More about the UVM mercury thermometer exchange program
In January 1997, Environmental Safety Facility technicians
became aware of a growing problem; an increase in the number
of broken mercury thermometer spills on campus. Not only was
this potentially dangerous, but cleaning up the debris is time
consuming, and the disposal costs are expensive. Highlighting
this increase in broken thermometers, the University had been
required by the EPA to have in place a chemical waste minimization
program. Since opening in January 1994 as a TSD (Treatment/Storage/Disposal)
facility, we had seen an increase in chemical waste due primarily
to our efforts at cleaning up old chemicals left over in chemistry
laboratories. Documenting that the University was actively engaged in
reducing the amount of chemical waste became one of the goals
of the ESF. Reducing the number of mercury thermometers on campus
became one way to show initiative in that direction. The vehicle
we chose for this project was UVM ChemSource, the chemical
and safety equipment distribution program for the campus administered
through the ESF.
Mercury as a Hazard
Mercury compounds have been used throughout history to chase
away evil spirits, change base metals into gold, and as medicine.
Of course, the usefulness of mercury is limited by it's poisonous
nature. As with most chemicals there are two types of mercury
poisoning--acute and chronic. Acute mercury poisoning results
from the ingestion of soluble mercury salts which corrode skin
and mucous membranes. Mercury vapor aspirated into the lungs
can cause severe pneumonia and death. Chronic mercury poisoning
occurs through the regular absorption of small amounts of mercury.
This condition is often a disease of workers in mercury mines,
laboratories, and industries that use mercury. Organic mercury
compounds, such as dimethyl mercury, are among the most dangerous.
Mercury vapors are colorless, odorless, tasteless, and toxic.
When mercury thermometers break, laboratory and clean-up personnel
are exposed to dangerous mercury fumes. An incomplete clean-up
creates the threat of long term exposure to mercury fumes. Furthermore,
drops of the liquid metal can become lodged in floor cracks
and behind equipment. Depending on the amount spilled and the
air movement within the laboratory, the mercury vapor concentration
in a laboratory with "hidden" mercury spills may exceed safe
limits. A spill is more dangerous when mercury thermometers
break in ovens or incubators because mercury evaporates readily
at high temperatures, creating high mercury concentrations.
Disposal of mercury thermometers and the contaminated clean-up
materials generated by a spill is very expensive. Materials
containing mercury are currently disposed of at a cost upward
to $100 per gallon. Thus, one 55-gallon drum of mercury waste
shipped for disposal, could potentially cost the University
$5,500. Spill debris uses much more space than an intact thermometer,
resulting in increased cost. Special clean-up procedures, such
as dismantling an incubator or oven that has spilled mercury
also increases costs substantially.
In the Beginning
Our initial search for replacement thermometers turned out
to be a less than easy task. Most suppliers and vendors had
very small selections of environmentally safe thermometers.
The most common being the red alcohol thermometer, which we
decided against mostly because the color did not meet our environmental
perceptions. Early on we investigated a green spirit filled
Enviro-Safe thermometer distributed by H-B Instrument Company.
After several in-house tests and trial uses on campus, problems
with column separation, thus accuracy, occurred, so we continued
our search. We previewed various thermometer catalogs, trying
to come up with a good selection of safe thermometers; our great
wish being to get a good price. We had decided that the initial
exchange would be funded through our operational budget. We
turned to one of our campus scientific vendors, Krackeler Scientific
http://ksionline.com to help
us in our search. Eventually we came upon a blue spirit Ever-Safe
thermometer distributed by Ever Ready Thermometer Company http://www.ertco.com
of West Paterson, New Jersey.
Learning of our project the Chemistry Department immediately
put in an order for replacement thermometers to be used by it's
undergraduate and graduate laboratories. We eventually stocked -20/110
deg. Celsius (both total and partial immersion),and -10/260
deg. C, partial immersion thermometers--both in 1.0 scale divisions,
as well as -1/101 deg. Celsius thermometers marked off in .2
scale divisions. Choosing between a partial or total immersion
thermometer created further problems.
Partial or Total Immersion?
Total immersion thermometers are designed to indicate temperatures
correctly when the bulb and the entire liquid column are exposed
to the temperature being measured. A partial immersion thermometer
usually has a line or mark at the immersion distance from the
bottom. It reads correctly when the bulb and the liquid column
to that line are exposed to the temperature being measured and
the emergent stem is at ambient or surrounding temperature.
Step By Step
We needed to create an effective way to publicize the "swap."
We hired a graphic artist to develop a flyer for us that would
grab the attention of laboratory faculty and staff--not always an easy
task. We spent a fair amount of time selecting an appropriate
logo and colors for this project, but eventually came up with
a design we liked. Fortunately we had already gone through some
of the details beforehand when UVM ChemSource first got
underway.
By the Spring of 1997 we were ready to introduced our "Mercury
Thermometer Swap." Surveys were sent to individuals and
departments that we felt would most likely have significant
numbers of mercury thermometers to exchange, one-for-one, and
cost free. We also included several articles announcing the
thermometer "swap" in Safety News, the University's
chemical safety and health newsletter. As envisioned the initial
cost would be covered by our operational budget, but we had
no idea how many thermometers actually existed on campus. From
the start we had expected a relatively small exchange, and were
slightly overwhelmed by the initial request from the Chemistry
Department for over 800 thermometers. By January 1999, we had
exchanged over 1,450 thermometers--with the bulk of them going
to the Chemistry Department, and the remaining thermometers
swapped or sold to other campus laboratories. Those investigators and
laboratories that didn't have mercury thermometers to exchange could
buy our non-mercury thermometers at greatly reduced cost. We
instituted a 90-day return policy during which we stored the
mercury thermometers at the facility until we received favorable,
or no feedback concerning the use of the new thermometers. After
that time we would declare the mercury as hazardous waste. We
later sent a customer survey to the "swap" participants
for their comments about the exchange in general. We eventually
filled one 55-gallon barrel with these thermometers at a disposal
cost of about $3,700.
More Precise, Sharing the Cost
We received several requests for specialized thermometer replacement,
and supplying these would cost far more than our budget could
handle. We were able to get a promise from the Chemistry Department
to help offset the increase in cost, with an agreement to share
those costs over the next two fiscal years. In particular, the
Chemistry Department's required thermometers marked off in .1
divisions. Upon placing an order with ERTCO, we were told that
these were no longer being made, and were being replaced with
.2 division thermometers. We had to verify how accurate these
thermometers would be for general laboratory purposes. We talked
directly with an ERTCO technical sales advisor and were sent
calibration certification results to review. The .2 division
thermometers performed well, with some decree experienced
at the higher end of the temperature scale.
Overview
In general our campus initiative to replace mercury thermometers
with more environmentally safe thermometers went well. This
"short term" project became more complex then we initially
thought. The program added yet another dimension toward meeting
our overall waste minimization objectives, while helping to
bring about an increased awareness of the dangers involved with
mercury. The campus has been given a non-mercury thermometer
alternative to replace those "unloved" mercury thermometers,
and has also helped reduce the University's overall clean-up
and disposal costs. It is a small but hopefully model program
for continued thermometer swaps, and waste minimization strategy.
Last Updated:
October 12, 2006
