Technical issues - an introduction to occupational

hygiene

Profession concerned with identification, evaluation and control of occupational hazards

IH Program Components

• Hazard identification

• Risk evaluation relative to hazard exposure

• Hazard monitoring

• Control plan development

• Evaluation of effectiveness of controls

Types of hazards evaluated

• chemical

• physical

• biological

Chemical Hazards

• Compressed gases• Flammable and Combustible

Materials• Oxidizers• Poisonous or infectious

materials– causing immediate and serious toxic

effects– causing other toxic effects– biohazardous infectious material

• Corrosive material• Dangerously reactive material

Physical hazards

• ionizing radiation

• non-ionizing radiation

• heat

• cold

• pressure

• vibration

• noise

• ergonomics

• “indoor air quality”

Biological Hazards

• plants

• animals

• microorganisms

• the products of the above

Exposure Routes

• Inhalation - hazards producing oxygen deficiency (asphyxiants), hazards containing toxic contaminants

• Skin absorption - hazards gaining entry through skin, mucous membranes, eyes, hair follicles

• Ingestion - hazards swallowed by eating drinking smoking in contaminated areas

IH Monitoring

• Observation

• Measurement

• Judgment to recognize potential hazards

• Evaluate protection

Chemical exposure monitoring

• Area Monitoring

• Personal Sampling

• Biological Monitoring

Considerations in devising strategy

• How many people to sample

• Which people to sample

• When to sample

• How long to sample

Controls - Two approaches

• Engineering, Administrative,

Personal Protective Equipment

• At the source, Along the path,

At the worker

Examples

• At the Source - substitution, mechanized process, isolated/enclosed process

• Along the path - local exhaust ventilation, general ventilation, housekeeping

• At the worker - education, enclose worker, respirators, gloves, protective clothing, locker rooms, eye wash, shower, etc...

Examples

• Engineering - local exhaust ventilation, substitution, mechanize process, isolate worker

• Administrative - worker education, safe work rules, reduce exposure time

• PPE - goggles, gloves, respirators, etc...

Industrial Hygiene Problem Solving

• Why is the evaluation being requested?

• Are there physical symptoms/complaints of over-exposure?– How many workers of total

affected?– List symptoms– Note date of commencement of

symptoms– Note locations of symptomatic

workers

Industrial Hygiene Problem Solving

• Describe process

• List potential contaminants (chemicals used in process, by-products, end-products, etc..)

• List acute/chronic symptoms associated with each chemical

• Identify control measures presently in use

Industrial Hygiene Problem Solving

• Note TLV-TWA, TLV-STEL, TLV-C of each contaminant

• Correlate symptoms with contaminants to determine which to sample for

• Determine sampling strategy - whom to sample, how long, which method, when to sample; types of sampling (area, personal, biological); direct reading vs. indirect;

Industrial Hygiene Problem Solving

• Conduct sampling if required and compare results with standards

• Make recommendations using options where possible, identifying the hierarchy of controls, and, if required, costs