Lesson Learned/Best Practice Briefing


TitleSubcontractor work stabilizing sodium amide results in fire, activation of a fire sprinkler within a fume hood, and an operational disruption

EventLBNL Event

Event Date08/07/2018

CategoryESH-Chemical - Business Continuity, Emergency Management-EOC Team, Fire Protection Systems & Equipment, Chemical Hygiene-General, Corrosives, Peroxide Formers, Water Reactives, Hazardous Waste Generation-Research Areas

Subcontractors are occasionally hired to stabilize high-hazard chemical waste. In the event described in this Lessons Learned, the work planning did not identify and control all hazards, nor did it take into account possible downstream consequences of a mishap. Additional contingency planning with increased stakeholder involvement would have minimized operational disruption and property damage resulting from this incident. Lastly, when a subcontractor or any lab employee recognizes an inability to follow the approved formal work plan, a Stop Work Authority should be issued.

Actions to Prevent Recurrence
Environment, Health and Safety (EHS) Division review and identification of high-hazard chemicals is an ongoing effort. In July of 2018, EHS Staff identified sodium amide as a high-risk, inorganic peroxide-forming chemical. Sodium and other alkali metal amides are highly sensitive to oxidation in air which can lead to the formation of unstable and potentially explosive mixtures of the alkali nitrite, hyponitrite, hydroxide, and carbonate(REF1). Sodium amide, generally used in synthesis as a strong base, is also water-reactive, corrosive, shock, friction, and temperature sensitive, and has a shelf life of three months.

A chemical management system (CMS) inventory search identified three containers ranging from 4 to 13 years old on site. EHS staff worked with the chemical owners to locate the containers and secure access. EHS led the coordination of work planning with a reactive materials subcontractor who was retained to stabilize and treat the containers under an Emergency Permit from the California Department of Toxic Substances Control (DTSC). Draft planning documents were shared with stakeholders in advance of the stabilization. Final documents were provided the day of the stabilization. The subcontractor Health and Safety Plan (HASP) stated that they would provide all equipment necessary to complete the work. A Subcontractor Job Hazards Analysis (SJHA) form was completed; however, it did not identify that there was a risk of fire/explosion, which would have triggered additional subject matter expert review.

During the work planning, the Division EHS Manager inquired about the use of the bomb squad for this project. The bomb squad was available and willing to remove the containers, at no cost to the laboratory, and there was line-management support for this option within the impacted division. EHS discussed the use of the bomb squad and decided the reactive materials subcontractor was appropriate for the work.

When the reactive materials team arrived on the evening of August 7th to perform the work, they had not been fully briefed by the subcontractor's manager of field services. The manager had planned to attend, but notified EHS he was unavailable earlier that day. In addition, the team did not bring the equipment that was listed in the work plan. This was a missed opportunity to issue a Stop Work Authority.

During the pre-job meeting, attendees decided that an empty fume hood located near one of the sodium amide containers was suitable for the treatment site. Some stakeholders who were involved during the pre-work planning stages were not informed of the proposed change in work plan, and therefore did not have the opportunity to provide feedback on the decision to perform work in the fume hood.

The subcontractor set up a portable glovebag with a nitrogen atmosphere and donned the appropriate personal protective equipment (PPE). The team established a 50 ft. exclusion zone around the work site. Fire department personnel were on standby on the floor directly below the work site. When the subcontractor opened the first container of sodium amide inside of the glovebag, there was an immediate flash fire which reached the top of the hood opening and lasted approximately 3-4 seconds.

Fortunately, the subcontractor was not injured. Approximately 5 seconds later, the fire sprinkler within the fume hood activated, which in turn activated the fire alarm system. Firefighters shut off the main water valve in approximately 8 minutes, during which an estimated 800 gallons of water flowed, flooding the upper 4 floors of the building. The member of the subcontractor team acting as a safety watch had been instructed to activate the fire alarm pull-station in an emergency, however, it was later determined that the pull-station was not used. No one dialed 911. Although firefighters were already on-site, calling 911 is important to ensure proper notifications, availability of resources, and effective communication during emergency response.

Recovery efforts began around 10:00pm and continued into the night. A water cleanup crew was brought in to vacuum up water in labs that were cleared of chemical and electrical hazards. During clean up operations and building walk-throughs, it was discovered that water reactive chemicals stored directly below the fume hood where the incident occurred had become submerged in water, although no adverse reactions were observed. Additionally, two sodium amide containers remained in the flooded building.

The Emergency Operations Center (EOC) was activated August 8th, 2018 at 9:00 am to coordinate removal of the remaining sodium amide and other water reactive chemicals with the assistance of the bomb squad. The fire department used the Emergency Response Guidebook to establish a 300-foot exclusion zone, the default radius for unknown chemicals. This resulted in the evacuation and closure of 8 buildings while the work was completed. On August 9th, the building was cleared for re-entry with the exception of several labs which were heavily impacted by water intrusion from the fire sprinkler. All labs re-opened over the next few weeks.

Some critical lessons learned include:

• Consider all available options for planning high-hazard work and perform a risk-based analysis. Subcontractor equipment, standard operating procedures, etc. need to provide the highest possible protection of life, health, lab property, and the environment.

• Changes to work scope should be avoided, but if necessary, need adequate prior review by EHS, Subject Matter Experts (SMEs), Activity Leads, and other relevant stakeholders. Be wary of changing plans "on the fly," particularly for high-hazard work. This frequently leads to unintended adverse consequences or issues.

• Identify local water shutoffs. The sprinkler in the fume hood that caused the flooding had to be capped at the source after the water to the building was shut off. A sprinkler shut off for the floor was available and would have reduced the amount of water released if used.

• Always call 911 if there is a fire, fire sprinkler activation, or if a pull station is used. This ensures proper fire department response.

• Sodium amide did not have specific policy requirements as a time-sensitive chemical until discovery in the chemical inventory. When it was identified, EHS informed the impacted division that the aged containers required action. EHS identification of high-risk chemicals is an ongoing effort, but these lists are subject to change as accuracy is improved. Use safety data sheets, primary literature, and other sources of reliable information to identify high-hazard chemicals in your work area.

• LBNL has specific policies for managing organic peroxide-forming chemicals and additional time-sensitive chemicals. Institutional requirements for time-sensitive chemicals need to be effectively communicated to the lab community. Chemical owners, activity leads, and workers need to understand their responsibilities and ensure chemicals are managed according to these policies. Safe chemical usage is a line management responsibility. Oversight of safety for high-risk chemicals should be prioritized.

• Lab personnel need to issue Stop Work Authorities when there is a change in the scope of any high-hazard work.

Key corrective actions that are in progress to prevent recurrence include:

1) Implement a formal Activity Manager Work Planning and Control process for the management of expired chemicals that require treatment and stabilization prior to disposition as hazardous waste. Develop procedures that describe a process of comprehensive hazard analysis, stakeholder input and approval, clear requirements for Safe Work Authorization, and integration with the SJHA process for Subcontractor performed work.

2) Develop a formal policy for storage, use, and disposal of inorganic peroxide-forming chemicals. The most common inorganic peroxide-forming chemicals are potassium metal, potassium amide, and sodium amide.

REF1: "Chemistry of the alkali metal amides" Chem. Rev. 1933, 12, 1, 43-179.

Lessons Learned are part of the ISM Core Function 5, Feedback and Improvement. Applicable Lessons Learned are to be considered during working planning activities and incorporated in work processes, prior to performing work.
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