Session 2020-2021
Content Beyond Syllabus.
This Presentation include Principle No. 12 of Green Chemistry .I.e. Inherently Safer Chemistry For Accident Prevention.In this it include Introduction,Herarchy of security control,Herbicide, Reaction of herbicide formation and Case Study on Bhopal Disaster with Some Related News.
2. GREEN CHEMISTRY
– PRINCIPLE #12 : INHERENTLY SAFER CHEMISTRY FOR
ACCIDENT PREVENTION
– BY : JANVI TIKLE,KALYANI
ITANKAR,CHAITALI LONARE,DIVYA
JETHANI.
3. INTRODUCTION :
Substances and the form of a substance used in a chemical process should
be chosen to minimize the potential for chemical accidents ,including
releases ,explosions ,and fires.
– The Twelfth Principle of Green Chemistry is the Principle of Inherently Safer
Chemistry for Accident Prevention .The basic requirement is to reduce the use
of substances in chemical processes that can cause adverse effect (explosion ,
fire and harmful vapour). An example is today the increasing use of supercritical
CO2 that replaces organic solvents and which, unlike organic solvents ,is not
toxic or explosive and is environmentally acceptable.
4. HIERARCHY OF SECURITY CONTROL :
– Safety can be defined as a control of
known hazards by achieving an
acceptable level of risk and is
achieved at several levels of the
lowest use of Personal Protective
Equipment. Then it follows the level
of Administrative and Work Practice
Controls and implies establishing
effective procedures, rotating work
tasks, adjusting work schedules so
that workers are not over-exposed to
the impact of dangerous chemicals,
etc.
– The next higher level of security
control is the expert Engineering
Controls, which implies the
implementation of physical process
change to reduce contact with
hazardous chemicals, isolate the
process, use wet methods to reduce
dust formation, ventilation,
digestion, etc. The highest level of
safety control is achieved by
eliminating or replacing the
procedure with safer
alternatives(Figure 6).
5.
6. HERBICIDE
It is not in the interest of any industry to waste resources or
endangered its workforce, and this is as much an incentive to reduce
emissions as are the legal requirements placed upon manufacturers.
Some processes of necessity need the handling of dangerous materials
but wherever possible industry is attempting to make this safer. One
way is to alter the reagents used. For Example; One process used in the
manufacture of the most widely used herbicide , glyphosate (sold as
Roundup),uses the sodium salt of 2,2’-iminodiethanoic acid as one of
the intermediates. This is made in a series of reactions from ammonia,
methanol(formaldehyde) and hydrogen cyanide is a very useful reagent,
it is extremely toxic. A recent innovation has been the introduction of a
new route to the sodium salt. The starting materials are ammonia and
epoxyethane, which, on reacting ,from 2,2’-iminodiethanol, often
named diethanolamine. This is then converted to the sodium salt of
2,2’-iminodiethanoic acid .
8. CASE STUDY ON BHOPAL DISASTER :
– A Hazardous Chemical that can be
replaced in synthesis is METHYL
ISOCYANATE, a molecule used in
synthesis of the insecticide CARBARYL. In
1984, this toxic compound was released
into the air from a pesticide plant in
Bhopal, India, immediately killing 3,800
people, and causing premature death in
thousands more. This disaster could be
avoided had the plant instead used the
METHYLAMINE to carry out the reaction.
9. SOME RELATED NEWS :
– The health and safety of workers are under the preview of the Occupational Safety and Health
Administration (OSHA). In a recent news release, OSHA unveiled a chemical management
system designed to increase workers safety. The Hierarchy of Safety Controls as highlighted in
OSHA’s new Transitioning to Safer Chemicals Toolkit illustrates the difference between
focusing on the control or hazard part of the safety definition. Traditional chemical safety
models focus primarily on the control component of that definition. The graphic (adapted
from OSHA) shows that the most effective means of increasing safety is eliminating the hazard
component. Since the elimination of hazards is the basic tenet of Green Chemistry , this
marriage of the ideas of Green Chemistry from both OSHA and EPA(Environmental Protection
Agency) should have a synergistic impact on hazard reduction. Combining the forces of these
two agencies toward a common goal may lead to conversations and changes that result in
safer conditions for workers , a safer environment for the general public , and a safer planet
for us all.
