Vacuum Flask Incident
A
researcher at the University of Delaware was performing
tissue culture work. They had a vacuum flask set up to aspirate the cell
culture media off the samples. This consisted of a 4 liter flask with
tubing and
a pump for the suction. The flask and pump were sitting on the floor
below the biosafety cabinet. The flask contained a small quantity of cell
culture waste and sodium hydroxide pellets had just been added to inhibit
bacterial growth. Cotton from a pipette became lodged in the vacuum
tubing. The researcher was advised to aspirate liquid through the system
to dislodge the cotton. Water was aspirated in hopes of clearing the
clog. Instead, the flask exploded sending shards of glass and liquid
throughout the room. No one was cut by the flying glass, but the
researcher was splashed with the concentrated sodium hydroxide. The
researcher had been wearing a lab coat and safety glasses as required, but
received a splash to the forehead just above the glasses. The researcher
immediately removed the contaminated safety equipment and flushed their
face in the eyewash. Public Safety and Environmental Health & Safety
were notified by a second researcher in the room at the time.
Upon investigation, it was determined that the water reacted with the
sodium hydroxide causing an exothermic, or heat-producing, reaction. The
flask being used was a standard flask; it was not designed to be used as a
vacuum flask.
Lessons to be learned:
- Safety glasses do protect your eyes from hazardous material
accidents that occur when you least expect them.
- Use a flask designated as a vacuum flask. These are heavier glass and
are less likely to shatter.
- Wrap a
vacuum flask in tape or place it in a plastic secondary
container to minimize the hazard of flying glass in case the flask
breaks.
- Include a
pressure-relief valve in the design of your vacuum system to
minimize the risk of pressure building too high.
- Use a
disinfectant with a low hazard level. Bleach is effective for
most tissue culture work. Always check the compatibility of the
disinfectant
with any other materials being added to the system and verify its
effectiveness against any biological materials.
- Never
work alone with hazardous materials. This researcher was
fortunate to have someone with them to call for help as they washed in the
eyewash.