Effects of Alkanes and Cycloalkanes in Human and Environment

1. Effects of Alkanes and Cycloalkanes in Human and Environment Advantages and Disadvantages By: Emalyn Llona

2. Advantages of Alkanes Some advantages ... • Probably the major use/advantage of Methane is that it is what we call "Natural Gas," and as such is a MAJOR fuel worldwide! We all are aware of the tremendous value of a relatively easily delivered fuel to our homes, businesses, and factories. • Methane [CH4] is also is a basic "building block" for literally dozens, or possibly hundreds, of compounds which we use to make literally thousands of products we use every day. One example is the multitude of different plastics.

3. In the "new" technology vehicles designed to burn Hydrogen, billions of tons of natural gas [Methane] will be thermally "steam cracked" into Hydrogen for use as a motor vehicle fuel, but I don't know yet what plans "they" have for the billions of tons of pure carbon which will be left over from the cracking process.

4. Disadvantages of Alkanes Some disadvantages ... • It is a main contributor to global warming, as it is one of the "greenhouse" gasses which cause entrapment of infrared energy [heat] within the atmospheric envelope around the Earth. • It is very dangerous to the human body, in that high enough concentrations in the air can result result in suffocation of air breathing creatures, AND in the proper concentration in the air, it is very highly explosive!

5. Examples of Alkanes we use everyday • Methane • Ethane • Propane • Butane

6. Advantages of methane • Methane is used in industrial chemical processes and may be transported as a refrigerated liquid (liquefied natural gas, or LNG).

7. Disadvantages of Methane • affects the degradation of the ozone layer. • Methane in the Earth's atmosphere is an important greenhouse gas with a global warming potential of 25 compared to CO2 over a 100-year period (although accepted figures probably represents an underestimate. • it is extremely flammable and may form explosive mixtures with air.

8. violently reactive with oxidizers, halogens, and some halogen-containing compounds. • an asphyxiant and may displace oxygen in an enclosed space. • Methane off-gas can penetrate the interiors of buildings near landfills and expose occupants to significant levels of methane. Some buildings have specially engineered recovery systems below their basements to actively capture this gas and vent it away from the building.

9. Traditionally, industrial nations have relied upon fossil fuels like oil, coal and natural gas to power our economies. Fossil fuels are an example of this type of energy resources. There are many specific types of non-renewable energy, including: * Various types of coal such as anthracite, bituminous coal, and lignite * Petroleum products used to make gasoline, diesel fuel, and heating oil * Natural gas, the methane in which is extracted and used as fuel * The uranium ore used in nuclear fission reactors is a non-renewable energy resource

10. Advantages: 1. Widely available, at least currently 2. Simple to use and engineer, given that it is based upon a simple combustion process 3. Inexpensive 4. Easy to transport and distribute Disadvantages: 1. Contributing to the warming of the planet, or global warming 2. Causes pollution such as acid rain, which hurts animals and plants around the world 3. Potential source of global political unrest, given that many nations are reliant upon other nations for these non-renewable energy resources

11. Ethane Ethane is isolated on an industrial scale from natural gas, and as a byproduct of petroleum refining. Its chief use is as petrochemical feedstock for ethylene production. After methane, ethane is the second-largest component of natural gas. Natural gas from different gas fields varies in ethane content from less than 1% to over 6% by volume. Today, however, ethane is an important petrochemical feedstock, and it is separated from the other components of natural gas in most well-developed gas fields. Ethane can also be separated from petroleum gas, a mixture of gaseous hydrocarbons that arises as a byproduct of petroleum refining.

12. The chief use of ethane is in the chemical industry in the production of ethene (ethylene) by steam cracking. When diluted with steam and briefly heated to very high temperatures (900 °C or more), heavy hydrocarbons break down into lighter hydrocarbons, and saturated hydrocarbons become unsaturated.

13. Experimentally, ethane is under investigation as a feedstock for other commodity chemicals. Oxidative chlorination of ethane has long appeared to be a potentially more economical route to vinyl chloride than ethene chlorination. Many processes for carrying out this reaction have been patented, but poor selectivity for vinyl chloride and corrosive reaction conditions (specifically, a hydrochloric acid-containing reaction mixture at temperatures greater than 500 °C) have discouraged the commercialization of most of them.

