Nitrogen Nearmiss

Safety Lesson Learned: Nitrogen Nearmiss
Location of Incident: Bataan Polyethylene, Filipina

Brief Account of Incident
As part of preservation of plant equipment, the Closed Cooling Water System of the extruder barrel was placed under nitrogen. On April 28 the moisture and oxygen levels in the system were monitored to be higher than the acceptable level. The Night Shift Team handed over its recommendation to address the problem to the incoming April 29 Day Shift Team. The day Shift Operations Team decided to do nitrogen pressure swing to bring the down the level of contaminants.

Two Technicians were assigned to the task. During the purging nitrogen was being discharged inside the Additive and Pelletizing building with all access doors open (natural ventilation) but exhaust fans in a shut off condition (no forced ventilation). The point of nitrogen release was less than 2 feet away from the Technicians. The Technicians were using a gas tester. The activity area was not barricaded. The activity was observed during an Advanced Safety Audit tour and was stopped immediately. A Team was immediately formed to conduct the investigation.

What Went Wrong
1. No comprehensive Job Safety Analysis and/or Risk Assessment was performed by the Team prior to the start of the activity.
2. Non-compliance with existing Operating Instructions covering (temporary) preservation related activities.
3. Inadequate communication of established Operating Instructions.
4. Established Instructions and guidelines for nitrogen purging activities do not adequately address all related HSE concerns.
5. Insufficient awareness of people performing the tasks on the imminent danger of nitrogen.

What Went Well
1. The activity was observed and assessed during a regular Advance Safety Audit (ASA).
2. The activity was immediately stopped. As a result, there were no cases of fatality nor injury.
3. Investigation Team was immediately formed.

Safey Lesson Learned
1. Review Procedures and Guidelines to ensure individuals and working teams do perform the appropriate risk assessment prior to starting a new or revised activity.
2. Ensure everyone's compliance to established Work Standing and Operating Instructions (WSI/WOI).
3. Ensure that all established Operating standing Instructions, including temporary equipment preservation instructions, adequately address Safety requirements and concerns.
4. Ensure an approved HSE Plan is available for activities like extended plant preservation.
5. Ensure sufficient knowledge and total awareness of each individual and working teams to different hazards in the workplace especially when handling hazardous materials (N2).
6. Risk management assurance processes need to recognise the degree of competency within the operating team / supervisory staff and also recognise organisational change (for example resignations).