Saturday, 22 November 2008
Green Chemistry: Indian college laboratories to go green
November 22, 2008
By Syed Akbar
Hyderabad, Nov 21: Chemistry labs in colleges and universities will not smell foul or emit dense chemical fumes posing danger to the health of students, if the Department of Science and Technology has its way.
The DST has formulated a concept what it calls "Green Chemistry" to protect the health of students and teachers and keep the environment free of chemical pollutants. The DST's move comes in the wake of ban on smoking in public places.
A task force set up by the DST has prepared a set of guidelines for all educational institutions across the country as part of the Central government's efforts to make chemistry learning ecologically and health friendly.
The chemistry lab tests now conducted in most of the colleges and universities in the country were introduced more than 50 years ago.Many of these experiments, particularly involving toxic chemicals like liquid bromine, potassium cyanide, benzene, carbon tetrachloride, are not at all safe to human health.
The DST held a series of meetings including in Hyderabad before arriving at the new guidelines in the form of a monograph. It wants to reduce or eliminate the use and generation of substances hazardous to human health and environment, in educational institutions.
The Andhra Pradesh State government has expressed its willingness to introduce the Green Chemistry concept. "We are holding talks with universities and the Board of Intermediate Education. We are seized of the issue and take a decision on the implementation of new guidelines after taking into consideration the suggestions from our educational institutions," Prof KC Reddy, chairman of AP State Council of Higher Education, told this correspondent.
According to the new guidelines, wherever practicable, synthetic methodologies should be designed to use and generate substances that posses little or no toxicity to human health and the environment.
Chemical products should be designed to preserve efficacy of function while reducing toxicity. The use of auxiliary substances like solvents and separation agents should be made unnecessary wherever possible and, innocuous when used.
Under the new guidelines tests with mercury, arsenic, cadmium, lead, bismuth and chromium salts, which are toxic, will be excluded from syllabus meant for the undergraduate general stream students. But these tests may be kept for students of honours course for demonstration only.
College managements should avoid lab experiments using organic solvents like ether, petroleum ether or ethyl acetate. Instead they should use ethanol and methanol. Institutions should use alternative reagents which are not only eco-friendly but also be easily available anywhere in the country in bulk quantities at very cheap price.
The guidelines assume significance as the conditions in many laboratories for doing inorganic analysis by conventional methods in the undergraduate level are at all not eco-friendly. The gases are toxic and causes health-hazards. Insufficiency of exhaust fans remain a big problem. Sometimes experiments are carried out in closed doors in hot and humid conditions. Moreover, most of the labs not properly
Students often fall victim of this bad infrastructure. The acid fumes, which are toxic, pollute the atmosphere.
Some notable guidelines
1. Direct use of hydrogen sulphide (H2S) gas generated from Kipp’s
apparatus must be avoided.
2. A better alternative for hydrogen sulphide in inorganic group
analysis is highly desirable and efforts should continue to find one.
3. Rampant use of concentrated acids like nitric oxide (HNO3),
hydrochloric acid (HCl) must be avoided.
4. Ammonia bottles must always remain tightly corked. Chemical tests
using concentrated acids or ammonia must be carried out in fume-
cupboard. The gases from the exhaust may be passed through alkali
solution (preferably lime water) for absorption. The nitrite or nitrate
salts of calcium may be used as fertiliser.
5. Fire extinguisher, first aid kit, eye shower should be kept ready in a
particular common place. Hand gloves, safety glasses, and aprons must
be made compulsory during lab work.
6. Use of chemicals like carbon tetrachloride, benzene should be
avoided and can be substituted by toluene or acetic acid in butanol.
7. Experiments involving conductometry, polarimetry, potentiometry,
pH metry, colorometry, polarography, spectrophotomery, requires
chemicals in very low concentrations and have no negative influence
on the health or environment, hence these experiments may not need
any change or alterations.
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