Inherent Safer Design and its 4 Principles - Green Chemistry

The concept of Inherent Safer Design (ISD) states that hazardous should be avoided instead of controlling them. This can be done by reducing the amount of hazardous material and the number of hazardous operations in the industrial plant.

The statement "what you don't have cannot harm you" was given by a British chemical engineer Trevor Kletz in an article published in 1978 after the Flixborough disaster. This statement means that we should reduce the hazard instead of controlling them.

For example, If benzene is replaced by a green solvent then how can benzene affect us in the future (What you don't have cannot harm you).

There are four principles of inherently safer design:

1. Minimisation

This method of Inherent Safer Design states that we should use small quantities of hazardous materials or reduce the size of equipment operating under hazardous conditions like high temperature and pressure.

For example, Nitroglycerine can be manufactured in a continuous pipe reactor with a few kilograms of batch instead of a large batch reactor with several thousand kilograms of the batch.

2. Substitution

This method of Inherent Safer Design states that we should replace a hazardous chemical with the safest one. 

For example, toxic benzene should be replaced by a green solvent like supercritical carbon dioxide, water, etc.

3. Moderation

This method of Inherent Safer Design states that we should shift to less hazardous processes and chemicals and modify facilities to minimize the impact of hazardous chemicals released by manufacturing plants.

For example, Monomethylamine should be stored under refrigerated conditions which will significantly reduce the hazard to the surrounding community by reducing the amount of material transported into the atmosphere in case of a leak or blast.

4. Simplification

This method of Inherent Safer Design states that we should design facilities in such a way that it eliminates unnecessary complexity and reduce the chances of operating errors.

For example, Old and complex piping should be removed from the factory and new less complex piping should be done to ensure the smooth transfer of reagent throughout the factory.

Popular Posts

Conducting Polymers: Definition, Examples, Properties and Applications

Image
What are Conducting Polymers? As the name suggests organic polymers that conduct electricity are known as conducting polymers. They are also known as intrinsically conducting polymers (ICPs) and they have alternating single and double bonds along the polymer backbone (conjugated bonds) or that are composed of aromatic rings such as Phenylene, naphthalene, anthracene, pyrrole, and thiophene which are connected through carbon-carbon single bonds. Examples: Polyacetylene, Polypyrrole, Polyaniline, etc What is the reason behind conducting nature of these polymers? Conducting polymers comes in two forms that are doped conducting polymers and non-doped conducting polymers. The conductivity of non-doped conjugated polymers is due to the existence of a conductivity band similar to a metal. In a conjugated polymer, three of the four valence electrons form strong sigma bonds through sp² hybridization where electrons are strongly localized. The remaining unpaired electron of each carbon atom re
Read more

Crime Scene: Definition, Types and Characteristics

Image
What is a Crime Scene ? A place where the crime is committed or where the maximum physical evidence related to crime is found is known as a crime scene. A crime scene is a starting point of the investigation which provides information about the suspect and the victim. This helps to reconstruct the crime and fast resolution of the case. It is noted that the crime scene is not limited to a single place but may extend to a wider area depending upon the nature of the crime committed. For example, In a murder case where murder is done at one place and the body is disposed on another place. In this case, we have two crime scenes that give information about the crime. Types of Crime Scene Based on evidence found on the crime scene: 1. Primary Crime Scene The crime scene where the actual crime occurred or where more usable pieces of evidence were found is known as the primary crime scene. For example, A murder scene, theft, assault, etc. 2. Secondary Crime Scene The crime scene which is some
Read more

Documentation of the Crime Scene: Step by Step

Image
What is documentation of the crime scene and Why it is done? After securing the crime scene, the next most important step is documentation of the crime scene because documentation permanently records the crime scene and its physical evidence. Documentation should be done without any wastage of time as the scene and its evidence may get altered over time. The documentation should be done innovatively and the originality of the crime scene should be maintained and documentation should not have pauses or breaks, it should remain constant till the whole crime scene is documented. There are four main tasks of documentation that is note-making, photography, videography , and sketching . It should be noted that all four tasks are necessary and none is a substitute for another. For example, notes are not substitutes for photography, video is not a substitute for sketching, etc. Following are the sequence for crime scene documentation: 1. Note making Documentation of crime scene in the f
Read more