Assessing Risk: Five Key Questions
for Safe Research and Demos
BY SAMUELLA SIGMANN AND RALPH STUART
After you have taken a couple of chemistry classes, it might seem that the safety rules you reviewed on the first day (“Wear your goggles”, “Use the hood when you need to”) told you everything you need to know about working safely with
When you start working with chemicals on your own —
whether in a research lab or in a chemistry demonstration
before an audience — the safety situation changes. In teaching
labs, someone has already identified the hazards and lowered
the risks as much as practical prior to your arrival. But research
work requires that you explore new ideas and deviate from
established experiments, which can introduce new hazards.
Meanwhile, chemistry demonstrations can take place outside the controlled environment of the lab, which can expose
both you and your audience members to a variety of new risks.
Both ethics and self-preservation require you to consciously
consider what unexpected results might arise in either situation (see The Chemical Professional’s Code of Conduct at
There are legal implications, too. Many states adhere to the
National Fire Protection Association’s recommendation that
educators conduct documented risk assessments prior to demonstrations or when students are using hazardous materials in
Learning to assess and address risk is vital to your academic
and professional career.
The following five questions will help you develop your risk
assessment skills and increase your understanding of chemical hazards. You should always document your answers to these questions
in writing so that you can explain them to others as the need arises.
1. What specific chemical or physical reactivity hazards are associated with the
way I’m using these chemicals?
Risk assessment starts with finding reliable information about
your chemicals (see Recommended Websites for Researching
Chemical Safety Data on page 8), but you should also consider
how you are using them. Sometimes simple substitutions of the
chemicals in a process or changing the amount or concentration
of the chemicals being used can create a different risk scenario.
Explosions at the University of Minnesota
and Texas Tech University are evidence of
the hazards associated with even small
changes in the chemistry being studied. 2, 3
Safety Data Sheets (SDSs) don’t always
provide specific information about these
changes because manufacturers of chemicals can’t predict all the ways researchers
will use them. Remember that the phrases
“Not Available” and “No Information” do
not mean “Safe.” Consulting information
resources beyond the SDS is important any
time you ( 1) change the chemical or process you’re using, ( 2) increase the concentration of the chemicals you’re using, or ( 3)
increase the quantities of the chemicals
you’re using by a factor of 3 or more.
For physical hazards associated with
chemicals, be particularly mindful of
chemicals that have a signal word “
Danger” with the Globally Harmonized System of Classification and
Labelling of Chemicals (GHS) icon of an exploding bomb, oxidizer,
or corrosive. For health hazards, be particularly mindful of the
skull and crossbones and health hazard icons. If chemicals with
these warnings are important to your experiment, be sure to
take protective measures, such as using only small quantities and
carefully controlling what the chemicals come into contact with.
2. What type of ventilation do I need? In the laboratory, both fume hoods and general
room ventilation rely on dilution to control the potentially hazardous vapors from chemicals. If there are likely to be significant
emissions of chemicals that you don’t want to breathe, you need
a fume hood. Remember that fume hoods have to be used correctly to contain vapors and are not meant to control fires, explosions, or particles. 4
So which chemicals don’t you want to breathe? For help in
making this determination, consult the SDS to identify toxicity
levels and odor thresholds of the chemicals. Look for the phrase
“well-ventilated space” in the SDS precautionary statements.
Seek advice from your advisor or chemical hygiene officer if
you do not know how the data you find apply to ventilation