http://www.geniescientific.com/fume-hoods-what-are-they-and-why-are-they-so-important-to-lab-safety/ | What are fume hoods and why are they so important for lab safety? Learn the answer to these questions in this informative presentation.

1. Fume Hoods: What Are They and Why
Are They So Important to Lab Safety?

2. In December of 2008, a staff researcher named Sheri Sangji was
working in a UCLA chemistry lab when a terrible accident occurred.
As she was transferring a substance known as tert-butyl lithium,
the syringe carrying the chemical broke apart, releasing flammable
material onto her clothes and skin. As soon as the tert-butyl
lithium came into contact with the surrounding oxygen, it ignited,
burning over 40 percent of Sangji’s body. Less than three weeks
later, she succumbed to second and third-degree burns and died in
the hospital.
A number of such tragic accidents have occurred over the years in
research labs across the world. Unfortunately, the death of Sheri
Sangji is only one of many cases that highlight the need for proper
lab planning, safety procedures, and lab furniture. To stress the
importance of worker safety, we’re starting with the basics. What is
a fume hood and why is it the first line of defense in any
laboratory?

3. What Exactly Is a Fume Hood and What Does It Do?
A fume hood or exhaust hood is a critical piece of laboratory
equipment that allows personnel to conduct potentially hazardous
work in a partially enclosed space. Chemical hoods serve a number
of critical functions, including:
Protecting laboratory personnel from the effects of toxic fumes by
exhausting vapors away from the lab workbench or work area
Ensuring proper ventilation of the entire laboratory area by
circulating air, particularly drawing in and removing contaminated
air
Shielding researchers from the devastating effects of chemical
spills, fires, and unintended reactions

4. Why Are Chemical Hoods So Important?
A fume hood is arguably the single most important piece of
equipment in any laboratory environment. That’s because it is the
first line of defense against many of the top laboratory dangers,
which include:
Inhalation of harmful vapors
Fires or explosions
Chemical or thermal burns
Chemical absorption
Toxic Chemicals
Topping that list of perils is the inhalation of toxic fumes. When lab
workers breathe harmful particles into their bodies, the toxins not
only lodge in parts of their lungs, but can also enter the bloodstream
and lead to negative reactions.2 Proper ventilation of the work area
and the laboratory environment are, therefore, critical to ensuring the
well-being of personnel

5. Recognizing the Limits of Fume Hoods
Although fume hoods are essential, they do not protect against every
hazard. Biological work involving potentially dangerous micro-
organisms, for example, requires separate biological safety hoods that
are designed specifically to deal with organic threats. Work that
involves radiological materials or perchloric acid also requires
separately designed hoods—a Genie Radioisotope Fume Hood and a
Genie Perchloric Acid Fume Hood, respectively.
Furthermore, while properly used fume hoods can shield employees
from certain types of volatile reactions, they are not designed to
handle every explosion. It’s, therefore, important to recognize the
limits of each piece of equipment and to purchase the right unit for
the particular task at hand. Expecting each fume hood to protect
against every laboratory danger is the surest way to lull workers into a
false sense of security.
In spite of these caveats, chemical hoods are indispensable to the
overall safety and integrity of laboratories. There are countless perils
that come with lab work, but a properly manufactured and installed
fume hood can mitigate many of those risks.

6. A fume hood has a number of interrelated parts that work together to
provide shelter and ventilation to lab workers, namely:
The hood body
The sash
The exhaust duct
The baffles
The airfoil
The two main components are the body of the hood and the sash.
The hood itself contains a work surface, enclosed completely on three
sides, on which lab personnel can conduct their research. The sash
comprises the last section and acts like a window or panel. A worker
can open it to gain access to the hood or close it to restrict airflow.
The baffles, typically located at the back of the unit, are basically
slotted panels that draw air into and toward the back of the unit. Lab
workers or managers can adjust these baffles to modify the air flow
into the hood. Finally, the exhaust duct releases contaminated air to
the outside.
What Are the Basics of Fume Hood Construction?

