standardization of Methods: Documented Procedures and Records

A key aspect of improving cleaning and decontamination processes is the standardization of processes and the documentation of each step. Having well-defined and accessible procedures ensures that staff can carry out tasks consistently and in accordance with safety standards. This not only facilitates training but also ensures that any deviation or error can be quickly identified and corrected.

2.1 Cleaning: Three Levels of Intervention

We defined three levels of cleaning, each with its own methodology, frequency, and objectives. This allows for more efficient management of operational areas, ensuring that each intervention is aligned with the risks present and the current operational needs.

2.1.1 Daily Cleaning

Daily cleaning is performed shortly before the end of each shift, with the aim of maintaining continuous control of the accumulation of hazardous substances such as gases, fugitive dust, and process residues. This activity is carried out by operational personnel under the supervision of the lead operator, who distributes tasks and reviews their completion through a checklist detailing critical points of attention. Although execution time is limited, this cleaning is crucial to prevent the accumulation of risks throughout the day.

2.1.2 Shift Change Cleaning

Shift change cleaning is conducted on the last day of the shift and lasts longer. Its purpose is to carry out a more in-depth cleaning, covering areas and equipment that cannot be addressed during the daily routine. If preventive maintenance is scheduled, the removal of raw material stock and finished products is included, with items being transferred to storage magazines. This activity concludes with the issuance of a Clean Area Certificate, which is necessary for the maintenance team to work safely. This entire process is also governed by verification control, along with procedures that support the methodologies and tools required to correctly carry out this process.

2.1.3 Industrial Cleaning

Industrial cleaning is performed during major maintenance shutdowns and is much more thorough than the previous levels. Areas that are difficult to access, such as ventilation ducts, high structures, and the interiors of tanks, are included. This activity requires the involvement of specialized equipment under the supervision of the area’s operational manager. Additionally, before cleaning begins, a risk assessment is carried out, and the corresponding permit is issued, ensuring that all safety standards are met.

2.2 Decontamination: Process and Certification

Decontamination is a more complex process than cleaning, as it involves the removal or neutralization of any trace of explosive or hazardous substances before intervention in an area or equipment. This procedure is critical to ensure the safety of those working in maintenance or repair operations, as well as the personnel performing the intervention.
The steps that we have implemented for the decontamination process are as follows:

• Intervention Request: The request must specify the equipment, required intervention, reason, and execution date.
• Decontamination Method Analysis: The most appropriate method for the explosive substance in question must be evaluated, considering factors such as the type of explosive, the risk of sympathetic propagation or detonation, and the expected quantity of residual material.
• Risk Planning and Evaluation: The intervention is planned, risks are assessed through a job hazard analysis, and the corresponding work permit is issued.
• Decontamination Process Execution: The agreed method of decontamination is completed in line with established process outlined in the work permits and supporting job hazard analysis.
• Decontamination Level Verification: The equipment or area is checked to ensure effective decontamination. If complete decontamination is not possible, this must be noted in the certificate, and the equipment should be labeled with the residual risk level.
• Certificate Issuance and Labeling: A certificate specifying the process details, equipment, applied method, and level of decontamination achieved is issued. The equipment is labeled accordingly: Decontaminated, Not Decontaminated, or Decontaminated with Residues.

3. Control and Verification: Ensuring Compliance with Standards

Once the cleaning and decontamination processes have been implemented and documented, it is essential to carry out periodic control checks to ensure that the defined standards are being met. This monitoring includes both on-site inspections and document reviews, which allow for the identification of potential deviations or areas that may require adjustments.
This article was written following an exhaustive review of our processes at our Rio Loa facility. The catalyst for a more comprehensive review was the many SAFEX safety alerts on incidents that noted cleaning and decontamination as causal factors. The review not only identified strengths, such as employee awareness and commitment to safety, but also areas for improvement that required attention to optimise operational safety.

Conclusion

Cleaning and decontamination in an explosives manufacturing facility are not merely routine tasks, they are critical elements in a robust and effective risk management system. The correct implementation of these activities, along with periodical control checks and regular reviews to continuously improve processes.
Cleaning and decontamination activities must be documented in procedures that include responsibilities, methodologies, frequencies, and record keeping. As we continue to learn from incidents, develop and adjust our practices, the focus on safety must remain the foundation of all our operations, protecting both people and the integrity of our facilities.