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ChemistryChemistry

Instructional GoalInstructional Goal: upon : upon completion of this topic, the completion of this topic, the student will have a better student will have a better understanding of potentially understanding of potentially hazardous situations involving hazardous situations involving corrosives, solvents, oxidizers, corrosives, solvents, oxidizers, and reactive chemicals.and reactive chemicals.

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Chemical AwarenessChemical Awareness

Hazardous substances are used in Hazardous substances are used in business and industry. A basic business and industry. A basic knowledge of chemical hazard knowledge of chemical hazard classes, chemical terms, and a classes, chemical terms, and a basic chemical hazard awareness basic chemical hazard awareness is required by OSHA.is required by OSHA.

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HAZARD COMMUNICATION HAZARD COMMUNICATION STANDARD 29 CFR STANDARD 29 CFR 1910.12001910.1200

The employer’s Haz Com program must The employer’s Haz Com program must include:include:

Conduct a chemical inventory.Conduct a chemical inventory. Obtain and file MSDSs for all chemicals.Obtain and file MSDSs for all chemicals. Label all containers.Label all containers. Train employees about the hazards.Train employees about the hazards. The Haz Com program must be written The Haz Com program must be written

and available to employees.and available to employees.

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Material Data Safety Material Data Safety SheetSheet

Product ID and manufacturer nameProduct ID and manufacturer name Hazardous ingredientsHazardous ingredients Physical / chemical characteristicsPhysical / chemical characteristics Fire and explosion hazard dataFire and explosion hazard data Reactivity dataReactivity data Health hazard dataHealth hazard data Safe handling and useSafe handling and use Control measuresControl measures

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LABELINGLABELING

Chemical identity Chemical identity and/or trade name of and/or trade name of the hazardous material.the hazardous material.

Hazard warning(s).Hazard warning(s).

Name and address of Name and address of chemical manufacturer.chemical manufacturer.

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LABELING

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2W

NFPA 704

HMIS

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Chemical AwarenessChemical Awareness

Chemical names and terms can Chemical names and terms can be very confusing and be very confusing and misleading, but can alert a misleading, but can alert a worker to a chemical that has a worker to a chemical that has a potential to harm.potential to harm.

Chemical names and hazards Chemical names and hazards must be verified with an MSDS must be verified with an MSDS or other such sourceor other such source

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Chemical Names with Chemical Names with Potential HazardPotential Hazard

aluminumaluminum bariumbarium chlorinechlorine coppercopper leadlead mercurymercury

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Word FragmentsWord Fragments

-ite -ite -ate-ate nitro-nitro- acryl-acryl- chloro-chloro- isocyan-isocyan-

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Corrosive Class ChemicalsCorrosive Class Chemicals

Corrosives are the second most Corrosives are the second most commonly used and transported commonly used and transported group of hazardous materials.group of hazardous materials.

A corrosive material is A corrosive material is defined as “any liquid that defined as “any liquid that has a severe corrosion rate has a severe corrosion rate on steel”.on steel”.

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Corrosive Class ChemicalsCorrosive Class Chemicals

bases bases (caustics)(caustics)

acids (corrosives)acids (corrosives)

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CorrosivesCorrosives

CORROSIVES

Acids Bases (caustic)

HCl NaOH

When dissolved in water

HCl H + Cl+ NaOH Na + OH+ --

Hydrogen ion (H ) Hydroxide ion (OH )+ -

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Chemical AwarenessChemical Awareness

pH range is from 0 - 14pH range is from 0 - 14

AcidsAcids• low pH numberlow pH number• high concentration of (Hhigh concentration of (H++)) ionsions

BasesBases• high pH numberhigh pH number• low concentration of (Hlow concentration of (H+ + )) ionsions

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pH ScalepH Scale

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

A cid BaseNeutral

Increasing strength ( H ) Increasing strength (OH )+_

pH Scale

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Acid-Base NeutralizationAcid-Base Neutralization

HCl + NaOH H + Cl + Na + OH+ - + -

NEUTRALIZATION

Mixing an Acid with a Base

H + Cl + Na + OH NaCl + HOH + Energy+ - + -

Acid + Base Salt + Water + Heat

The energy or heat may be sufficient tocause a violent reaction releasing toxicvapors and/or irritating gases.

