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Solvents & their impact on environment
- 1. SOLVENTS & THEIR IMPACT ON ENVIRONMENT BY:- WISHAL BUTT
- 2. SOLVENTS • A solvent is a substance that dissolves a solute resulting in a solution. • most of the solvents are combustible, often highly volatile and extremely flammable and they should always be handled with care.
- 3. INTRODUCTION • Every product we use have some impact on the environment. • The air that we breathe, the water we drink and the food we eat all contain naturally occurring chemicals. • For example, the smell of the forest is due to a mixture of certain organic chemicals. Many of these chemicals are classified as volatile organic compounds or VOCs.
- 5. OXYGENATED SOLVENTS • An organic solvent containing oxygen as part of the molecular structure. • EXAMPLE:- • alcohols, glycol ethers, ketones, esters, and glycol ether. • USES • These solvents are widely used in paints, inks, pharmaceuticals, perfumes, adhesives, cosmetics, detergents, and food processing.
- 6. DISADVANTAGES • During the synthesis of such solvents like alcohol, the residue of molasses is disposed off out of the industry containing microbes, may contaminate the soil & water. • Alcohol poisoning • Respiratory depressions • Low rate of metabolism by abnormal liver.
- 7. METHANOL • Methanol is the simplest alcohol and is a light, volatile, colourless, flammable liquid with a distinctive odour very similar to that of ethanol. • it is a highly toxic colourless liquid that may explode when exposed to flames
- 8. sources • Methanol can be produced from natural gas, coal and renewable sources such as municipal waste, biomass and recycled carbon dioxide. • Methanol – CH3OH – is four parts hydrogen, one part oxygen and one part carbon.
- 9. uses • antifreeze products • an ingredient of some paint • used in the production of some pharmaceuticals such as vitamins and hormones. • used in semi-conductor manufacturing.
- 10. DISADVANTAGES • swallowing, breathing or absorbing large quantities of methanol through the skin, as in an industrial setting, can cause death. • Exposure to methanol can cause visual problems and lead to blindness. • it can cause convulsions, coma, loss of consciousness, kidney failure, liver damage, low blood pressure, respiratory arrest and damage to the central nervous system.
- 11. HYDROCARBON SOLVENTS AROMATIC Benzene, toluene, xylene.
- 12. benzene • benzene is a colorless, flammable liquid with a pleasant odor. • it is used as a solvent in many areas of industries, such as rubber and shoe manufacturing, • in production of styrene, phenol and cyclohexane. • it is essential in the manufacture of detergents, pesticides and paint removers.
- 13. sources • Natural sources of benzene include volcanoes and forest fires. • Benzene is also a natural part of crude oil, gasoline, and cigarette smoke. • Benzene is widely used in the United States. • It ranks in the top 20 chemicals for production volume. • Also prepared industrially.
- 14. HEALTHS EFFECTS • Carcinogenic • benzene causes leukemia • Enter the body by inhalation & pass through the skin. • high exposure to benzene may cause irregularities in the heart beat which can lead to death. • aplastic anemia • Decreased ovaries size in women. • Abnormal amount of chromosomes in sperms in males.
- 15. ALIPHATIC HYDROCARBON SOLVENTS • Acetaldehyde , formaldehyde, ketones.
- 16. FORMALDEHYDE • formaldehyde is a colourless, flammable gas or liquid that has pungent, suffocating odour. • it is a volatile organic compound, which is an organic compound that easily becomes a vapour or gas. • it is also naturally produced in small, harmless amounts in the human body.
- 17. sources • Formaldehyde is found in cigarette smoke and also can be formed in the environment during the burning of fuels or household waste. • Very small amounts found naturally in the human body. • found in new manufactured or mobile homes than in older conventional homes.
- 18. • Used manufacturing urea formaldehyde resins, used in particleboard product. • chemical intermediate. • extensively used as an insulating material.
- 19. IMPACTS • acute animal tests in rats and rabbits have shown formaldehyde to have high acute toxicity from inhalation, oral and dermal exposure. • coughing, wheezing, chest pains and bronchitis in humans.
- 20. HALOGENATED SOLVENTS • These are the solvents that contains C, H along with the halogens. • Have more pungent aroma than hydrocarbons. • Highly effective solvents. • Chlorinated form has some safety risks.
- 21. HALOGENATED SOLVENTS • E.g. Carbon tetrachloride chloroform trichloroethylene tetrachloroethylene methyl chloroform CFCs
- 22. CHLOROFLUOROCAR BONS • CFCs is an organic compound Which are produced as volatile derivatives of methane, ethane and propane. • Halogenation of hydrocarbon gives the CFCs.
- 23. Sources • Sources of chlorofluorocarbons are as follows; • Aerosol Sprays • Air conditioners • Refrigerators • Industries making all these products.
- 24. IMPACTS • Direct exposure to some types of CFCs can cause unconsciousness, shortness of breath and irregular heart beat. • confusion, drowsiness, coughing, sore throat, eye redness and pain. • direct skin contact with CFCs can cause frostbite or dry skin.
- 25. • Cause ozone depletion. • harmful ultraviolet rays reach the earth. • Exposure to increased ultraviolent rays can cause skin cancer, cataracts and weakened immune systems.
- 28. IMPACT ON PLANTS • Growth rate effects. • Cause diseases • Disturbs their life cycle
- 29. IMPACT ON MARINE LIFE • Disrupt food chain • Reduce survival rate • Damage early development stages
- 30. Conti…….. • Some of halo hydrocarbons cause persistent water pollution. • These are depressants on CNS in humans. • Methyl chloroform cause impaired memory. • CCl₄ most potent to cause hepatotoxicity. • Neurotoxicity in humans by chloroform, CCl₄ & trichloroethylene.
- 31. PREVENTIVE MEASURES • Do not wash benzene into the sewage system. it may cause an explosion. benzene is a hazardous waste. • Be careful while dealing with such solvents. • Reduce the use of sprays, fire suppressors, air conditioners. • Wear specific uniforms while working in industries to reduce the exposure. • Ceasing to use the chemical.
- 32. GREEN SOLVENTS• Green solvents are environmentally friendly solvents or bio solvents, which are derived from the processing of agricultural crops. • The use of petrochemical solvents are the key to the majority of chemical processes but not without severe implications on the environment.
- 33. • The best way to reduce the hazardous solvent’s effect is to replace them with the green solvents. • substitution of benzene by Cyclohexane or toluene.