Recently, we were involved in a serious incident in which a group of contractors was overcome by a “highly toxic gas” (as defined by the state’s Fire Code) that escaped from a compressed-gas cylinder. This container, along with 42 other containers with various hazardous materials, was stored outside in an unmarked area. The contractors had decided this area would make for a great setup area. After all, how many of us have been around compressed gas cylinders in our careers? Far from the area having the proper hazard warning signage, the storage area was UNCOVERED, and this will play a significant role in this event. The state fire code for compressed gases, Chapter 53, states the following:
5303.14 Overhead Cover
Compressed gas containers, cylinders, and tanks are allowed to be stored or used in the sun except in locations where extreme temperatures prevail. Where extreme temperatures prevail, overhead covers shall be provided.
Does anyone want to participate in a “survey” where we ask 100 safety and hazardous materials professionals to quantify “extreme temperatures”? Care to take a guess at the range we would get from the responses?
Everyone involved in this investigation, even the site EHS team, agreed that the 110F temps that day caused the PSV on the cylinder to relieve pressure, and the gas is 2X’s heavier than air. This storage area was in a “courtyard,” so air movement was restricted. Although the contractors all smelled “something”, they assumed they were OK since they were not near one of the process areas and “smells at this place are common”.
So the SFM took issue with the lack of an overhead cover over these cylinders, which then gave way to multiple lawsuits from the contractor workers who were involved, as well as the contractor company that employed them! The $2,300 metal-vented overhead cover installed after the event would have prevented it and all the fallout. Workers are fine, recovered 100%, but the business’s reputation with the community, state, and federal regulators has been beaten up a bit. But to the business’s credit, they took this learning and required ALL their facilities to have an “Overhead Cover” made of non-combustible materials and VENTED over all cylinder storage locations. We could never agree on the temperature that would qualify as “extreme,” so the business just required it for ALL compressed gas cylinder storage areas. And next year we have it on our audit plan to audit this corrective action during our OSH and PSM/RMP audits.