[BNC-all] Incident Saturday evening, 28 July 2007, building now back to normal

[John Weaver]

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
<http://en.wikipedia.org/wiki/Sulfur> -containing chemicals (methyl
<http://en.wikipedia.org/wiki/Methyl>  and butyl
<http://en.wikipedia.org/wiki/Butyl>  thiols
<http://en.wikipedia.org/wiki/Thiol> ) that has a highly offensive smell
that can be described as a combination of the odors of rotten eggs
<http://en.wikipedia.org/wiki/Egg_%28food%29> , garlic
<http://en.wikipedia.org/wiki/Garlic>  and burnt rubber
<http://en.wikipedia.org/wiki/Rubber> . The odor of the fluid is strong
enough to ward off bears <http://en.wikipedia.org/wiki/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

Birck Nanotechnology Center

Purdue University

(765) 494-5494

jrweaver at purdue.edu

 

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