Page 4 - Common Elements - CCPS Safe Work Practice

Call to Action

The US Chemical Safety Board (CSB) investigates significant incidents in the process industries that occur in the US.
CSB reports often include recommendations related to deficiencies in the Permit to Work system that contributed to
the incident. Examples are provided below:

Hot Work Explosion
Two contractors were performing welding atop a slurry tank when hot sparks ignited flammable vapors inside the
tank, causing an explosion that killed one contractor and seriously injured another.
Recommendations Related to Permit Process: Develop and enforce corporate-directed policies and procedures
which will require all facilities to audit their hot work permitting systems prior to initiating hot work to ensure that:

g All potential explosion hazards associated with hot work activities are identified and mitigated.
g All relevant forms required for permits are completed in accordance with corporate policies
and industry standards (including NFPA 326 and NFPA 51B).
g Appropriate personnel officially approve hot work permits, by signature or equivalent,
consistent with corporate policies.

https://www.csb.gov/e-i-dupont-de-nemours-co-fatal-hotwork-explosion/

Nitrogen Asphyxiation
Two contract employees were overcome and fatally injured as they performed maintenance work near a 24-inch (61
cm) opening on the top of a reactor. One of the workers died attempting rescue.
Recommendations Related to Permit Process: Conduct safe work permit refresher training for all permit preparers
and approvers and affected refinery personnel and contractors. Emphasize the following items:

g All proposed work requires a jobsite visit by the requestor and a unit operator to identify
special precautions, equipment status, and personal safety equipment requirements.

g The permit must clearly identify all hazards and special personal protective equipment requirements.
g Audit work permit procedures and nitrogen purge safety procedures at each U.S. refinery.
Determine if issues identified in this Case Study are occurring elsewhere. Implement corrective
action, including training, where necessary.
g The Permit contained a status box for “Nitrogen Purge or Inerted” with potential answers
of “Yes/No/Not Applicable.” Define the conditions for marking this status box.
https://www.csb.gov/valero-refinery-asphyxiation-incident/

4 COMMON ELEMENTS OF PERMIT TO WORK SYSTEMS, SAFE WORK PRACTICES, AND PERMITS