For this case study, ensure that you read the information from the case study scenario and address the following points.
Describe safety precautions that you will take to perform the fieldwork for this project. (Note: You do not know what specific materials are present at the site initially.)
Identify all of the hazardous materials (or potentially hazardous materials) observed and their classification (acid, base, water-reactive, or air reactive). Describe their uses and chemical properties.
Discuss at least four potential interactions between these hazardous materials, including their chemical reactions, showing the reactants and products. Identify any associated hazards with the products.
Discuss and justify any actions taken onsite and recommendations that will be included in your report to your client.
UNIT III STUDY GUIDE
Chemistry of Acids/Bases and
Water/Air Reactive Materials
Course Learning Outcomes for Unit III
Upon completion of this unit, students should be able to:
2. Analyze chemical interactions as they relate to control of potential hazards.
2.1 Determine the chemical interactions and use of acids, bases, water-reactive materials, airreactive materials, and any associated hazards.
4. Determine strategies for dealing with chemical properties of specific types of hazardous substances.
4.1 Discuss recommended response actions or strategies in dealing with chemical properties,
including potential releases of acids, bases, water-reactive materials, and air-reactive materials.
Course/Unit
Learning Outcomes
2.1
4.1
Learning Activity
Unit Lesson
Chapter 8, pp. 287322
Chapter 9, pp. 327362
Unit III Case Study
Unit Lesson
Chapter 8, pp. 287322
Chapter 9, pp. 327362
Unit III Case Study
Required Unit Resources
Chapter 8: Chemistry of Some Corrosive Materials, pp. 287322
Chapter 9: Chemistry of Some Water- and Air-Reactive Substances, pp. 327362
Unit Lesson
In Unit III, you will study the chemistry of corrosive materials (acids and bases), water-reactive materials, and
air-reactive (pyrophoric) materials. These topics are covered in Chapters 8 and 9 of your textbook.
Most likely, all of you have heard of acids and bases. If you had chemistry in high school, your first laboratory
experiment was probably taking the pH of various materials. Then, there is the adjustment or neutralization of
some aqueous solutions to change the pH or bring the pH to 7.0. In Chapter 8, we will learn the nature and
properties of acids and bases and the differences between strong and weak acids and bases (i.e.,
concentrated versus dilute acids and oxidizing versus non-oxidizing acids). The concept of pH scale is
reintroduced, including the pH values of some aqueous solutions. Specific information regarding the uses,
properties, and chemical reactions associated with commonly encountered acids and bases is also covered in
Chapter 8 of the textbook.
In Chapter 9 of the textbook, we will learn the reactions of certain materials with water. You will find out that
water is not always the best or appropriate material to put out a fire.
Corrosive Materials
When we hear or think of corrosion, we normally associate it with some metal that is rusting, pitting, or
deteriorating. That association is correct, as corrosion is defined as the deterioration of a material (usually a
metal) that results from a chemical or electrochemical reaction with its environment (National Association of
OSH 3308, Interactions of Hazardous Materials
1
Corrosion Engineers [NACE] International, n.d.). Corrosion can cause hazardous
and,
oftentimes,
expensive
UNIT
x STUDY
GUIDE
damage to everything from vehicles, home appliances, and water and wastewater
Titlesystems to pipelines,
bridges, and public buildings (NACE International, n.d.). This brings us to the substances or materials that can
cause this corrosion phenomenon. Acids and bases are the best examples of corrosive materials. Just
imagine if we get exposed to corrosive materials; our bodies can also deteriorate!
When dissolved in water, an acid generates hydrogen ions (H+) while a base produces hydroxide ions (OH-).
As you may recall from Chapter 4 in Unit I, an ion is an atom (or group of atoms bound together) with a net
electric charge due to the loss or gain of electrons (Meyer, 2020, p. 21). In other words, an ion carries a
positive charge (cation) or negative charge (anion). Acids and bases that yield a relatively high concentration
of hydrated hydrogen and hydroxide ions are called strong acids and bases, respectively (Meyer, 2020). In
contrast, acids and bases that do not readily ionize (break apart) or give up the hydrogen or hydroxide ions
are called weak acids and bases. The ability of the acids and bases to form ions in water is what makes them
corrosive.
An acid participates in a chemical reaction as either an oxidizing acid or a non-oxidizing acid. Concentrated
acid is when it is at its strongest concentration. It can be diluted to reduce its strength with the addition of
water.
Acids
(Meyer, 2020)
OSH 3308, Interactions of Hazardous Materials
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pH scale
UNIT x STUDY GUIDE
Title
pH is a measurement to indicate if an aqueous
solution is acidic (pH of 0 to 7
to 14). The pH of an aqueous solution or
mixture can be measured with a meter or with
pH paper. In a commercial chemical
laboratory, the pH of a solid (soil/solid residue
samples) can also be measured by adding
deionized or distilled water to the solid (usually
crushed, as needed). Note that the pH of a
solution is temperature dependent, which is
why there are usually differences between
onsite/field and laboratory pH measurements.
