1. The problems associated with a high-risk occupancv in one
jurisdiction. creating a problem in a different jurisdiction. present obvious
challenges for emergency planning response agencies.
In this case the responding agencies worked well together, but the
deficiencies of the regulatory and planning processes were a major focus of
attention after the incident.
2. The Incident Command Svstem (ICS) proved to be extremely
effective in this incident. particularly in coordinating the efforts of several
different agencies at the scene.
The ability to assign major responsibilities to command officers from
different fire departments, without any problems, is evidence that the
personnel are trained and prepared to operate effectively.
3. The lack of effective radio communications between agencies was a
problem at this incident.
Cellular telephones were used very effectively to supplement public
safety radio capabilities and proved to be reliable under these
circumstances. In other situations cellular telephone service has been
compromised by the number of persons trying to use the systems under
emergency conditions and particularly the heavy use of the systems by news
media personnel. The location and time of day may have been key factors
in making the cellular network responsive in this incident. Note: Centel
Cellular will block off communications allowing only emergency personnel
phones to work if the system starts to overload.
4 . The decision between evacuating residents and warning them to
remain indoors. with windows and outside air inlets closed. is often critical.
In this case, it was considered more practical to keep patients inside
the hospital than to expose them to the outside atmosphere. This took into
consideration the susceptibility of the patients to chlorine exposure, the
ability to exclude outside air from the ventilation system and the
availability of medical personnel and equipment inside the hospital. Some
area residents reported that they were notified to evacuate and were
exposed to the chlorine cloud while waiting for busses to pick them up.
The risk of exposure during evacuation may have been greater than the
risk if they had remained indoors.
5 . The use of busses operated by fire department personnel is a
practical means to evacuate residents.
It is more feasible to have firefighters drive busses than to train bus
drivers to use SCBA. It is equally difficult for firefighters using SCBA to
convince residents to expose themselves to the outside atmosphere in order
to evacuate, unless the residents are already in distress. The contingency
plan, sending a crew of SCBA-equipped firefighters on a bus to enter and
evacuate an area in immediate danger, is a practical innovation.
6 . Police officers. who are not orovided with or trained to use SCBA.
were effective in evacuating areas ahead of the contamination. but could
not function in the contaminated areas.
Several police officers who were assigned to traffic control or to
assist with evacuation were exposed to the chlorine cloud and transported
themselves to medical facilities for evaluation in the later stages of the
incident.
7. Due to the relatively low concentration of chlorine in the gas cloud.
in this case. the oredominant medical condition was limited to short
duration respiratory irritation.
Chlorine is detectable by odor at very low concentrations and is a
respiratory irritant between 3 and 30 ppm. Individuals with chronic
respiratory problems, such as asthma, were quickly affected and accounted
for most of the hospital admissions.
8. It proved to be extremelv difficult to determine the size. shape. and
movement of the chlorine cloud.
Helicopter observation was a valuable asset, particularly with
increasing daylight. Ground sampling over large areas is difficult to
coordinate and requires careful mapping to be effective. An attempt was
made to predict dispersion of the chlorine using CAMEO (a computer
model program), but complicated factors of terrain, slope, temperature,
wind velocity, relative humidity, and an unknown rate of release made
predictions extremely difficult.
9. The application of water to the vapor cloud was considered in this
situation to accelerate the evaporation of the pooled liquid.
Conventional wisdom suggests that massive applications of water
spray could absorb chlorine from the air, resulting in a dilute liquid
solution. Chlorine has a low rate of solubility in water, and, with a large
leak, there is a concern that applying less-thansufficient volumes of water
would create a corrosive fog. Applying water to a container of liquified
chlorine could heat the contents to their boiling temperature and cause the
container to rupture. It is often difficult or impossible to estimate the flow
and rate of vaporization from a leak to make such determinations.
10. The delay in notification of the Fire Department and other agencies
indicates a problem with plant personnel and the established standard
operating procedures at the facility.
A review of communications tapes reveals that no call was received
by the Police or Fire Departments for this incident from the facility. A
private sector ambulance provider had been requested to respond to
transport plant employees who had been exposed to the chlorine gas.
11. While emergencv procedures had been planned for the chlorine
facility itself. there was no specific plan for notification or evacuation in the
event of a chlorine leak or other emergencv extending: beyond the propertv
line.
Due to the risk created by the chemical industries in the area, the
need for emergency warning systems should be evaluated. This level of
planning requires both private and public sector participation.
12. The fact that the incident occurred at the facility where the
CHLOREP Team equipment was stored caused unusual problems.
Most of the equipment that could have been most valuable in trying
to secure the leak could not be reached because it was in the hazardous
area. This included the SCBA units normally used by the team members,
which are of a different type from those used by area fire departments.
Another chemical plant in the area was able to provide the needed SCBAs
for the plant members on the entry team.
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