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Notable Confined Spaces - Solvent Evaporation in an Isolated Subsurface Structure and a Fatal Case of Soil Gas Migration Into a Sampling Shed (AIHce EXP 2021 OnDemand)

Course Description:
Recorded at AIHce EXP 2021

This education session will present two case studies involving gas migration into a confined space. The first presentation will discuss the evaporation of a small volume of a volatile solvent and exchange of the contaminated atmosphere with the external atmosphere through opening(s) in the manhole cover. There is a need for extreme caution around hatches opened for sample collection from vessels containing volatile liquids and when inserting ventilation ducts in preparation for entry of vessels holding residual vapors. The second presentation will outline how a simple change in an open ditch resulted in the migration of soil gases into a sampling pit in a small shed which resulted in the death of a worker and 3 rescuers including 2 EMTs.

Learning Outcomes:
Upon completion of the session, the participant will be able to:

  • Identify hazardous conditions found in subsurface structures.
  • Develop a system to study the atmosphere in a subsurface structure.
  • Discuss prevention of an ignitable atmosphere in the subsurface structure.
  • Recognize the hazards of soil gas migration into a subsurface structure.

Contact Hours:

Presentation Date:

Neil McManus, DSc, CIH, ROH, CSP