Regulatory agencies that require pH
measurements want the pH measured onsite
within 15 minutes of sampling.
Illustration of pH scale value.
(A72I72I721, n.d.)
Acids act as corrosive materials by reacting
with metals, metallic oxides, metallic carbonates, and skin tissue (refer to sections 8.6A to 8.6D). Bases act
as corrosive materials by also reacting with metals and skin tissue (refer to section 8.6E and 8.6F). The
textbook covered some of the common acids and bases that are encountered in practice by environmental
health and safety and fire service professionals. Please note that there are workplace regulations involving
acids and bases as well as U.S. Department of Transportation (DOT) requirements when they are being
transported.
Regarding incidents involving the release of corrosive material (after the material has been identified as a
corrosive material), emergency responders should consider the following actions: dilute the material if
appropriate or neutralize with a solid material. The Emergency Response Guidebook (ERG) recommends
initial isolation and protective action zone distances. Other incidents that may also come up involving
corrosive materials are acid or alkali poisoning incidents. Poisoning incidents may include corrosive materials
that inadvertently get splashed into or on an individuals eyes or skin or may even be ingested.
Resource Conservation and Recovery Act (RCRA) Corrosivity
The corrosivity characteristic is one of the criteria used by the U.S. Environmental Protection Agency (EPA)
and some states or local regulatory agencies to determine if a waste is considered hazardous waste. It is
mostly determined by measuring the pH such that an aqueous liquid with a pH of less than or equal to 2.0, or
equal or greater than 12.5, is considered hazardous waste (EPA, n.d.). Visit the “Defining Hazardous Waste:
Listed, Characteristic and Mixed Radiological Wastes” webpage on the EPA website for additional
information.
Water-Reactive and Air-Reactive Materials
We often assume that the use of water is the best way to put out a fire or make the material less hazardous
because of its diluting or cooling effects, not to mention its availability. However, this is not always the case
since certain materials react with water to produce flammable gases that ignite spontaneously. In some
cases, toxic or corrosive products can also be formed from the reaction of certain hazardous material with
water. The term used to describe the interaction of water with another substance is called hydrolysis (Meyer,
2020).
Some materials ignite spontaneously upon exposure to ambient air, typically posing the risk of fire and
explosion (Meyer, 2020). These are known as pyrophoric or air-reactive materials. Their reactions may start
the inherent hazard with the moisture in the air as they are released from containment. Pyrophoric materials
are sometimes stored and processed under oil within an enclosed, oxygen-free, or dry atmosphere to avoid
such hazardous reactions. When shipping water-reactive materials, the Occupational Safety and Health
Administration (OSHA) regulates their transportation as dangerous-when-wet materials, spontaneously
combustible materials, flammable solids, or corrosive materials.
OSH 3308, Interactions of Hazardous Materials
3
Alkali Metals
UNIT x STUDY GUIDE
Title
In this unit, the properties of the alkali metals lithium, sodium, and potassium are discussed. If you recall from
the periodic table, these metals belong to the same family. When sodium or potassium react with water, the
hydrogen that is formed bursts spontaneously into flames. With lithium, the hydrogen generated does not
immediately ignite. Regarding lithium, you may associate it with batteries. There are two types of lithium
batteries: primary (disposable and non-rechargeable) and secondary (used in laptop computers,
smartphones, drones); both types can pose a fire risk. You may have heard that airlines are prohibiting lithium
batteries in luggage. It is because if not properly packed, the batteries could overheat and burst into flames
(Peterson, 2015).
Various lithium batteries
(Aleximx, n.d.; Lightboxx, n.d.; Shin, n.d.)
Combustible Metals
Other metals that include magnesium, titanium, aluminum, zirconium,
and zinc are typically difficult to ignite when in bulk but may self-ignite in
their divided forms (chips, trimmings, filings, or shavings) without an
ignition source. These metals represent the fuels of Class D fires (Meyer,
2020). The finely divided forms of combustible metals are regarded as
both water-reactive and pyrophoric to varying degrees.
Combustible Dust
Rustic metal fire basket
(Powerofflowers, n.d.)
A category of material that poses a fire or explosion hazard is
combustible dust. Although it is not specifically discussed in the
textbook, we need to be aware that incidents involving combustible
dust explosions are more common than we think. According to
OSHA (n.d.), combustible dust is any combustible material that can burn rapidly and become explosible when
in a finely divided form that is suspended in the air in the right concentration under certain conditions. Even
materials that do not burn in larger pieces (such as aluminum or iron), given the proper conditions, can be
explosible in dust form.
