study guide

1

 Instruments for IAQ studies

 Thermometer

 Anemometer

 Psychrometer

 Smoke tubes

 IAQ multi-function instrument

 Evaluation of makeup air

 Volume of makeup air (Voa)

 Percent of makeup air (%OA)

 Microbial contamination

 Legionnaire’s disease

 Hanta virus

 Histoplasmosis

 Chemical contamination

 Radon

 Asbestos

EHST 3700/3701:

Industrial Hygiene

 To discuss the hierarchy of control strategies

 To explain the basic principles of dilution

ventilation

 To explain the basic principles of local exhaust

ventilation

 To discuss the evaluation of ventilation system

performance

 To discuss regulations and other standards

about ventilation system design and

performance

 To calculate the amount of dilution ventilation

required to reduce contaminants to acceptable

levels

 Hierarchy of control strategies

 Local exhaust ventilation systems

 Dilution ventilation for contaminant

control Health Hazards Beyond

Acceptable Exposure

DISEASE

C O

N T

R O

L S

Health Hazards

2

Engineering Controls

Administrative Controls

Personal Protective Equipment

 Minimize employee exposure by either

 Reducing or removing the hazard at the

source

 Preventing the release of the hazard

into the air

 Isolating the worker from the hazard

Dip Tank

Elimination

Substitution

Process change

Automation

Isolation and enclosure

Ventilation

 Removing the hazard completely

 Elimination of a hazardous material,

equipment and process (if possible)

 Substituting a less hazardous material for

a more hazardous one

 Blasting: sand  walnut shells

 Solvent usage: fluorinated or chlorinated hydrocarbons  hydrochlorofluorcarbons

 Paint thinners: benzene  toluene

 White paint: white lead  titanium dioxide

 Asbestos  calcium silicates

 Gauges: mercury  oil

 Cleaning: solvents  soap and water

3

 CAUTION! Always consider the resulting hazard.

Acetone Toluene

 Less toxic material

 Increases emissions

(lower boiling point)

 Increases the fire hazard

(lower flash point)

 More toxic material

 Higher boiling point

 Higher flash point

 Attempts to replace more hazardous

equipment or processes with less

hazardous approaches

 Paint spraying  paint dipping

 Welding  bolting

Demolition of Building Structure under Wet Method

 Use of low-vibration tools

 Includes gas-powered chain-saw, string

trimmers, edgers, other gardening and

grounds keeping tools

 Automobile body seams: lead solder 

polyester resin sealants

 High-speed rotary grinder  slow-speed

oscillating grinders

 Handwashing of parts  cooling-coil

vapor degreasing tanks

 Open batch processes  continuous

closed processes

4

 Separating man from hazardous operations, processes, equipment, or environments by time and space

 To prevent or minimize contact

 Isolation techniques

 Storage of hazardous materials

 Isolating equipment

 Isolating workers

 Enclosing a sandblasting

operation in an airtight

housing

 Enclosing crane

operators in an air-

supplied cab

 Storage of hazardous

materials

 Use of ventilated storage

cabinets for chemicals

 Isolating workers

 Use of closed control

rooms

 Use of isolation booths

 Use of supplied-air

islands

 Isolation by time

 Foundry shake-out

scheduled during the

evening when most

employees have left the

workplace

 Maintenance performed

during regular shutdown

periods when production

employees are not present

Non-enclosed Machine Enclosed Machine

 Hazards Isolated

 Noisy process or machine

 Dusty process

 Hot process

 Vibrating machine

 Biological agents in glove boxes

5

 Elimination of the need for manual work

 Examples

 Use of a robot to load boxes

 Use of palletizer to place cartons on a

pallet

 “Mechanization” - a machine does part of

the job but an operator is still present

 Use of a bar code scanner instead of

keying information

 Widely used and time-tested approach to

emission and exposure control

 Types

General exhaust

ventilation (GEV)

Local exhaust

ventilation (LEV)

