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2. Objectives
 Identify the importance of identifying a potential
corrosive risk
 Describe the common methods of identifying the
corrosive risk
 Describe the working definition of a corrosive material
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3. Corrosive Detection
 Because corrosive materials usually cause harm to
humans and electronic device, corrosive materials:
 burn or irritate humans
 Render any electronic instrument useless fairly quick
 Most monitors will work for a limited time than stop
working and you may not know this happened
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4. Corrosive Detection
 pH paper is one of the most dependable tools a
responder can use
 It is recommended that pH paper be one of the first
items down range at a chemical release
 Easiest way is to attach a strip to an object or another
instrument.
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5. pH Measurement
 Corrosives can be both acids or bases
 pH is the measure of the hydrogen ions in the solution
 The term pH can mean:
 Potential of hydrogen
 Power of hydrogen
 Percent of hydrogen ions
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6. pH Scale
 Most commonly 0-14
 Acids are materials with
pH of less than 7
 Bases are materials with
pH greater than 7
 A neutral material is
one that has a pH of 7
 Most states use a pH
between 5 and 9 for
legal neutral
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7. pH Measurement
 Common Materials
 Orange Juice pH 3
 Ammonia pH 13
 Vinger(acetic acid) pH 3
 Sodium hydroxide pH 13
 Acetone pH 7
 Hydrofluoric Acid pH 1
 Sulfuric Acid pH0
 Pepsi pH 2-3
 Hydrochloric Acid pH 0
 Oleum pH 1
 Gasoline pH 7
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8. pH Scale
 pH is based on a logarithmic scale
 When pH drops from 2 to 1 it is a factor of 10 stronger
 Material with a pH of 1 is 10 times more acidic than
something that has a pH of 2
 Material with a pH of 3 is 100 times more acidic than one
with a pH of 5
 Many responders forget about this logarithmic scale
when diluting a corrosive spill
 It takes a lot less dilution volume when going from 6 to 7
than from 1 to 7
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9. Concentration
 Corrosives come in a variety of concentrations
 Most corrosives have some percentage of water in them
 Some are diluted to low percentages
 Sulfuric acid comes in a range of concentrations
 2 percent sulfuric is known as spent pickle liquor
 30-37 percent is used in car batteries
 98 percent is used in laboratories or industrial settings
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10. Concentration
 120-160 percent sulfuric acid is known as Oleum and is
infused with sulfur trioxide
 Also called fuming sulfuric acid
 Highly concentrated acid fumes with high vapor
pressure (Sulfur Trioxide VP=0.57 atm)
 Corrosives without water are reactive
 Oleum fumes released into the air interact with the
water vapor to create a vapor cloud
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11. Corrosive Risk
 All corrosives present some form of risk
 pH of less than 2 and greater than 11 present significant
potential for skin contact injuries
 Low pH materials like oleum will cause immediate
burns
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 High pH materials like sodium hydroxide dissolve fats
and break down cellular membranes
 Corrosive in the eyes can cause immediate and
permanent damage
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 Eye contact should be avoided
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12. pH Detection
 pH paper is most common method of pH detection
 Commonly come on a roll with a pH range of 1-12 or 0-13
 More expensive test strips can provide more detailed pH
information
 pH paper can determine presence of corrosive vapors
in air
 Not necessary to wet pH to detect vapors
 pH paper can detect as low as 1 ppm anhydrous
ammonia
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13. pH Detection
 Some liquids cause
misleading readings with
pH paper
pH 4-8 most
likely neutral
 Use leading edge to
determine accurate pH
 Hydrocarbons typically
pH 4-8 most likely
Corrosive
will provide a false
positive 4 or 5 on pH
paper
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14. Summary
 Detection of pH is important to your health and
safety
 Detection will protect electronic instruments
 Corrosives are the second leading material
released during chemical accident
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