© 2012 delmar, cengage learning chapter 4 gases, vapors, particulates, and toxic metals
TRANSCRIPT
© 2012 Delmar, Cengage Learning
Chapter 4Gases, Vapors, Particulates,
and Toxic Metals
© 2012 Delmar, Cengage Learning
Physical Hazards
• A chemical that falls into one of the following categories: compressed gas, explosive, flammable gas, oxidizer, pyrophoric, or unstable.
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Asphyxiants
• Simple asphyxiant – gases that displace the oxygen content in the air. Inert gases.
• Chemical asphyxiant – Gases that prevent cells from using oxygen or prevent the blood from supplying oxygen.
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• Anesthetic gases – Have a numbing effect and will cause the loss of sensation and unconsciousness.
• Systemic poisons:1. Arsine – blood cells and liver
2. Benzene – bone marrow
3. Hydrogen sulfide – respiratory system
4. Mercury – nervous system, kidneys, glands
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Health Hazards• Carcinogens – are known cancer causers• Mutagen – a chemical that is suspected
to have the properties required to change or alter the genetic structure of a living cell.
• Teratogen – a substance that is suspected to have an adverse effect on the development of a human fetus.
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Bhopal – Union Carbide
• A large vapor cloud composed of methyl isocyanate (MIC) escaped.
• 1,400 people died.
• This was the first time in modern chemical manufacturing history an event had taken place near a populated area showing how vulnerable a community can be to CPI hazards.
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Figure 4-2 Flow Diagram of the Process that Caused the Disaster
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Bhopal Mistakes:• The vent gas scrubber and flare system
was undersized.• The refrigeration system was dismantled.• Faulty alarms and instrumentation.• A jumper line was installed.• Stainless steel was not used to save
money.
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Particulates
• Small liquid or solid particles dispersed through the air.
• Various concentrations will have differing effects.
• Coal dust caused Black Lung.
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Dust and Gases
• Any type of dust can be potentially dangerous if sufficient quantities are inhaled.
• Two types of respiratory protection programs: air purifying and air supplying.
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Dust explosions
• Occur when particle concentrations are detonated from a single spark.
• Almost anything will burn if broken down into small enough parts.
• Dust acts as fuel in Fire Triangle.
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Figure 4-5 Examples of Gaseous Hazards
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Figure 4-6 Harmful Effects of Toxic Metals
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• Metallic compounds can be as dangerous as the purer form if not more dangerous depending on how the chemical is introduced into the human system.
• Class D fires involve fires caused by metals. The proper fire extinguishers must be used for these types of fires.