Chemistry of hazardous materials meyer

Hazardous Materials

OHS 3640, Interactions of Hazardous Materials 1

Course Learning Outcomes for Unit VI Upon completion of this unit, students should be able to:

5. Classify hazardous materials according to Department of Transportation (DOT) classification and warning systems. 5.1 Identify the hazard class, descriptions, labels, markings, and placards that DOT requires when

transporting hazardous organic compounds. 5.2 Describe the importance of having regulations for transporting hazardous organic compounds.

6. Determine strategies for dealing with chemical properties of specific types of hazardous substances.

6.1 Identify the chemical properties, uses, and ill effects associated with common hazardous organic compounds as related to the tasks and safety of an EHS & FS professional.

9. Examine widely used hazardous material classification and labeling systems.

9.1 Interpret the new 16-point format requirement of the new Global Harmonized System of Classification and Labeling of Chemical Substances (GHS) Safety Data Sheet (SDS) as it relates to organochlorine pesticides.

9.2 Utilize the new GHS SDS to assess and mitigate workplace hazards related to organochlorine pesticides.

Course/Unit Learning Outcomes

Learning Activity

5.1

Unit VI Lesson Chapter 12 Reading Chapter 13 Reading Unit VI Essay

5.2

Unit VI Lesson Chapter 12 Reading Chapter 13 Reading Unit VI Essay

6.1

Unit VI Lesson Chapter 12 Reading Chapter 13 Reading Unit VI Essay

9.1

Unit VI Lesson Chapter 12 Reading Chapter 13 Reading Unit VI Essay

9.2

Unit VI Lesson Chapter 12 Reading Chapter 13 Reading Unit VI Essay

Reading Assignment Chapter 12: Chemistry of Some Hazardous Organic Compounds: Part I, pp. 466-527

UNIT VI STUDY GUIDE

Chemistry of Some Hazardous Organic Compounds

OHS 3640, Interactions of Hazardous Materials 2

UNIT x STUDY GUIDE

Title

Chapter 13: Chemistry of Some Hazardous Organic Compounds: Part II, pp. 533-600

Unit Lesson In this unit, we will study the chemistry of some hazardous organic compounds. Organic compounds are all around us. They are the building blocks and end products of a wide variety of many commercial products such as rubber, fuels, pharmaceuticals, cosmetics, detergents, coatings, and agrichemicals. As useful as they are, organic compounds have inherent hazardous properties of which environmental health and safety (EHS) and fire science (FS) personnel must be aware. For example, organic compounds are usually flammable and some are toxic. Chapters 12 and 13 in your textbook focus on more simple organic compounds. In a subsequent unit, we will study the more complex forms of organic compounds that include polymers and explosives. Note: To better understand this unit, refer to the textbook to see the structural formulas of the various organic compounds as they are not easy to present in a Word document. There is also a short PowerPoint presentation attached in the Suggested Reading that illustrates structures of organic compounds. CHAPTER 12: Chemistry of Some Hazardous Organic Compounds: Part I What are organic compounds?

 Organic compounds have one or more carbon (C) atoms in their chemical makeup or structure. Some examples are methane (CH4), carbon monoxide (CO2), and polychlorinated biphenyls (PCBs).

 Carbon atoms can share electrons with other non-metallic atoms, such as carbon disulfide (CS2) and methane (CH4). When carbon shares electrons with a hydrogen atom, the resulting compound is known as a hydrocarbon. Most organic compounds are hydrocarbons (HC).

 Carbon atoms can also share electrons with other carbon atoms. In this case, their sharing can be by single bond (C-C), double bond (C=C), or triple bond (C≡C) (Meyer, 2014).

Hydrocarbons (HC) are divided into the following:

 Aliphatic hydrocarbons do not contain aromatic or aromatic-like structures (the simplest aromatic HC is benzene).

 Aromatic hydrocarbons contain a benzene ring; aromatic does not necessarily reflect odors, but denotes specific chemical and physical properties (Pine, 1987). A benzene ring has six carbon atoms with three double bonds. The structural formula is shown below:

Structural formula of a benzene ring (Jynto, 2010)

OHS 3640, Interactions of Hazardous Materials 3

UNIT x STUDY GUIDE

Title

ALKANES and CYCLOALKANES Alkane is a hydrocarbon with a single bond. The bond could be with hydrogen (C-H) or with another carbon (C-C). Refer to Table 12.1 on page 471 in our textbook for the simple alkanes and their names. The general chemical formula for alkanes is:

