Health, Safety and the Environment

Key Terms  Green Chemistry  The Atmosphere  Acid Rain  The Ozone Layer  The Carbon Cycle  Global Warming  Ocean Acidification  MSDS  Risk Assessment

Principles of Green Chemistry 1.Prevent waste. 2.Minimise hazardous chemicals produced. 3.Design safer chemicals. 4.Be energy efficient. 5.Use renewable reactants. 6.Use catalysts. 7.Design degradable products. 8.Monitor and control release of hazardous materials. 9.Prevent accidents.

The Atmosphere

 Most of the atmosphere is nitrogen.  A tiny but significant amount is carbon dioxide (around 0.03%).

The Atmosphere  Highest skydive was 37km.  ISS is 330km above Earth.  Earth’s atmosphere is comparatively thinner than the skin on an apple.

Acid Rain

 Used to be caused by factories releasing SO 2 and NO but due to a concerted effort by governments working together it is no longer an issue.

Thinning of the Ozone Layer

 Ozone (O 3 ) exists in the upper atmosphere and protects us from UV rays.  Photochemical smog (eg NO) and CFCs bind to the oxygen atoms and prevent them from absorbing UV rays.  This is also no longer a problem as governments around the world again worked together to stop the use of CFCs.

Other Things We Have Fixed  Banning the use of pesticides that damage the environment.  Removal of lead from fuels and other heavy metals from paints and dyes.  Less use of solvent based enamel paints in favour of acrylic paints.  More consideration given to occupational health and safety.

The Carbon Cycle

 Burning fossil fuels leads to the release of carbon dioxide, which contributes to the Greenhouse Effect.  Burning coal in power plants  C + O 2  CO 2  Burning methane for heat or cooking  CH 4 + O 2  CO 2 + 2H 2 O  Burning octan in cars  2C 8 H O 2  16CO H 2 O

The Carbon Cycle

 The release of CO 2 is also causing problems in our oceans by forming carbonic acid (H 2 CO 3 )raising the acidity of the water.  This is very damaging to coral and phytoplankton.

Limiting Risk  Scientists use material safety data sheets (MSDSs) and risk assessments to limit the danger to themselves and the environment.  MSDSs list all of the safety information regarding chemicals including:  Physical and chemical properties  Effects it may have on the body  Safe handling procedures  First aid instructions  Disposal instructions

Risk Assessments  Weigh up all of the potential risks involved with a procedure including:  The dangers of the reactants, products and by-products to people as well as to the environment.  The risks of using any equipment involved in the procedure including glassware, electrical equipment etc.

Image Credits  ‘Composition of Earth’s Atmosphere en’ By User:Dbc334 (File:Composition of Earth's atmosphere.svg) available at tion_of_Earth%27s_atmosphere_en.svg, via Wikimedia Commons tion_of_Earth%27s_atmosphere_en.svg  ‘Carbon-Cycle-Full’ By Sahmed1890 (Own work) available at cycle-full.jpg, via Wikimedia Commons cycle-full.jpg  ‘Edge of Space’ By NOAA & Ævar Arnfjörð Bjarmason (from U.S. National Weather Service (NOAA) [1]) _Space.png, via Wikimedia Commons _Space.png

Image Credits  ‘Bleachedcoral’ Acropora at English Wikipedia available at coral.jpg, via Wikimedia Commons coral.jpg