hazards

• Toxicity

  Some fuels, such as methanol, are toxic (harmful to your health).  Methylated spirit (used as a cleaning agent and a fuel) contains methanol and is toxic.
• Flammability

  Many fuels combust (burn) easily, so they should be kept in sealed containers when not being used and kept away from naked flames.
• Risk of explosion

  If a large amount of fuel vapour is exposed to a spark, there is likely to be an explosion.
• Carbon dioxide, along with various other compounds, prevents the earth’s heat from escaping into space and is resulting in an increase in the earth’s temperature. This is known as global warming. The result is the melting of the polar ice caps which is likely to cause severe flooding in the future, as well as serious damage to numerous ecosystems.

  Gases which contribute towards global warming are known as greenhouse gases.
• a)     water vapour

  Water vapour is also produced in large quantities as a result of combustion of hydrocarbons and is also a greenhouse gas.
• a)     carbon monoxide

  If oxygen is not present in sufficiently large quantities when a fuel is burnt, carbon monoxide or carbon is produced instead of carbon dioxide. Carbon monoxide is toxic.
•   carbon particles

  Incomplete combustion can also produce carbon particles, called particulates.  Carbon particles can damage the lungs and make it harder to breathe for asthma sufferers.
• sulphur dioxide

  Most crude oil deposits contain sulphur as an impurity so some sulphur is present in most hydrocarbon fuels. When the fuel is burned, the sulphur also burns, producing sulphur dioxide:

  S(s) + O2(g) à SO2(g)

  This gas dissolves in rainwater forming a very acidic solution of sulphuric acid (H2SO4), known as acid rain.

  SO2(g) + 0.5 O2(g) + H2O(l) à H2SO4

  This causes various problems, including erosion of buildings and statues, killing of plants and trees, and killing of fish through contamination of lakes.