CnH2n+2 where n = non zero integer. Example: Propane has three carbons, so n=3; therefore, the number of H is 8 (Meyer, 2014). Propane can then be written as C3H8 or as shown below: Cycloalkanes are alkanes arranged in a cyclic ring (single bonds). The general formula is CnH2n. See page 472 of your textbook for the illustration of some examples such as cyclopropane and cyclobutane. Alkanes and cycloalkanes are known as saturated hydrocarbons since the four bonding electrons of each carbon atom are shared with the bonding electrons of four other atoms; bonds are stronger/more stable compared to the double or triple bonds (which we will cover later in this unit) (Meyer, 2014). Common system of nomenclature: Molecular and structural formulas of the alkanes and cycloalkanes are discussed on pages 470-471 of your textbook. It is a straight-forward discussion, so read them to get a foundation of how to name organic compounds and write their formulas. IUPAC system of nomenclature: IUPAC (International Union of Pure and Applied Chemistry) has established some rules on naming the more complex organic compounds to ensure uniformity (Meyer, 2014). The rules for each type of organic compound are listed in the textbook with examples. Familiarize yourself with them so you can identify most organic compounds that you encounter in practice. Alkenes, dienes, trienes, and the cyclos: These HCs have double bonds that are considered as unsaturated HCs (more reactive than the saturated HCs) (Meyer, 2014). Alkenes have the general formula of CnH2n+2. Cycloalkenes have the general formula of CnH2n-2. Just like with the alkanes, there are also rules in naming them (see page 477 in your textbook). In the names, the prefix depends on the number of carbon atoms, and the suffix is ene. Alkynes: Alkynes have one or more triple bonds, also considered unsaturated HCs (Meyer, 2014). Their general formula is CnH2n-2. The simplest alkyne is C2H2 known as acetylene. If we are to follow the IUPAC system, the other name for acetylene is ethyne (two carbon atoms with a triple bond). Common aliphatic HC: Now that you understand the basics, some common organic compounds that may be encountered in your daily work or life are listed below and covered in the textbook. These are all very flammable gases, so shippers are required to follow DOT regulations during their transport.

 Methane is the simplest aliphatic HC (CH4); it is the primary constituent of natural gas, also landfill gas. It is an odorless gas which is why commercially mercaptan (garlic or rotten egg smell) is added so it can be detected if there is a leak.

 LPG (liquid petroleum gas) is propane and butane or a mixture of both.

 Ethylene (ethane) and propylene (propene) are simple alkenes (double bonds).

 Acetylene, as mentioned earlier, is the simplest alkyne (triple bond) (Meyer, 2014). AROMATIC HC Benzene, Toluene, and Xylene (BTX): These are commonly encountered aromatic HCs; see Table 12.12 on page 496 of your textbook for a list of their physical properties. They have commercial uses but may impact worker’s health if their vapors are inhaled. BTX are considered volatile organic compounds. Years ago, when

Structural formula of propane (NEUROtiker, 2009)

OHS 3640, Interactions of Hazardous Materials 4

UNIT x STUDY GUIDE

Title

underground storage tank regulations first came out, there were a lot of leaking underground tanks found, mostly from gasoline stations. The contaminants of most concern, which also served as indicators of a gasoline leak, were BTX. Benzene is a known human carcinogen (Meyer, 2014). Polynuclear Aromatic HCs (PAHs): The only PAH that is of commercial importance is naphthalene (Meyer, 2014). For the most part, PAHs are formed as products of incomplete combustion. Specific PAHs are identified when a sample media is analyzed (considered semi-volatile organic compounds). Examples: PAHs are adsorbed in soot from fires, exhaust from diesel fired engines have PAHs, and landfill leachates could also have PAHs. There are also firefighting concerns with PAHs. Firefighters are vulnerable to airborne PAH exposure at fire scenes and potentially from the idling of diesel fueled fire trucks at the firehouse. For air quality and health reasons and more importantly to comply with the US Environmental Protection Agency (EPA) rules, some fire departments that use diesel fueled fire trucks have already upgraded or retrofitted their engines with air pollution control equipment. This helps to reduce diesel particulate emissions. Due to potential power loss issues, the EPA (2012) granted relief for fire engines and ambulances from these retrofit requirements. PETROLEUM AND PETROLEUM PRODUCTS Hydrocarbons are generally associated with petroleum. Petroleum (crude oil) is a complex chemical mixture of thousands of organic compounds that are mainly hydrocarbons (Meyer, 2014). Crude oil is found in subsurface rocks, the depth of which varies depending where in the world it is located. When crude oil is extracted, water and gas are also produced. The natural gas is processed at gas plants to break it down into methane (natural gas), propane, butane, and natural gasoline. The crude oil is processed at refineries resulting in gasoline, diesel, and kerosene products with which we are all familiar. In all production processes, starting from crude oil extraction from the ground to the transportation of the various products by trucks or pipelines to storage and use, there is the potential for exposure and emergency incidents. This is why EHS and FS professionals are needed. Hydraulic fracturing (fracking): An oil and gas development process that has recently gained popularity as well as controversy is hydraulic fracturing. This process involves injecting water under high pressure into bedrock formations to increase oil and/or gas flow to a well (United States Geological Survey, 2014). For additional information, visit http://www.usgs.gov/hydraulic_fracturing/. Its recent use is in the extraction of natural gas from shale (sedimentary rock). Most of you have probably heard of the Marcellus Shale—this is the largest known reservoir of natural gas, found underneath sizeable portions of West Virginia, New York, Ohio, and Pennsylvania (Meyer, 2014). This is why there is a lot of fracking being conducted on the east coast. Other HCs: The textbook also discusses chlorofluorohydrocarbons (CFCs) and polychlorinated biphenyls (PCBs), which I am sure you are all familiar with. You are required to read about these organic compounds for this unit. CHAPTER 13: Chemistry of Some Hazardous Organic Compounds: Part II In this chapter, we will cover the various classes of organic compounds and get familiar with their structures, their properties, and precautions in handling them. These compounds and their general chemical properties can be identified by knowing their functional groups. Their functional groups as well as their general formulas are listed in Table 13.1 on page 535 in your textbook. Depending on your job, it may be beneficial to memorize the functional groups and classes. Alcohols: The general formula is R-OH, where R is the arbitrary alkyl or aryl group and OH (hydroxyl) is the functional group (e.g., CH3-OH methyl alcohol or methanol). Simple alcohols such as methanol, ethanol, and isopropanol produce soot-less flames when they burn; this presents a problem when fighting fires involving them. Ethers: The general formula for simple ethers is R-O-R’ where R and R’ are arbitrary alkyl or aryl groups and –O- (oxy) is the functional group (e.g., CH3-O-CH2CH3 methyl ethyl ether). Ethers are highly volatile and flammable liquids and pose fire and explosion hazards. They can react with atmospheric oxygen to produce peroxo-organic compounds.