14. Safety • At room temperature, ethane is a flammable gas. When mixed with air at 3.0%–12.5% by volume, it forms an explosive mixture. • Some additional precautions are necessary where ethane is stored as a cryogenic liquid. Direct contact with liquid ethane can result in severe frostbite. In addition, the vapors evaporating from liquid ethane are, until they warm to room temperature, heavier than air and can creep along the ground or gather in low places, and if they encounter an ignition source, can flash back to the body of ethane from which they evaporated. • Containers recently emptied of ethane may contain insufficient oxygen to support life. Beyond this asphyxiation hazard, ethane poses no known acute or chronic toxicological risk. It is not known or suspected to be a carcinogen.

15. SAFETY FOR ODORIZED PROPANE Identification Product Name: Odorized Commercial Propane Chemical Name: Propane Chemical Family: Paraffinic Hydrocarbon Formula: C3H8 Synonyms: Dimethylmethane, LP-Gas, Liquefied Petroleum Gas (LPG), Propane, Propyl Hydride

16. Hazards of Propane Flammable liquefied gas under pressure. Keep away from heat, sparks, flame, and all other ignition sources. Vapor replaces oxygen available for breathing and may cause suffocation in confined spaces. Use only with adequate ventilation. Reliance upon detection of odor may not provide adequate warning of potentially hazardous concentrations. Vapor is heavier than air; may collect at low levels. Liquid can cause freeze burn similar to frostbite.

17. POTENTIAL HEALTH EFFECTS INFORMATIONROUTES OF EXPOSURE: Inhalation: Asphyxiation. Before suffocation could occur, the lower flammability limit of propane in air would be exceeded, possibly causing both an oxygen-deficient and explosive atmosphere. Exposure to concentrations >10% may cause dizziness. Exposure to atmospheres containing 19% or less oxygen will bring about unconsciousness without warning. Lack of sufficient oxygen may cause serious injury or death. Eye Contact: Contact with liquid can cause freezing of tissue. Skin Contact: Contact with liquid can cause frostbite. Skin Absorption: None. Ingestion: Ingestion is not expected to occur in normal use. However, liquid can cause freeze burn similar to frostbite. Chronic Effects: None

18. Ecological Information No adverse ecological effects are expected. Propane does not contain any Class I or Class II ozone-depleting chemicals. Propane is not listed as a marine pollutant.

19. Butane

20. Hazards of Butane • Effects on Animals Contact with liquid butane can cause frostbite. This gas is also an anesthetic and aphyxiant in animals at very high concentration. Although butane is mildly to moderately irriating to rabbit skin, it does not produce ocular or respiratory tract irritation. Exposed dogs to high concentration of liquid butane can cause stroke, increase cardiovascular disease, left ventricular and aortic pressures.

21. Effects on Human • Transient blurring may result if liquid butane is accidentally sprayed on eyes from a cigarette lighter. • However, contact of butane gas on eyes may not cause irritation. • But contact with the liquefied form may cause frostbite into the eyes and skin. • Exposure to high concentration within a short period of time may cause drowsiness but does not appear to cause systematic effects. • Inhalation of children of aerosol sprays which contain butane, isobutane, and propane can cause to seizures, hypotension and cardiovascular defect. • Visual hallucinations, increased irritability, and social withdrawal are some effects to adolescents which are exposed to this gas everyday. • Another effect to people who are exposed to high concentration can affect central nervous system, causing narcosis and aphyxiation,

22. Examples of Cycloalkanes • Cyclopropane • Cyclohexane

23. Cyclopropane • Cyclopropanes are a class of organic compounds containing a cyclopropane ring, in which one or more hydrogen atoms are replaced by other groups. These compounds are found in biomolecules and many synthetic substances. For instance, the pyrethrum insecticides found in certain Chrysanthemum species contain a cyclopropane ring. Many modified derivatives, called pyrethroids, have been prepared • Cyclopropane is an anaesthetic when inhaled. In modern anaesthetic practice, it has been superseded by other agents, due to its extreme reactivity under normal conditions: When the gas is mixed with oxygen there is a significant risk of explosion.

