The fatal confined space accident I found this month was particularly disturbing to me. It seemed so blatantly obvious that the space and work being performed would require at least some basic confined space entry procedures, yet none appear to have been followed.
A company that cleans industrial tanks was hired to clean the bottom of a 40 x 50 foot 6000 gallon tank that previously contained the highly toxic solvent, methylene chloride. It appears that he “fell” into the tank, and was found unconscious at the bottom. The 15 towns responding to the incident with fire/hazmat/rescue personnel, very quickly realized after testing the tank’s atmosphere that the 12% oxygen level meant that this would be a body recovery and not a rescue. They then proceeded to take the necessary precautions to protect rescue workers from suffering the same fate as the 37 year old worker.
While this fatality is still under investigation by OSHA it is clear that there were some major problems with this confined space entry. It appears that not just some, but ALL of the basic confined space entry procedures were ignored. If even ONE of the basic confined space entry procedures had been followed this worker may be alive today. It appears that no gas monitoring was performed prior to entry. If it had been, the oxygen alarm would have sounded indicating that the atmosphere required ventilation prior to entry. If the atmosphere had not been tested, even if the worker had been attached to a tripod, harness, winch rescue system, he likely would not have fallen or if he did, his coworker could have pulled him out. And sadly, it appears that the worker was not wearing the proper PPE for entry. A half-mask air purifying respirator was found near his body. Air purifying cartridge respirators do NOT protect against methylene chloride exposure and NO air purifying respirator protects against an oxygen deficient environment. If the worker did need to enter the tank to clean the residue while the atmosphere was still unsafe, he would have needed to wear a self contained breathing apparatus or an airline respirator with an auxilary self contained breathing supply. Further information on the fatal accident can be found on the web.
The question I have is why would an experienced industrial cleaning company worker have entered this tank without a confined space permit, air monitoring, ventilation and non entry rescue capability? Something just does not seem right. An industrial tank cleaner (and certainly his employer) should have recognized this was a confined space and should followed at least some basic confined space procedures. The company website discusses confined space as one of their specialties so this was not a company that was unaware of the hazards of this type of work.
The medical examiner has now reported that the worker died of head trauma from the fall. I have to wonder if perhaps the worker was overcome by methylene chloride vapors in the space ADJACENT to the tank opening and if he fell into the tank before he had a chance to assess the hazards and to follow some basic permit required confined space procedures. The worker’s partner never entered the tank but was also taken to the hospital with symptoms, leading me to believe that he was exposed to methylene chloride vapors in the adjacent space outside the tank opening. The Agency for Toxic Substances and Disease Registry (ASTDR) lists methylene chloride as a material that causes dizziness and unsteadiness. ASTDR indicates that even at low levels of exposure, workers may become less attentive and less accurate at tasks requiring hand eye coordination.
Unfortunately hazards of adjacent spaces are not generally recognized and are not covered in OSHA’s permit required confined space entry standard. The Chemical Safety Board has noted the hazards of adjacent spaces in some of their investigations, including the Valero Case, and has encouraged NFPA to address adjacent spaces in their Best Practices Document currently in development.
The NFPA Technical Committee on Confined Spaces is working on the development of a best practices document on confined space entry designed to address gaps in existing confined space standards. This document will go beyond the regulatory requirements and provide more prescriptive guidance on how to safely enter, work and exit from a confined space. The recognition and control of adjacent space hazards will be included in this document. Do you have any thoughts on how to address adjacent space hazards or other ideas for what should be included in the document? If so please leave a comment or contact npearce@ nfpa.org.