Industrial Hygiene An Introduction For Chemical Engineers Goal

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Industrial Hygiene An Introduction For Chemical Engineers

Industrial Hygiene An Introduction For Chemical Engineers

Goal of Industrial Hygiene w Worker safety and well-being n Anticipation n Recognition n

Goal of Industrial Hygiene w Worker safety and well-being n Anticipation n Recognition n n Evaluation Control

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Chemical Hazards w w w Irritants Asphyxiants CNS Agents Specific organ agents Genetic activity

Chemical Hazards w w w Irritants Asphyxiants CNS Agents Specific organ agents Genetic activity Acute versus Chronic

Irritants w Respiratory w Skin w Eye

Irritants w Respiratory w Skin w Eye

Irritants w Primary/Secondary n n Primary – at source of contact Secondary – travels

Irritants w Primary/Secondary n n Primary – at source of contact Secondary – travels through blood to another area w Reversible/Irreversible w Sensitization n Irritant that has a delayed reaction on subsequent exposure

Asphyxiants w Simple Asphyxiants n n N 2 CO 2 He CH 4 w

Asphyxiants w Simple Asphyxiants n n N 2 CO 2 He CH 4 w Dilute air so oxygen content is low w Chemical Asphyxiants n n n CO HCN H 2 S w Interact at cellular level to inhibit oxygen uptake.

Central Nervous System Depressants w Narcotics w Anesthetics w Depressants

Central Nervous System Depressants w Narcotics w Anesthetics w Depressants

CNS Depressants w Aliphatic Hydrocarbons n n n Increased chain length enhances effect Addition

CNS Depressants w Aliphatic Hydrocarbons n n n Increased chain length enhances effect Addition of an alcohol group (i. e. ethanol) Addition of a halide group enhances the effect

Specific Organ Attack w May be reversible or irreversible n n n Blood -

Specific Organ Attack w May be reversible or irreversible n n n Blood - Hemotoxic Liver – Hepatotoxic Lungs – Pulmonotoxic Kidneys – Nephrotoxic Skin – Dermatotoxic Nerves & Brain - Neurotoxic

Genetic Activity w Typically is irreversible n n Causes cancer – Carcinogen Causes chromosome

Genetic Activity w Typically is irreversible n n Causes cancer – Carcinogen Causes chromosome damage – Mutagen Causes birth defects – Teratogen Causes damage to reproductive system Reproductive Hazard

Anticipation of Chemical Hazards w Consider the following: n n n Raw materials Intermediates

Anticipation of Chemical Hazards w Consider the following: n n n Raw materials Intermediates formed Final products Disposal of used products Maintenance materials w “Cradle to Grave” thought process

Anticipation of Chemical Hazards w Occupational Safety and Health Administration (OSHA) has established Permissible

Anticipation of Chemical Hazards w Occupational Safety and Health Administration (OSHA) has established Permissible Exposure limits n They are defined in time weighted average, TWA, for most working conditions. Short Term Exposure Limits, STEL, for 15 minute exposure. Ceiling, C, for maximum allowable concentration. w American Council of Government Industrial Hygienists (ACGIH) has established Threshold Limit Values, TLV.

Anticipation of Chemical Hazards w Material Safety Data Sheets, MSDS

Anticipation of Chemical Hazards w Material Safety Data Sheets, MSDS

Recognition of Chemical Hazards w Odors n Not all agents have detectable odor w

Recognition of Chemical Hazards w Odors n Not all agents have detectable odor w Frequent headaches w Dermatitis w Drowsiness w Personality changes w Clusters of problems

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Physical Hazards w Dusts and Fibers w Noise w Corrosives w Temperature Extremes w

Physical Hazards w Dusts and Fibers w Noise w Corrosives w Temperature Extremes w Ionizing Radiation w Non-Ionizing Radiation

Dusts and Fibers w Concerned about particle size and penetration into pulmonary track n

Dusts and Fibers w Concerned about particle size and penetration into pulmonary track n n n D > 0. 5 micron – does not reach lungs (but may ingest) 0. 2 < D < 0. 5 micron – respirable and gets stuck in lungs D < 0. 2 micron – are exhaled

Noise Hazard Recognition w Need to shout w Ringing sensation w Degraded hearing after

Noise Hazard Recognition w Need to shout w Ringing sensation w Degraded hearing after work w Auditory testing

Noise Hazard w Sound level measurement L = 10 * Log (I/I 0)2 L

Noise Hazard w Sound level measurement L = 10 * Log (I/I 0)2 L = Sound intensity, decibels (d. B) P = Sound pressure, rms (Pa) I 0 = Reference sound pressure, rms (20 Pa)

Typical Noise Sources Source Rocket Jet Engine Rock Band Power Lawn Mower Factory Noisy

Typical Noise Sources Source Rocket Jet Engine Rock Band Power Lawn Mower Factory Noisy Office Conversation Quite Room Whisper Sound Level (d. B) 195 160 115 95 90 80 65 40 20

OSHA Sound Level PEL’s Sound Level (d. B) < 90 90 95 100 105

OSHA Sound Level PEL’s Sound Level (d. B) < 90 90 95 100 105 110 115 > 115 Exposure Time Limit (hr) No Limit 8 4 2 1 ½ ¼ 0