7. How Does a Properly Manufactured Fume Hood Work?
A fume hood ventilates the laboratory by drawing polluted air into the
unit and away from the lab worker, then up the exhaust and out of the
room, all the while diluting contaminated air by mixing in fresh air. This
process requires a sufficient quantity of air in order to proceed
according to design. Installing too many hoods in too small a space
may, therefore, compromise effectiveness unless a separate air source
pumps additional ventilation into the laboratory.
Additional Tips to Maximize Efficiency
Although Sheri Sangji was using a laboratory fume hood when her fatal
accident occurred, some reports suggest she might not have been
using it properly, or that the unit itself was not up to established safety
standards. Since investigators were unable to examine the unit as it
was at the time of the accident, there is no way to know whether the
severity of the accident was due to user or equipment error (or a
combination of both).

8. Whether improper fume hood safety was partly to blame in Sangji’s
case, it is invariably true that chemical hoods can only provide the
proper protection if lab managers install them correctly and lab
workers use them properly. To ensure lab safety, there are a few
considerations that every administrator should take into account
when installing and maintaining a fume hood:
• Hood Construction – There are basic safety standards governing the
construction of lab hoods, which is why Genie Scientific manufactures all of
its chemical hoods in the United States to meet or exceed industry
benchmarks (each unit must pass the ASHRAE 110 test and remain UL
Listed).
• Lab Planning – The layout of the laboratory itself, including the placement
of the hood, must take safety considerations into account. For example, lab
designers must never place a unit near doors or any other emergency exits,
and they must always account for foot traffic.
• Maintenance – Lab managers must maintain strict maintenance and
testing schedules, such as regularly replacing filters, to ensure the unit
stays in working order.
• Proper Usage – Managers should train all employees in proper equipment
and safety practices. Ensuring that all personnel follows OSHA’s guidelines
is a good start, although experts recommend enacting safety measures that
go above and beyond the minimum standards.

9. Are There Different Types of Fume Hoods?
Chemical hoods come in a wide variety of types and sizes. In addition
to special purpose units designed for radiological or perchloric acid
work, there are a number of other models, including the:
Bench-top fume hood
Walk-in fume hood
Double-faced fume hood
Workstation fume hood
Portable fume hood
Of course, some laboratories require specially constructed units to
accommodate particular needs. From extra deep, tall, or wide models
to enormous walk-in fume hoods, custom-built cabinets can handle
nearly any exceptional situation. Genie Scientific can also manufacture
chemical hoods with custom distillation or ventilation features.
Whatever the circumstances, it’s important to work closely with the
manufacturer to construct the right fume hood for the job at hand.

10. Three Decades of High-Quality Fume Hood Construction
Safety is the number one issue for lab planners, managers, and
workers alike. It’s also the most important factor driving Genie
Scientific’s quest for perfection. For over thirty years, we have
been manufacturing only the highest quality equipment for
laboratories around the country.
As a one-stop shop, we’re not only able to ensure the quality of
each and every unit, but we also take pride in our ability to work
closely with our clients to provide customized fume hoods for any
industry or application. Visit our site to learn more about our
dedication to laboratory safety.

11. Sources
Chemical and Engineering News. “Learning from UCLA: Details of the
experiment that led to a researcher’s death prompt evaluations of
academic safety practices.”
http://cen.acs.org/articles/87/i31/Learning-UCLA.html; Real Clear
Science. “Burning Negligence.”
http://www.realclearscience.com/lists/worst_lab_accidents_in_histor
y/burning_negligence.html?state=stop
University of Wollongong: School of Chemistry. “Use of the
Laboratory Fume Hood.”
https://smah.uow.edu.au/content/groups/public/@web/@sci/@chem
/documents/doc/uow059174.pdf
Ibid.
Visit our site to learn more about our dedication to laboratory safety.