Process Slot

 Designed to contain, control, or capture

emissions at or near their sources

 Attempts to eliminate emissions to the

workroom air

 Provides sufficiently rapid turnover of the

workplace air to achieve effective dilution of

airborne contaminants

 Allow emissions to occur and dilute

contaminants to some acceptable

concentration before the contaminated air

reaches the breathing zone

 Generally the most expensive method of

control

 May interfere with work processes

 Involves changes in organization of people

 Place at least part of the burden of

responsibility on the worker

 Often effectively used in conjunction with

or in addition to engineering controls

6

 Job rotation and job enrichment

 Reduction of exposure time

 Good work practices

 Good housekeeping

 Regular preventive maintenance

 Regular monitoring and inspection

 Training and education of employees

 Assigning workers to areas with less

exposure to chemicals

 Assigning workers to less stressful areas

to relieve muscles

 Good personal hygiene practices

 Work breaks

 Following standard operating procedures

 Proper manual lifting

 Avoiding shortcuts

 Proper disposal of hazardous materials

 Lockout/Tagout

 Proper materials handling and storage

 Use of proper tools and equipment

Heat exposure

Noise exposure

Vibration exposure

Repetitive motion

Static postures

 Settled particulate materials and chemical

spills  secondary emission sources

 Required in some OSHA standards (i.e.

standard for inorganic lead)

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10030

7

 Dust removal and control

 Wet cleaning method

 Vacuum system

 NOT sweeping and blowing

 Spilled liquids

 Cleaned up before evaporation

Prevention of emissions from leaks

from seals

Regular lubrication of machines

Air monitoring in chemical storage

areas

Air monitoring inside confined spaces

Noise monitoring

Heat stress monitoring

Illumination monitoring

 Conditioning period for new or

reassigned employees

 Recognition of health and safety

hazards (hazard communication)

 Work techniques and procedures

that reduce health and safety

hazards

 Involves the behavioral component

(management, workers)

 May interfere with work process

 Considered “last resort” type of exposure

control

 Used only

 When engineering or administrative controls are

not feasible

 While controls are being instituted

 Existing controls are not sufficient

 Reinforce other controls instituted

8

 Acts as barrier but does not eliminate

hazards

 Should not substitute feasible administrative

and engineering controls

 Hazards

 Body part protected

 Head

 Eyes

 Face

 Ears

 Body

 Hands and arms

 Feet and legs

 Respiratory system

Ears Eyes Face Head

Ear plugs

Ear muffs

Safety glasses

Spectacles

Goggles

Face shields

Visors

Hoods

Hard hats

Hair caps

Helmets

Full-body suits

Lab coats

Topcoat

Apron

Smocks

Jackets, parka

Vest

Pants

Coveralls

Safety belts

Harness

Gloves

Mittens

Gauntlets

Finger cots

Armlets

Hand pads

Sleeve protector

Finger guards

Wristlets

Wrist closure

Wire-mesh gloves

Safety shoes

Boots

Leggings

Shoe covers

Knee pads

Toe guards

Shin guards

Spats

Metatarsal

guards

Air purifying

Air suppling

SCBA

Engineering

Administrative

PPE

Engineering

Administrative

PPE

Engineering

Administrative

PPE

9

Source Air Path Receiver

1. Substitution with a

less harmful

material

2. Change of process

3. Enclosure of

process

4. Isolation of process

5. Wet methods

6. Local exhaust

ventilation

7. Adequate

maintenance

program

1. Housekeeping

2. General exhaust

ventilation

3. Dilution ventilation

4. Increase distance

between source and

receiver

5. Continuous area

monitoring

6. Adequate

maintenance

program

1. Training and

education

2. Rotation of workers

3. Enclosure of worker

4. Personal monitoring

devices

5. Personal protective

devices

6. Adequate

maintenance

program

Dip Tank

 Control strategies for workplace hazards are

prioritized as follows: engineering controls,

administrative controls, and personal

protective equipment.

 Engineering controls include elimination,

substitution, automation, isolation and

ventilation.

 Administrative controls include job rotation

and enrichment, exposure time reduction,

proper work practices, and worker training.

 PPE includes ear, eyes and head protection,

anti-vibration gloves, protective clothing,

and respirators.