NC State Chemistry Department Safety Moment about Spreading Liquid Bacteria Cultures on Agar-Media Plates

1. Reducing Fire Risks
in Sterilization Procedures

2. While plating bacteria onto a petri dish using ethanol
and a Bunsen burner, a researcher’s bare arms and
t-shirt caught fire as a result of spilling the ethanol.
Flames were reported to be up to 0.6 m high. Other
combustibles caught fire, as well.
The researcher put out the flames on himself and
cooled his burns using the safety shower. A colleague
put out the other combustibles with a fire
extinguisher.
The researcher was transported to the hospital and
treated for 1st and 2nd degree burns.
from “Lesson Learned - Ethanol Fire Burns Researcher”
http://www.ehs.berkeley.edu/lessons-learned/lesson-learned-ethanol-fire-burns-researcher
Photo of lab bench with
burned ice bucket and
burned chair

3. Consider alternate
sterilization procedures.
Keep stock bottle and dipping container
≥ 30cm from burner.
Slowly turn spreader in flame to prevent
burning drops from falling.
≥ 30 cm
EtOH
Shielded
Electric
Incinerator
Glass
Beads
Disposable
Spreaders

4. Recap EtOH stock bottle and
dipping container btwn uses.
Use a capped stock
bottle w/ a lower
center of gravity.
Use only the minimum
needed in dipping container.
≤ 10mL of EtOH

5. Keep safety shower
and path to it clear of materials. Eyewash
Safety
Shower
Min Dist’s Required of Clear Space
Around Safety Showers
48”
30”
Navy Blue
fire resistant
Royal Blue, Nomex
MAX flame resistance
Wear flame resistant
or retardant lab coat.

6. SOP for Spreading Bacteria Cultures