 In this video, we are going to consider the environmental impact caused by a range of different types of chemical industries. Chemicals produced by the chemical industry are used to make virtually every human made product we know and play an important role in our everyday lives. These products can protect our crops from pests and increase their yields. Other chemicals can prevent or cure diseases. Some might provide us with insulation to reduce energy use and offer countless other benefits. These chemicals are produced by different types of chemical industries and include basic chemicals, things like bulk petrochemicals and intermediates, other derivatives, synthetic rubbers, surfactants, dyes and pigments, resins and explosives. And inorganic chemicals, salt, chlorine, caustic soda, acids, titanium dioxide used as a whitener, hydrogen peroxide, a bleach and finally fertilisers. Then there's the speciality chemicals, things like electronic chemicals, industrial gases adhesive and sealants, coatings, industrial cleaning chemicals and catalysts. And then life science chemicals, these include the pharmaceutical and agrochemical industries. These industries produce biological substances, drugs and medicines, diagnostic chemicals, animal healthcare products, vitamins, pesticides, herbicides and fungicides. Finally, the consumer care product industries. These are where we get our soaps, detergents, bleaches, laundry aids, hair care products, skin care products, fragrances and fibres, nylon for example. As diverse as the chemical industries are, so are their environmental impacts. All of these industries use natural resources. The use of these resources could impact the environment in two ways. Firstly, chemical industries deplete our resources, especially renewable and non-renewable. And secondly, during their use, they can create pollution, especially during combustion. The chemical industries use a combination of natural gas, carbon and coke, minerals, water, fuel oil and electricity as a source of energy. Can you think how chemical industries might use water other than as a raw material? Pause the video and resume when you have an answer. The key use of water is as waste control, where the waste stream from chemical processes are treated with water to dissolve materials and in the heating and cooling of reactions. The impact of water use on the environment is not solely due to the volume of water consumed, but also the altered chemical composition or the temperature of the used water being returned to the environment. Obviously the discharge of polluted water is a concern, but the discharge of heated effluent or wastewater can also have a significant impact on aquatic ecosystems. The energy used to power these chemical industries come from oil, natural gas and coal. As a result, the chemical industries account for about 7% of the total world energy use and contribute up to 4% of all the world's CO2 emissions. Future trends in CO2 emissions, while obviously related to energy use, will also depend on the commitments made by governments and industry to fulfill goals set out in the Kyoto Protocol or its successor. If you're not sure what this is, you could look it up as it's a very important treaty in reducing environmental impact. A piece of good news is that substances which cause acid rain and the tropospheric ozone responsible for photochemical smogs are on the decline. In addition, chemicals like chlorofluorocarbons, CFCs, which were used as refrigerants, are also in decline. This is because of the recognised impact on forming holes in the stratospheric ozone layer. Alternatives to these, hydrochlorofluorocarbons have only 2-5% of the ozone-depleting potential of CFCs, but unfortunately have very high global warming potential. Next, let's consider the hazardous chemicals that chemical introduced produce or release. The number and volume of hazardous substances released during chemical production processes remain unknown. There is no one universal list of such substances. Different countries establish their own list of substances they consider to be hazardous, based on the data available to them. Thus, substances which may be hazardous, but which have not yet been categorised as such due to a lack of toxicity data are not listed. Finally, two countries, although using the same data, may not characterise the hazards of a particular chemical in the same way. In summary, there are a diverse range of chemical industries. These impact on the environment in a number of ways. The materials they use in their feedstocks, their energy requirements, the chemicals they produce, how these impact on the environment and ecosystems, and finally, how the industries manage their waste streams.