A vague scope of work hindered the hazards review and control process; this resulted in skin exposure to acid for two laboratory workers.
Effects of Incident
Exposure to acid and resulting skin burns - necessitating hospitalization.
Three laboratory workers were exposed to strong acids ejected from a chemical reactor vessel. Two experienced acid burns on their faces, extremities, and torsos that resulted in hospitalization. Ejection of the acids was a result of an unanticipated exothermic reaction initiated by the rapid addition of fuming sulfuric acid to the reaction vessel’s contents.
The incident investigation revealed that the project’s work planning document did not adequately describe the planned activities. The work instructions authorized the use of the fuming sulfuric acid, but no information was provided on how or when it was to be used. This lack of specificity prevented relevant subject matter experts from understanding the full scope of the operation and, therefore, they could not fully evaluate the associated hazards and identify effective process and hazard controls.
Corrective Actions to Prevent Reoccurrence
Define work at the task level in a step-by-step manner with sufficient detail and clarity to allow the work planning process to:
Identify hazards associated with the work,
Select and implement appropriate controls,
Develop necessary schedules and priorities, and
Prepare work instructions that ensure the personnel performing the work understand the tasks, hazards, and controls necessary to complete the work safely.