Share on Facebook!

Blast Resistant Structure for Petro Chemical Plant Application

Blast Resistant Structures and Buildings are truly the best action to take while providing the safest enclosures for your employees and equipment.

Blast Resistant Structure, Shell Chemical Mobile Laboratory,
Blast Resistant Structure, Shell Chemical-CRI Mobile Laboratory,
completed by Clegg Industries, Feb. 2007. Click for more information



For information on manufacturing a blast resistant structure
please contact John Clegg at (361) 578-0291.

Urgent Recommendation


1. On March 23, 2005, the BP Texas City refinery experienced a severe explosion
and fire accident involving a raffinate splitter tower within the isomerization
(isom) unit and associated blowdown system that resulted in 15 deaths, 170
injuries, and significant economic losses; the accident was one of the most serious
U.S. workplace disasters of the past two decades.

2. All of the fatalities and many of the serious injuries occurred in or around the nine
contractor trailers that were sited near process areas and as close as 121 feet from
the isom unit. This unit contained large quantities of flammable hydrocarbons
and had a history of releases, fires, and other safety incidents over the previous
two decades.

3. Workers in adjacent units were injured in trailers as far as 480 feet from the isom
blowdown drum. A number of trailers as far as 600 feet from the blowdown drum
were heavily damaged.

4. At the Texas City refinery, trailers had been periodically sited in and around
hazardous process areas for reasons of convenience such as ready access to work
areas. The trailers did not need to be located as close as they were to the process
areas in order for workers to perform their job duties.

5. Trailers had been sited periodically in the same location near the isomerization
unit for a number of years. On September 1, 2004, and prior to a safety
assessment, BP placed the trailer where 12 workers died near the isomerization
unit; a month later BP applied a siting policy to approve the location. The eight
other trailers placed nearby were not analyzed for hazards related to their location,
nor was the impact of the total occupancy of multiple trailers in close proximity

6. Under BP’s siting policy, trailers used for short periods of time such as
turnaround trailers were considered as posing little or no danger to occupants.
This approach conforms with the guidance provided in American Petroleum
Institute (API) Recommended Practice 752, “Management of Hazards Associated
with Location of Process Plant Buildings.” API 752 states that each company
may define its own risk and occupancy criteria.

API 752 is a widely recognized practice for complying with facility siting
requirements under the Process Hazard Analysis element of OSHA’s Process
Safety Management Standard (29 CFR 1910.119).

8. API 752 provides no minimum safe distances from hazardous areas for trailers
used in refineries and other chemical facilities. Trailers are not generally designed
to protect the occupants from the fire and explosion hazards present in refineries.
In contrast, occupied buildings (e.g. control rooms, operator shelters) located
within a process unit are typically permanent and constructed to be blast and fire

Trailers can be easily relocated to less hazardous sites. Subsequent to the March
23rd incident, BP America Inc. announced that it would move trailers at least 500
feet from hazardous process areas. A number of contractor offices were moved to
an offsite location.

10. In 1995, another serious process plant incident involved occupied trailers placed
too close to hazardous areas, resulting in significant deaths and injuries. At the
Pennzoil Refinery in Rouseville, Pennsylvania, a hydrocarbon fire that resulted
from the bursting of two storage tanks led to five fatalities, including two
contractors who were in trailers sited near the tanks. A 1998 EPA investigation
report determined that if the trailers had been isolated from the storage tank area
the casualties may have been prevented.

11. Under 42 U.S.C. §7412(r)(6)(C) (ii), the Board is charged with “recommending
measures to reduce the likelihood or the consequences of accidental releases and
proposing corrective steps to make chemical production, processing, handling and
storage as safe and free from risk of injury as is possible ….”

Board procedures authorize the issuance of an urgent safety recommendation
before a final investigation report is completed where there is a likelihood that a
safety issue is widespread at a number of sites.


Pursuant to its authority under 42 U.S.C. §7412(r)(6)(C)(i) and (ii), and in the interest of
promoting safer operations at U.S. petrochemical facilities and protecting workers and
communities from future accidents, the Board makes the following urgent safety

American Petroleum Institute

In light of the above findings concerning the March 23rd incident at BP’s Texas City
refinery, revise your Recommended Practice 752, “Management of Hazards
Associated with Location of Process Plant Buildings” or issue a new Recommended
Practice to ensure the safe placement of occupied trailers and similar temporary
structures away from hazardous areas of process plants. Ensure that the new
recommended practice:

* Protects occupants from accident hazards such as heat, blast overpressure, and

* Establishes minimum safe distances for trailers and similar temporary
structures away from hazardous areas of process plants;

* Evaluates the siting of trailers under a separate methodology from permanent
structures, since trailers are more susceptible to damage, are more readily
relocated, and likely do not need to be placed near hazardous areas.

American Petroleum Institute and the National Petrochemical and Refiners

Issue a safety alert to your membership to take prompt action to ensure the safe
placement of occupied trailers away from hazardous areas of process plants.

For information on manufacturing a blast resistant structure
please contact John Clegg at (361) 578-0291.

Clegg Industries, Inc., a manufacturer of specialty vehicles, trailers and special structures for defense and industry
16400 Northwest Zac Lentz Parkway . Victoria, TX 77905 . (361) 578-0291 . FAX (361) 578-5908

Copyright 2000 Clegg Industries, Inc.