 When we wash our clothes, we use detergents. These remove the grime, sweat and stains that we pick up in everyday usage. However, but what cost? Each time you use detergents, there is an environmental impact. First, what chemicals or substances make up a soap powder or a liquid? Do you know any? Pause the video and resume when ready. The chemicals used to achieve stain removal and whiter-than-white clothes are a complex mixture containing surfactants which allow the water and the greasy stains to mix, making stains removable. Soap powders or liquids are often basic to help disrupt chemical bonds, neutralising acids and so make the surfactants job easier. There are also enzymes, biological agents which break apart fats, proteins and starch found in food stains, fragrance chemicals are added to give your clothes that fresh smell whilst bleaches containing peroxide or fluorescent whiteners give your clothes a renewed brightness. Yet, before the detergent makes it to a washing machine, it has to be manufactured and that's where the environmental concerns lie. You may have heard the idea of carbon footprints. If not, then check out the video on this channel. It's estimated that for every mile an average car travels half a kilogram of carbon dioxide is emitted. In America, families on average do 300 loads of laundry per year. This means that the carbon footprint of laundry detergents for one year of laundry is approximately 218 kilograms per year. While this seems low, this only factors in the detergent's use and not the energy usage of the washing machine or drying appliances. When you consider all of the families across the globe that use detergents the carbon dioxide footprint is considerable. Secondly, the chemicals found in washing detergents cause problems if they end up in rivers or streams. Can you think what the issue might be? Pause the video and when you have an idea, resume. An answer is that the chemicals found in detergents are toxic to aquatic organisms. One such chemical is phosphate found in many washing powders and this causes eutrophication. This is when an increased amount of phosphate leads to greater numbers of plant and algal material building up in rivers or lakes. The problems start once the plants die. The bacteria that feed off the decaying plant and algal material uses the oxygen dissolved in the water. The reduction in the amount of dissolved oxygen leads to changes in the types of species in the lake. For example, commercially and recreationally desirable fish such as trout are replaced by undesirable fish such as carp because they have a higher tolerance to lower dissolved oxygen levels or can result in no fish at all. Due to these environmental concerns eco-conscious consumers have called for the development of green detergents. It's now possible to buy detergents that do not contain perfumes or dyes and they're typically phosphate free and biodegradable. In addition, they're designed to work in cold water. Can you think why? Pause the video and resume when you have an answer. The answer is that using a washing machine on a cold setting prevents electricity being used to heat the water and so minimizes the carbon footprint for each wash cycle. Other environmental approaches also include using concentrated formulas. This is so less packaging is used in the manufacturer of the soapboxes or cartons and also reduces shipping and or trucking costs to move the shipment. As a result, this uses less oil.