Chemistry in Action

Health, Safety and the
Key Terms
 Green Chemistry
 The Atmosphere
 Acid Rain
 The Ozone Layer
 The Carbon Cycle
 Global Warming
 Ocean Acidification
 Risk Assessment
Principles of Green Chemistry
Prevent waste.
Minimise hazardous chemicals produced.
Design safer chemicals.
Be energy efficient.
Use renewable reactants.
Use catalysts.
Design degradable products.
Monitor and control release of hazardous materials.
Prevent accidents.
The Atmosphere
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
Acid Rain
 Used to be caused by
factories releasing SO2 and
NO but due to a concerted
effort by governments
working together it is no
longer an issue.
Thinning of the Ozone Layer
Thinning of the Ozone Layer
Thinning of the Ozone Layer
 Ozone (O3) 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
 This is also no longer a problem as governments around
the world again worked together to stop the use of
Other Things We Have Fixed
 Banning the use of pesticides that damage the
 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
The Carbon Cycle
The Carbon Cycle
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 + O2  CO2
 Burning methane for heat or cooking
 CH4 + O2  CO2 + 2H2O
 Burning octan in cars
 2C8H18 + 25O2  16CO2 + 18H2O
The Carbon Cycle
The Carbon Cycle
 The release of CO2 is also causing problems in our
oceans by forming carbonic acid (H2CO3)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
 ‘Carbon-Cycle-Full’ By Sahmed1890 (Own work) available at, via Wikimedia Commons
 ‘Edge of Space’ By NOAA & Ævar Arnfjörð Bjarmason (from
U.S. National Weather Service (NOAA) [1])
_Space.png, via Wikimedia Commons
Image Credits
 ‘Bleachedcoral’ Acropora at English Wikipedia available at
coral.jpg, via Wikimedia Commons