What is Risk? Risk depends upon 2 factors: Chance of something happening Level of harm that occurs if it does
Risk Actual Risk – A Risk calculated from actual data Perceived Risk – A risk thought by individuals without clear data to support it
Precautionary Principle If the risks or harm from an activity may be greater than any benefit, it makes sense to restrict or stop the activity. This is particularly true where the level of risk is as yet unknown.
Salt and Health Risks: High Blood Pressure, Heart Disease and Strokes High Salt diet – Processed food with added salt Salt is needed – but no more than about 4g per day Current average intake in the UK: Men - 11g of salt per day Women - 8g of salt per day
What is an Alkali? Chemical Compounds that contain HYDROXIDE ions (OH-) Turn Universal Indicator Blue or Purple Have a pH over 7, usually between 9 (weak) and 14 (very strong)
Risks of Chlorine in Drinking Water Chlorine in drinking water can pose potential risks – creating chemicals which are toxic or even carcinogenic SO WHY ADD CHLORINE??? Benefit outweighs the risk
Questions Why is it important that drinking water is treated with Chlorine? Chlorine is a Toxic gas. How can it be safe to add it to drinking water? What potential health risks come from Chlorine in drinking water? Why do we continue to add Chlorine, despite the risks is poses?
Electrolysis of Brine Brine – Solution of Salt Water Salt – Sodium Chloride Electrolysis – Splitting up compounds using Electrical Current
Chemical Warning Signs Chemistry and Chemicals have their own warning signs of potential hazards These help you to take the correct precautions to ensure that you stay safe and risk is minimised. What do these hazard symbols stand for?
Assessing Chemical Risk We need to know: -How much of it is needed to cause harm -How much will be used -How it will be used -Chance of escaping into the environment -Who or what it may affect
Chemical Safety REACH Regulation Evaluation Authorisation and restriction of Chemical Substances
Risks of Plasticisers uPVC – Stiff, Tough Plastic used to make many things including Drainpipes, Doors and Window Frames PVC – Can be softened by adding PLASTICISERS. These make the plastic softer and more flexible. Used in sheeting, coating for wires and as a leather replacement.
Life Cycle Assessment CRADLE: What is your product? What materials is it made from? What raw materials are used? Are they sustainable? LIFE: What is your product used for? How long will it last? Is any energy or chemicals used in maintaining it during its life? How long is its life likely to be? GRAVE: What could happen to it at the end of its life? List all the alternatives and what would happen to it in this stage. Which of these is the best option and why?