Student
project identifies ways to reduce MIT’s hazardous chemical
wastes
By
Nancy Stauffer, MIT Laboratory
for Energy and the Environment
An
MIT researcher goes online to order a chemical for an experiment and
is greeted by a pop-up menu suggesting a less-hazardous alternative
that can do the job. From a linked website the researcher learns of
on-campus labs that need to order the same chemical or already have
extra supplies of it.
Outside of the lab, lectures and seminars repeatedly stress the importance
of minimizing the use of hazardous materials and developing products
and processes that minimize toxicity.
According
to a yearlong study by a student research team, such measures could
dramatically reduce MIT’s hazardous waste stream and the half-million-dollar
annual cost of dealing with it. More important, graduates of MIT would
understand and value the practice of “green chemistry,”
an approach designed to reduce or eliminate the use and generation of
hazardous wastes.
The
study, performed by Anneloes Hesen, Kendra Bussey, and Jacqueline Tio
under the supervision of Professor Jeffrey I. Steinfeld, focused on
the Department of Chemistry. In 2001, that department generated almost
half of MIT’s hazardous chemical waste, most of it from research
laboratories. The goal of the study was simple: to reduce the amount
of hazardous chemical waste generated.
“The
risk of a chemical is a function of its hazard and people’s exposure
to it,” said Ms. Bussey. “Traditionally, the focus has been
on reducing exposure to chemicals. But if you focus on minimizing the
hazard itself, you can reduce or eliminate the need to reduce exposure.”
In
their study, the students looked for opportunities to eliminate unnecessary
sources of hazardous waste and to introduce safer, less-toxic chemicals
for lab use. They first developed a list of chemicals that contribute
to hazardous waste. By analyzing inventory and purchasing reports, they
determined how much of those chemicals Department of Chemistry researchers
had bought during fiscal 2002–2003. They then searched the literature
to identify alternatives that are effective but less toxic and safer.
Finally, they interviewed personnel at 12 departmental laboratories
to find out what they used the selected chemicals for, their procedures
for ordering and disposing of them, and other details.
They
came up with a list of 15 chemicals of concern along with suggestions
for either replacing or reducing them. For example, benzene is purchased
in small quantities for use as a reaction solvent. But benzene is a
known carcinogen. In some cases, less-hazardous substances such as supercritical
carbon dioxide or even water could be used instead.
Also
on the list is acetone, a chemical purchased in large quantities. While
acetone itself is relatively benign, if it contains even a drop of a
toxic chemical, the entire volume must be treated as hazardous waste.
Acetone is used mainly for cleaning and rinsing glassware—a practice
that could be changed.
“We
can reduce almost 6,000 liters of waste each year just in the Chemistry
Department by oven-drying glassware instead of rinsing it with acetone,”
said Ms. Bussey. “You wash it in water and then put it in the
oven. [That approach] requires a little more planning, but it saves
a huge amount of waste.”
The
interviews showed several barriers to change. Researchers typically
have limited knowledge of alternative chemicals and solvents, and—given
the pressure to produce results at MIT—they are generally reluctant
to spend time and resources searching for less-toxic chemicals and processes
that would reduce waste. Also, many labs maintain inventories of excess
hazardous materials that often are eventually discarded; yet sharing
among labs is not a common practice.
To
ease those barriers, the students suggest enhancing MIT’s purchasing
system to provide buyers with information about less-hazardous options
and to match up buyers who need less than the minimum purchase of the
same hazardous chemical. They also recommend developing a formal online
chemical-exchange website and using shared chemical stockrooms.
But
the most important step is to educate the MIT community. According to
Ms. Hesen, many of the students interviewed “did not really think
about using [less-toxic alternatives] in part because it’s not
part of their education.” Green chemistry concepts should be incorporated
into introductory chemistry subjects and other classes and seminars,
and they should be put into practice in teaching labs.
“Many
of the future leaders in chemistry get their degrees from MIT,”
said Ms. Tio. “What they learn here they take with them, whether
it’s to another academic institution, industry, or even another
nation. But being a good leader requires an awareness of the other part
of chemistry—waste generation.”
Ultimately,
the students’ vision calls for changing the prevailing attitude
at MIT. Instead of being viewed as an unnecessary use of time and resources,
the discovery or development of sustainable options and substitutes
should become an integral part of the research process in all departments
and labs.
Jeffrey
I. Steinfeld is a professor in the Department of Chemistry and director
of the Education Program of the Laboratory for Energy and the Environment.
Anneloes Hesen received her Ph.D. from MIT’s Technology and Policy
Program in the Engineering Systems Division in June 2004. Kendra Bussey
and Jacqueline Tio are undergraduates in the Department of Chemistry.
This research was supported by the Paul M. Cook Innovation Fund with
matching funds from MIT’s Environmental Programs Office. The project
supports the consent decree between the US Environmental Protection
Agency and MIT that was approved in June 2001, following an inspection
in May 1998. Among the stipulations of the decree, MIT agreed to “set
up an internal program for preventing, reducing, recycling, reusing,
and minimizing waste and emissions, including procedures to encourage
material substitutions.” Publications are forthcoming.
(Note:
This article was originally published in the Decmeber 2004 issue of
energy &
environment, the newsletter of the MIT
Laboratory for Energy and the Environment.)
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