StrongStrong vs WeakWeak

Strength of a Corrosive: is the % dissociation of the corrosive when mixed with water.

HClHCl 100%100% H & Cl+ -

(StrongStrong: 100% dissociation)

CHCH33 COOH COOH 2%2% H & CH3COO + 98%98% CH3COOH + -

(WeakWeak: only 2% dissociation)

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CONCENTRATIONCONCENTRATION

The amount of material in a given volume of water.

The larger the number before the term the more concentrated the solution.

1M soln > 0.1M soln

• Molar• Percent

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Strength vs ConcentrationStrength vs Concentration

strong vs weakstrong vs weak• amount of dissociationamount of dissociation

concentrated vs diluteconcentrated vs dilute• amount of additional amount of additional

solvent (Hsolvent (H22O)O)

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Corrosive HazardsCorrosive Hazards

destroy living tissuedestroy living tissue chemical burn is 9 times more chemical burn is 9 times more

damaging than a thermal burndamaging than a thermal burn extent of injury from corrosive extent of injury from corrosive

exposure:exposure:• concentration of corrosiveconcentration of corrosive• quantity of corrosivequantity of corrosive• body area affectedbody area affected• duration of contactduration of contact

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Corrosive HazardsCorrosive Hazards

Vapor - far reachingVapor - far reaching• InhalationInhalation

LiquidLiquid• skin/eye contact - splashskin/eye contact - splash

SolidSolid• Inhalation of dustInhalation of dust• skin/eye contactskin/eye contact

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Protective MeasuresProtective Measures

common exposures and protectioncommon exposures and protection• hands - gloveshands - gloves• nose, throat, airway - respiratornose, throat, airway - respirator• feet - closed toe shoesfeet - closed toe shoes• face - faceshieldface - faceshield• eyes - goggles or glasses with side-eyes - goggles or glasses with side-

shieldsshields

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Treatment for Skin Treatment for Skin ExposureExposure

flush with water:flush with water:• physically remove corrosivephysically remove corrosive• dilution of corrosivedilution of corrosive

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Hazardous MixturesHazardous Mixtures

Corrosives and PoisonsCorrosives and Poisons• release toxic gasesrelease toxic gases

Corrosives and Ignitable MaterialsCorrosives and Ignitable Materials• many possible reactions depending on chemicalsmany possible reactions depending on chemicals• some corrosion are oxidizerssome corrosion are oxidizers

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Hazardous MixturesHazardous Mixtures

Corrosives and WaterCorrosives and Water• violent reactionviolent reaction• generation of heatgeneration of heat• production of a vapor cloudproduction of a vapor cloud• over-pressurization of containerover-pressurization of container

Corrosives and MetalCorrosives and Metal• destruction of metal destruction of metal

Never store corrosives in a metal container!Never store corrosives in a metal container!

• production of hydrogen gasproduction of hydrogen gas

HOT

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Polychlorinated Biphenyls Polychlorinated Biphenyls - PCBs- PCBs

found in plants, found in plants, animals, and soil animals, and soil around the worldaround the world

transported throughout transported throughout the biosphere by the biosphere by several pathwaysseveral pathways

suspected human suspected human carcinogencarcinogen

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SolventsSolvents

halogenated solventshalogenated solvents– hydrocarbon solvents that contain one or more hydrocarbon solvents that contain one or more

halogen atoms (Cl, F, or Br) attached to the halogen atoms (Cl, F, or Br) attached to the hydrocarbon molecule. hydrocarbon molecule.

flammable solvents flammable solvents • A hydrocarbon solvent having a flashpoint below 100 A hydrocarbon solvent having a flashpoint below 100

deg. F. (37.8 deg. C.)deg. F. (37.8 deg. C.)

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Solvent HazardsSolvent Hazards

Primary HazardPrimary Hazard• Chemical Physical Chemical Physical

hazardhazard

Secondary hazardSecondary hazard• Chemical Health Chemical Health

hazardhazard

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Fire and ExplosionFire and Explosion

OxidizerOxidizer

FuelFuel

Ignition sourceIgnition source

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Acute Health HazardsAcute Health Hazards

InhalationInhalation• NauseaNausea• Headaches and drowsinessHeadaches and drowsiness• Irritation of mucous membranes of the Irritation of mucous membranes of the

respiratory passagerespiratory passage• Muscular weaknessMuscular weakness• Loss of coordinationLoss of coordination• Disorientation and confusionDisorientation and confusion• Unconsciousness and sometimes deathUnconsciousness and sometimes death

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Acute Health HazardsAcute Health Hazards

• Skin/eye contactSkin/eye contact Removal of skin oils resulting in Removal of skin oils resulting in

irritationirritation Cracking and Rashes on the skinCracking and Rashes on the skin DermatitisDermatitis Burning and Irritation of eyesBurning and Irritation of eyes

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Do’s for SolventsDo’s for Solvents

Read the container label and MSDS Read the container label and MSDS before you use the chemical. before you use the chemical.