Materials that can pose an explosive hazard in dust form can be found in many industries that include food
(e.g., candy, sugar, spice, starch, flour, feed), grain, tobacco, plastics, wood, paper, pulp, rubber, furniture,
textiles, pesticides, pharmaceuticals, dyes, coal, metals (e.g., aluminum, chromium, iron, magnesium, and
zinc), and fossil fuel power generation. For information on regulations, training, prevention, and mitigation of
combustible dust-related fires/explosions, review the “Combustion Dust: An Explosion Hazard” webpage on
OSHAs website.
Other Water and Air Reactive Materials
Other water- and air-reactive materials that are discussed in the textbook are aluminum alkyl compounds and
their derivatives, ionic hydrides, metallic phosphides, and metallic carbides. Certain substances react with
water to produce hydrogen chloride vapor or hydrochloric acid, such as aluminum chloride and phosphorus
OSH 3308, Interactions of Hazardous Materials
4
trichloride. Some substances such as acetic anhydride and acetyl chloride also
produce
aceticGUIDE
acid when they
UNIT
x STUDY
react with water.
Title
In summary, when handling, storing, or transporting water-reactive and pyrophoric materials, caution must be
taken to avoid their contact with water. OSHA and DOT requirements must be followed to avoid hazardous
incidents involving these materials.
References
Aleximx. (n.d.). Set of button cell batteries, 3D rendering (ID 75102930) [Photograph]. Dreamstime.
https://www.dreamstime.com/stock-illustration-set-button-cell-batteries-d-rendering-whitebackground-image75102930
A72I72I721. (n.d.). Creative vector illustration of pH scale value isolated on background. Chemical art design
infographic (ID 118823200) [Illustration]. Dreamstime. https://www.dreamstime.com/creative-vectorillustration-ph-scale-value-isolated-background-chemical-art-design-infographic-abstract-conceptgraphic-l-image118823200
Lightboxx. (n.d.). Lithium-ion batteries Isolated on white (ID 137394902) [Photograph]. Dreamstime.
https://www.dreamstime.com/lithium-ion-batteries-isolated-white-d-rendering-lithium-ion-batteriesisolated-white-image137394902
Meyer, E. (2020). Chemistry of hazardous materials (L. Mauerman, Ed.; 7th ed.). Pearson.
National Association of Corrosion Engineers International. (n.d.). Corrosion basics.
https://www.nace.org/resources/general-resources/corrosion-basics
Occupational Safety and Health Administration. (n.d.). Combustible dust in industry: Preventing and mitigating
the effects of fire and explosions. https://www.osha.gov/dts/shib/shib073105.html
Peterson, B. (2015, October). The FAA is freaked-out on lithium batteries on planes. Popular Mechanics.
https://www.popularmechanics.com/flight/a17824/faa-lithium-ion-batteries
Powerofflowers. (n.d.). Rustic metal fire basket. Burning wood in fire basket (ID 171870711) [Photograph].
Dreamstime. https://www.dreamstime.com/rustic-metal-fire-basket-burning-wood-image171870711
U.S. Environmental Protection Agency. (n.d.). Defining hazardous waste: Listed, characteristic and mixed
radiological wastes. https://www.epa.gov/hw/defining-hazardous-waste-listed-characteristic-andmixed-radiological-wastes#corrode
Shin, C. K. (n.d.). New lithium polymer rechargeable batteries (ID 102128646) [Photograph]. Dreamstime.
https://www.dreamstime.com/new-lithium-polymer-rechargeable-batteries-new-lithium-polymerrechargeable-batteries-difference-connector-image102128646
Suggested Unit Resources
In order to access the following resources, click the links below.
Review the PowerPoint presentations on Chapters 8 and 9 to supplement the textbook reading and lesson
content.
Access the Chapter 8 PowerPoint Presentation (PDF version of the Chapter 8 presentation).
Access the Chapter 9 PowerPoint Presentation (PDF version of the Chapter 9 presentation).
OSH 3308, Interactions of Hazardous Materials
5
Learning Activities (Nongraded)
UNIT x STUDY GUIDE
Title
Nongraded Learning Activities are provided to aid students in their course of study. You do not have to submit
them. If you have questions, contact your instructor for further guidance and information.
In order to access the following resources, click the links below.
Review some of the key concepts from Chapter 8 by completing the Chapter 8 Practice Quiz (PDF version of
the Chapter 8 practice quiz). You can attempt as many times as you wish.
Review some of the key concepts from Chapter 9 by completing the Chapter 9 Practice Quiz (PDF version of
the Chapter 9 practice quiz). You can attempt as many times as you wish.
OSH 3308, Interactions of Hazardous Materials
6