24. Anaesthesia Cyclopropane was introduced into clinical use by the American anaesthetist Ralph Waters who used a closed system with carbon dioxide absorption to conserve this then-costly agent. Cyclopropane is non-irritant and sweet smelling. It is a relatively potent agent and has a blood gas partition coefficient comparable to nitrous oxide. This meant induction of anaesthesia by inhalation of cyclopropane and oxygen was rapid and not unpleasant. Prolonged anaesthesia caused "cyclopropane shock" during recovery and for this reason, and its explosive nature, it was latterly used only for induction of anaesthesia. Cylinders and flow meters were coloured orange.

25. Because of the strain in the carbon-carbon bonds of cyclopropane, the molecule has an amount of potential energy, indicated by its high heat of combustion. • At room temperature, sufficient volumes of liquifiedcyclopropane will self-detonate. Cyclopropane is dangerous to handle and manufacture, and is no longer used for anaesthesia.

26. Cyclohexanes Cyclohexane is a colorless, flammable liquid. It occurs naturally in petroleum crude oil, in volcanic gases, and in cigarette smoke. Exposure to cyclohexane can occur in the workplace or in the environment following releases to air, water, land, or groundwater. Exposure can also occur when people use products that contain cyclohexane or when they smoke cigarettes. Cyclohexane enters the body when breathed in with contaminated air or when consumed with contaminated food or water. It can also be absorbed through skin contact. Cyclohexane is not likely to remain in the body due to its breakdown and removal in exhaled air and in urine.

27. Cyclohexane evaporates when exposed to air. It dissolves when mixed with water. Most direct releases of cyclohexane to the environment are to air. Cyclohexane also evaporates from water and soil exposed to air. Once in air, it is expected to break down to other chemicals. Because it is a liquid that does not bind well to soil, cyclohexane that makes its way into the ground can move through the ground and enter groundwater. Plants and animals living in environments contaminated with cyclohexane can store small amounts of the chemical.

28. How cyclohexane affect human and the environment? Effects of cyclohexane on human health and the environment depend on how much cyclohexane is present and the length and frequency of exposure. Effects also depend on the health of a person or the condition of the environment when exposure occurs. Breathing large amounts of cyclohexane for short periods of time adversely affects the human nervous system. Effects range from headaches to anesthesia, tremors, and convulsions. Contact with cyclohexane liquid or vapor can damage the eyes. These effects are not likely to occur at levels of cyclohexane that are normally found in the environment.

29. Human health effects associated with breathing or otherwise consuming smaller amounts of cyclohexane over long periods of time arenot known. Information about cyclohexane's potential to cause cancer,developmental effects, or reproductive effects either does not exist oris not adequate. Studies show that repeat exposure to large amounts ofcyclohexane in air causes nervous system effects, eye damage, andrespiratory effects in animals. The cyclohexane industry is nostudying how its chemical affects the reproductive system and thedevelopment ofthe fetus of animals.

30. Cyclohexane by itself is not likely to cause environmental harm at levels normally found in the environment. Cyclohexane can contribute to the formation of photochemical smog when it reacts with other volatile organic carbon substances in air.

31. Hazard Identification Inhalation Breathing high concentrations may be harmful. Mist or vapor can irritate the throat and lungs. Breathing this material may cause central nervous system depression with symptoms including nausea, headache, dizziness, fatigue, drowsiness, or unconsciousness.

32. Eye Contact This product can cause transient mild eye irritation with short-term contact with liquid sprays or mists. Symptoms include stinging, watering, redness, and swelling. • Skin Contact This material can cause skin irritation. The severity of irritation will depend on the amount of material that is applied to the skin and the speed and thoroughness that it is removed. Symptoms include redness, itching, and burning of the skin. Repeated or prolonged skin contact can produce moderate irritation (dermatitis).

33. Ingestion If swallowed, this material may irritate the mucous membranes of the mouth, throat, and esophagus. It can be readily absorbed by the stomach and intestinal tract. Symptoms include a burning sensation of the mouth and esophagus, nausea, vomiting, dizziness, staggered gait, drowsiness, loss of consciousness and delirium, as well as additional central nervous system effects. Due to its light viscosity, there is a danger of aspiration into the lungs during swallowing and subsequent vomiting. Aspiration can result in severe lung damage or death. Cardiovascular effects include shallow rapid pulse with pallor (loss of color in the face) followed by flushing (redness of the face).

34. Chronic Health Effects Prolonged and/or repeated contact may cause skin irritation and inflammation. Symptoms include defatting, redness, blistering, lesions, and scaly dermatitis.