work, and related tasks. It was not located near nor was it related to the Tedlar process.
DuPont policy states that the proprietor should be “knowledgeable” about the area they are
signing off on and that the proprietor should “walk down” the area where the hot work is
to be done. On the day of the incident, this was not done.
The contractors would not have known about any of the chemicals present in the Tedlar
area or if they were flammable or combustible; neither did they have knowledge of the
Tedlar process nor if flammable vapors might be present around the slurry tanks. Despite
this they were allowed to complete the hot work permit and begin hot work without getting
approval from any DuPont employee knowledgeable about the process.
Prior to this incident, the DuPont Buffalo facility allowed someone in the service department,
rather than someone knowledgeable about the area, to sign off on contractor work
permits. The individual in the service department who signed as area proprietor had no
knowledge of the Tedlar area or any associated dangers and had been signing permits for
the Mollenberg-Betz contractors for months while they did hot work in other parts of the
Buffalo facility. Information gathered from CSB interviews indicated the DuPont service
worker believed that he was simply releasing them to do their jobs and that the construction
engineer had briefed them on the job and hazards. He was not aware that he needed
to know about potential hazards or that he was not the appropriate DuPont employee to
sign these permits. On the day of the incident the service department worker was still under
the assumption that the Mollenberg-Betz contractors were working on the steam line and
believed that was the purpose of the hot work permit.
DuPont’s policies and procedures are structured to ensure that someone knowledgeable
checks before hot work is performed. However, on the day of the incident, no individual
with plant-specific knowledge of the Tedlar process reviewed the hot work permit. DuPont’s
practices had fallen short of its policies..
4.5 LOCKOUT PROCEDURE
DuPont’s corporate Contractor Safety Handbook requires a lockout procedure to protect
workers from injury caused by energized equipment, the opening of valves, or exposure
to electrical sources. The DuPont Buffalo facility’s Yerkes Contractor Safety Handbook
states that any equipment locked for safety must be deactivated, tagged, cleared, and tried.
Contractors working in a locked out area were responsible for verifying that the lockout
procedure had been completed. The handbook also states that isolating piping systems in
hazardous processes should include block valves or a blind flange. Piping systems were to
be examined after lockout to ensure they were isolated.
DuPont Buffalo’s procedure “Lockout Procedure Lock, Tag, Try, and Think” describes the
lockout/tagout procedures at the Buffalo facility. This document states that “all sources of
hazardous energy shall be removed or controlled prior to potential exposure to the hazards.”
The list of examples of hazardous energy sources does not include chemicals or fire
hazards however the OSHA standard for lockout, Control of Hazardous Energy (29 CFR
1910.147) includes chemicals as energy sources for which a lockout procedure must address
(Section 5.0). DuPont designated the area job representative, usually a DuPont field engineer,
as responsible for securing required lockouts for contractor work. In addition, the field
engineer and the contractor foreman were required to verify that the lockout procedure
was done. The lockout card for slurry tank 1 did not include a requirement for blinding
the overflow line; that is, tank 1 was considered completely “locked out” with the overflow
open to the tank.