Introduction to green chemistry

Why should anyone know about green chemistry? 
Our world population is expanding exponentially at an unprecedented rate, and as a result the amount of resources we require is much more than what the Earth's natural resources can sustain us for. For example, UK's reserves of oil, coal and gas is expected to run out in a little more than 5 years (http://www.bbc.com/news/science-environment-27435624). Therefore, in order to sustain our growth, we need to experiment and come up with ways which we can harness forms of energy to convert them into useful products. Green chemistry also reduces waste produced in the manufacturing process.
- legislation
- local authority and neighbourhood pressures
- waste disposal
- hazard evaluation
- health and safety
- increasing supply chain pressures
- inefficient use of raw materials

What is green chemistry? 
It is the design of chemical processes and products that eliminate or reduces the the use of and/or generation of hazardous substances.
- sustainable chemistry
- chemistry that is benign by design
- pollution prevention at molecular level

12 principles of green chemistry

1. Prevention - better to prevent waste rather than clean up after it has been produced 
2. Atom economy - a measure of amount of starting materials that go into the final product. % of atom economy = mass of desired product / total mass of reactants x 100% --> high or low atom economy. The higher the atom economy, means more atoms/molecules of reactants incorporated into product, greener product produced. NOT the same as percentage yield (gives no indication of waste produced)! 
3. Safer chemical synthesis and design - synthetic methodologies to use and generate substances that possess little or no toxicity to human health and environment. Chemical products to preserve efficacy of function while reducing toxicity. E.g. BPA in water bottles linked to health complications 
4. Safer solvents and auxiliaries - to be made unnecessary whenever possible and innocuous if needed
5. Design for energy efficiency - renewable energy and conservation of energy. Creating products in highly efficient manner while reducing energy requirements 
6. Use of renewable feedstocks - 90-95% of products we use in our daily lives are made from petroleum. Seeks to shift our reliance on petroleum to renewable materials that can be gathered/harvested locally. E.g. biodiesel. BUT there is the debate regarding if it is ethical to use food to synthesise products, taking into consideration that there are people all over the world with insufficient food. 
7. Catalysis 
8. Design for degradation -  degrade into safe, innocuous by-products when disposed of 
9. Reduce derivatives 
10. Real time analysis for pollution prevention 
11. Inherently safer chemistry for accident prevention