An evacuation of BNC occurred on Saturday evening, 28 July
2007, due to a strong odor in the cleanroom and remainder of the building. It
was determined that this odor was not caused by an event internal to the
facility and that it provided no hazard to occupants. The building
reopened, and has been in normal operation since early Sunday morning. The
details of the incident follow:
On Saturday evening, 28 July 2007, a graduate student in the
cleanroom smelled an overpowering odor that was thought to be a gas release. Not
knowing the nature of the gas, he made the very appropriate decision to exit
the cleanroom and sound the evacuation alarm. In the absence of more
information, this was the right decision to ensure the safety of all those
present in the facility. The building was closed at that point, and doors
were secured.
On exiting the building, the smell was significantly
stronger west of the building that it was inside the building. During the
response to the emergency it was determined that the smell in the building was
caused by one or more skunks (possibly two skunks fighting) upwind of the
building. The odors from the release by the skunks appears to have
entered the makeup air units and spread through the building. This odor
dissipated over time and the building was deemed safe by both BNC staff and the
Purdue University Fire Department and was reoccupied.
For those unfamiliar with skunks, the following quote from
Wikipedia describes the discharge: “(Skunks) produce a mixture of sulfur-containing
chemicals (methyl
and butyl thiols) that has a
highly offensive smell that can be described as a combination of the odors of
rotten eggs,
garlic and burnt
rubber. The odor
of the fluid is strong enough to ward off bears and other
potential attackers, and can be difficult to remove from clothing. Muscles
located next to the scent glands allow them to spray with high accuracy as far
as 2 to 3 metres (7 to 10 ft). The smell aside, the spray can cause irritation
and even temporary blindness, and is sufficiently powerful to be detected by
even an insensitive human nose anywhere up to a mile downwind.” It is certainly understandable that
this odor could be thought to be caused by a hazardous material, and the
evacuation was justified to ensure the safety of all personnel.
There were also reports of a haze/fog in the building by
some people, but others reported that they saw no haze, just smelled the
offensive smell. The cause of this haze has not been determined, and action
is being taken to determine if this was caused by lighting conditions.
The gas monitors – toxic, flammable, and refrigerant –
registered no elevated levels, other than the NO2 sensor which would
register the thiol levels from the skunk(s). As a safety precaution, all
NO2 was shut off at the cabinet, and the levels continued to
increase to a stable point for an extended period of time. This indicated
that the reading was indeed caused by something other than the gases in the
building. Additionally, levels of all gases were checked and none showed
a drop in volume as would have occurred had it been a gas leak.
The building was re-opened at approximately 1:00 AM on
Sunday. Because of the time of night, notifications of building closure
and reopening were not sent out. Due to some confusion on Sunday morning,
an e-mail to BNC-All was sent out assuring occupants that the building was
open. This communication procedure is being reviewed by BNC leadership to
determine whether notification should be initiated in this type of situation.
A special thanks is extended to all those who responded to
the emergency and ensured the safe reentry of the facility.
John Weaver
John R. Weaver
Facility Manager
(765) 494-5494
jrweaver@purdue.edu