http://www.usgs.gov/hydraulic_fracturing/
OHS 3640, Interactions of Hazardous Materials 5

UNIT x STUDY GUIDE

Title

Aldehydes and ketones: Their functional group is called carbonyl (see the textbook for the illustrations of these organic compounds). The simplest aldehyde is formaldehyde. If you have done biology experiments/projects in high school, formaldehyde was used to preserve frogs and other specimens. A solution of formaldehyde that is commonly used as a disinfecting, sterilizing, and embalming agent is formalin. Formaldehydes are also released from equipment exhaust stacks during combustion of organic compounds such as natural gas. Acetone (also propanone or dimethyl ketone) is the simplest ketone. Other known ketones are methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK). These ketones are water soluble but highly flammable. Other organic compounds: Other classes of organic compounds that you should be familiar with are esters, organic acids, peroxo-organic compounds, and amines. The following are used as chemical warfare agents:

 nerve agents,

 vesicants,

 blood agents, and

 choking agents

References

Environmental Protection Agency. (2012). EPA grants relief for fire trucks and ambulances. Retrieved from http://www.epa.gov/otaq/highway-diesel/regs/420f12025.pdf

Jynto [Username]. (2010, August). Structural formula of a benzene ring [Image]. Retrieved from

https://commons.wikimedia.org/wiki/File:Benzene-2D-full.svg Meyer, E. (2014). Chemistry of hazardous materials (6th ed.). Upper Saddle River, NJ: Pearson. NEUROtiker. (2009, June). Structural formula of propane [Image]. Retrieved from

https://commons.wikimedia.org/wiki/File:Propan_Lewis.svg

Pine, S. (1987). Organic chemistry (2nd ed.). New York, NY: Mc-Graw-Hill. United States Geological Survey. (2014). Introduction to hydraulic fracturing. Retrieved from

http://www.usgs.gov/hydraulic_fracturing/

Suggested Reading Click here to access a PowerPoint presentation covering the basics of organic chemistry. Click here to access a PDF version of this presentation. The U.S. EPA maintains a webpage describing natural gas and their position on gas extraction. Links to other resources such as the U.S. EPA final report on hydraulic fracturing on drinking water resources can be found on this page. Environmental Protection Agency. (2012). Water: Hydraulic fracturing. Retrieved from

http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/wells_hydrowhat.cfm

https://online.waldorf.edu/CSU_Content/Waldorf_Content/ZULU/EmergencyServices/OSH/OSH3640/W14Cc/UnitVI_Presentation.ppsx
https://online.waldorf.edu/CSU_Content/Waldorf_Content/ZULU/EmergencyServices/OSH/OSH3640/W14Cc/UnitVI_Presentation.pdf
http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/wells_hydrowhat.cfm
OHS 3640, Interactions of Hazardous Materials 6

UNIT x STUDY GUIDE

Title

The U.S. Geological Survey provides a summary of the technology of hydrofracking or using water using high pressure to develop oil and gas wells. There are links to several assessment and resources that can be found on this page. United States Geological Survey. (2014). Introduction to hydraulic fracturing. Retrieved from

http://www.usgs.gov/hydraulic_fracturing/

http://www.usgs.gov/hydraulic_fracturing/