In industry, “risk assessment” is the process of identifying, evaluating, and mitigating hazards. A grid similar to the one shown
below is typically used to estimate risks.
The impact of something going wrong (organized in columns)
is combined with the likelihood of it happening (in rows), and a
relative risk level is assigned accordingly. For example, if someone
is dissolving sodium chloride in boiling water using a stirring rod,
an accidental splash is somewhat likely. A boiling- water splash
will probably burn (recognized hazard), so this procedure comes
with a moderate risk.
Negligible Harmful Serious
L I K E L I H O O D Verylikely/ frequent Moderaterisk Highrisk Highrisk Somewhat likely Lowrisk Moderate risk Highrisk Unlikely Lowrisk Lowrisk Moderate risk
In the workplace, low-risk procedures are preferred. The aforementioned procedure could be made less risky by modifying it to
use a stir plate or room-temperature water, for example. Moder-ate-risk activities are considered carefully, with emergency plans
in place ahead of time. High-risk procedures are rarely, if ever,
approved because they do not meet legal or code requirements
without expensive engineering precautions.
3. What personal protective quipment do I need? This is probably the most complicated of the
safety questions. First, you must decide what personal protective
equipment (PPE) is required for the chemicals and the processes
you are using. Your specific PPE needs will depend on how the
work is being done.
Consider the following:
Fit. Take the time to find the right size protective equipment for
you. If your audience members will need PPE, be sure to have a
variety of sizes. Changing the brand may provide a fit.
Gloves. The width of your hand across your knuckles, in inches,
is your approximate glove size. Gloves should be tight enough to
move with you and keep out hazards, but they should not be so
tight that they tear easily or weaken the material.
Eyewear: Goggles should provide a complete, snug seal around
the eyes and the bridge of your nose. If they are too loose, hazardous liquids could splash in. If they are too tight, they may fog.
If you wear eyeglasses, look for goggles sold as “OTG” (over the
Lab coat. A lab coat should cover from your arms to your wrist and
fall past your knees. It should be just large enough to cover your
torso when fastened without gapping or restricting movement.
Loose sleeves can create a spill hazard; rolled-up sleeves can trap
chemicals. A lab coat that is too large can trip you, become caught
on equipment, or leave your neck area open for spills.
Type. Generally, if there is a possibility of a chemical splash of
more than 100 mL, then you need chemical splash goggles with
indirect venting. If you are using instrumentation or doing computer work in the lab, safety glasses may suffice.
Material. Chemicals can permeate all glove materials, eventually. The “permeation time” can help you decide which material is
best for your chemicals. If you cannot find a specific material for
your chemical, it may make sense to wear two pairs of gloves and
replace the outer gloves whenever they show signs of contamination or tears. Likewise, when working with flammable solvents
or demos that involve fire, you need a flame-resistant coat that
provides coverage to, at least, the knees. A rubber apron might be
needed if you are working with larger quantities of corrosive liquids.
4. What emergency response protocols will be needed if something goes wrong?
Chemistry laboratories will have spill kits, fire extinguishers, eye-washes, and safety showers available — but do you know how to
use them? An emergency is not the time to figure out how they
work, so ask your faculty advisor for a chance to try them before
you need them.