Noise Control w Enclose equipment w Enclose operator w Slower rotational speed w Intake/Exhaust

Noise Control w Enclose equipment w Enclose operator w Slower rotational speed w Intake/Exhaust mufflers w Padded mountings

Corrosive Hazards w Usually concerned with the affect of corrosives on process equipment w

Corrosive Hazards w Usually concerned with the affect of corrosives on process equipment w Concern for contact of workers with corrosives n Usually involves necrosis, the death of local tissue due to contact of agent

Temperature Extremes w Heat Stress n n Heat Stroke Heat Exhaustion w Cold Stress

Temperature Extremes w Heat Stress n n Heat Stroke Heat Exhaustion w Cold Stress n n Frostbite Hypothermia

Heat Stress w Body’s Energy Balance w External Conditions n n Metabolic rate Radiation

Heat Stress w Body’s Energy Balance w External Conditions n n Metabolic rate Radiation Convection Sweating n n Temperature Humidity Air movement Radiation In a typical healthy individual the internal core body temperature may rise as much as 3°C during heat stress

Cold Stress w Less Common in Industrial Situations n n n Cold climates Refrigerated

Cold Stress w Less Common in Industrial Situations n n n Cold climates Refrigerated space Wind chill w Responses to Cold Stress n n n Body core temperature is typically 37°C Shivering when body Tc < 36°C Lose Consciousness at Tc < 34°C

Temperature Stress Control w Hot Stress n n n Air movement Periodic rest Remove

Temperature Stress Control w Hot Stress n n n Air movement Periodic rest Remove to cooler location w Cold Stress n n Limit exposure time Protective clothing

Ionizing Radiation w Physical damage to cells w Possible genetic damage w Types of

Ionizing Radiation w Physical damage to cells w Possible genetic damage w Types of Radiation n n Alpha – emitted from nuclei of radioactive particles Beta – similar to but with more penetrating (~ 1 cm) X-ray – produced from high speed electrons striking material Gamma – originates from nucleus, produces burns Neutrons – emitted from disintegration of isotopes, very penetrating

Common Units to Measure Radiation w Rad – the unit of absorbed dose of

Common Units to Measure Radiation w Rad – the unit of absorbed dose of ionizing radiation equal to the absorption of 100 ergs/g w Roentgen – exposure to x-rays or gamma rays equal to absorption in 1 cm 3 of air to produce 1 electrostatic unit of charge w Rem – the dosage of ionizing radiation that will cause the same biological effect as 1 rad of x-, gamma or beta w Curie – the rate at which radioactive material emits particles, 3. 7 x 1010 disintegrations per second

Protection from Ionizing Radiation w Alpha, Beta - Little protection required w X-ray, Gamma

Protection from Ionizing Radiation w Alpha, Beta - Little protection required w X-ray, Gamma - w Neutrons Special shielding techniques - Extensive high density shielding

Non-Ionizing Radiation w Low frequency - ~ 3 m wavelength w Microwaves - 3

Non-Ionizing Radiation w Low frequency - ~ 3 m wavelength w Microwaves - 3 m to 3 mm w Infrared - 3 mm to 750 nm w Visible light - 750 nm to 400 nm

Non-Ionizing Radiation w Ultraviolet Radiation n UV-A l n n Harmful only to eyes,

Non-Ionizing Radiation w Ultraviolet Radiation n UV-A l n n Harmful only to eyes, causes sun tan UV-B l 320 to 280 nm Causes skin damage (sun burn), source arc welding UV-C l 400 to 320 nm 280 to 220 nm Severe damage, source germicidal lamps

Laser Light w Especially dangerous for eyes w Retinal burns w Corneal burns

Laser Light w Especially dangerous for eyes w Retinal burns w Corneal burns

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Ergonomic Hazards w Physiological Hazards n n Awkward movements Muscle strain w Psychological Hazards

Ergonomic Hazards w Physiological Hazards n n Awkward movements Muscle strain w Psychological Hazards n n n Boredom Concentrated attention Simulated inputs

Ergonomic Hazards w Increasing emphasis due to repetitive nature of some industrial manufacturing jobs.

Ergonomic Hazards w Increasing emphasis due to repetitive nature of some industrial manufacturing jobs. w Also with more operators working at computers or workstations there are ergonomic concerns.

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Workplace Hazards w Chemical w Physical w Ergonomic w Biological

Biological Hazards w Pathogenic organisms n Five levels of classification l l n n

Biological Hazards w Pathogenic organisms n Five levels of classification l l n n 1 least dangerous 5 most dangerous Pathogenic organisms are typically not found in a chemical processing facility Possible biological hazards in an industrial setting l l AIDS Hepatitis B

Biological Hazards w Industries with possible biological hazards n n Pharmaceutical Manufacturing Food processing

Biological Hazards w Industries with possible biological hazards n n Pharmaceutical Manufacturing Food processing or agricultural products w Typically hazards are well contained

Chemical Engineer’s Responsibility w Be aware of industrial hazards and possible effects. w Design

Chemical Engineer’s Responsibility w Be aware of industrial hazards and possible effects. w Design inherently safer systems that minimize worker exposure to hazards. w As a manager encourage proper safety procedures and good housekeeping to minimize employees exposure to hazardous situations.