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