Keep the work area clean. Fewer spills Keep the work area clean. Fewer spills happen in clean work areas.happen in clean work areas.

Use protective clothing and equipment when Use protective clothing and equipment when

• operating procedures call for themoperating procedures call for them• MSDS recommends it MSDS recommends it • over-exposures are detected or expectedover-exposures are detected or expected

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Do’s for SolventsDo’s for Solvents

Use only approved and labeled Use only approved and labeled containers for storing and transporting containers for storing and transporting solvents.solvents.

Make sure there is proper ventilation Make sure there is proper ventilation when using solvents.when using solvents.

Keep flammables away from heat and Keep flammables away from heat and ignition sources.ignition sources.

Check that containers and hoses are in Check that containers and hoses are in good working condition.good working condition.

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Don’ts for SolventsDon’ts for Solvents

DON'TDON'T leave containers open when not in leave containers open when not in use.use.

DON'TDON'T siphon by mouth.siphon by mouth.

DON'TDON'T depend on a "funny smell" to detect depend on a "funny smell" to detect hazardous gases in the air - some are hazardous gases in the air - some are odorless.odorless.

DON'T DON'T breathe gases produced from breathe gases produced from chemical reactions.chemical reactions.

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DON'TDON'T mix solvents - unless instructed to; mix solvents - unless instructed to; follow instructions exactly and double checkfollow instructions exactly and double check

DON'TDON'T smoke, eat or drink around smoke, eat or drink around hazardous substances.hazardous substances.

DON'TDON'T wear contact lenses around toxic wear contact lenses around toxic vapors.vapors.

DON'TDON'T track hazardous materials from one track hazardous materials from one location to the next.location to the next.

Don’ts for SolventsDon’ts for Solvents

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Don’ts for SolventsDon’ts for Solvents

DON'TDON'T store hazardous chemicals store hazardous chemicals next to each other without next to each other without checking the MSDS for possible checking the MSDS for possible reactions.reactions.

DON'TDON'T work by yourself; have work by yourself; have someone nearby who knows where someone nearby who knows where you are and what you're doing at you are and what you're doing at all times.all times.

DON'TDON'T cut corners on hazardous cut corners on hazardous substance handling procedures.substance handling procedures.

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Treatment for Solvent Treatment for Solvent ExposureExposure

15 minute flush at a minimum15 minute flush at a minimum

wash skin with soap and waterwash skin with soap and water

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OxidizersOxidizers

oxidizing elements oxidizing elements • OO22, Cl, Cl22

oxysaltsoxysalts• NONO33, ClO, ClO33

inorganic peroxidesinorganic peroxides certain acidscertain acids organic peroxidesorganic peroxides

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Hazards of OxidizersHazards of Oxidizers

intensify intensify combustioncombustion

spontaneous spontaneous ignitionignition

explosionexplosion produce toxic produce toxic

fumesfumes gaseous oxidizersgaseous oxidizers

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Water Reactive MetalsWater Reactive Metals

lithiumlithium sodiumsodium potassiumpotassium berylliumberyllium magnesiummagnesium calciumcalcium

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Unstable MaterialsUnstable Materials

Alkali Metals - Na, K, LiAlkali Metals - Na, K, Li Organic peroxides - acetyl peroxide, MEK Organic peroxides - acetyl peroxide, MEK

peroxideperoxide Monomers - styrene, vinyl chlorideMonomers - styrene, vinyl chloride

Unstable is defined as any material that will spontaneously decompose, polymerize, or self-react under conditions of shock, temperature, or pressure

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ExplosivesExplosives

igniterigniter primerprimer detonatordetonator booster chargebooster charge main chargemain charge

Main Charge

Booster Charge

DetonatorPrimer

Igniter