Ch. 22 – Climate AREAS OF INTEREST: Comfort Stress Heat stress Cold stress Air volume and quality amount contaminants ventilation ISE 311 - 21
Comfort Factors For standard conditions Individual adjustments _____________________________________________ For standard conditions _____________________ Individual adjustments ______________________ Adjustments for nonstandard conditions _____________________ ISE 311 - 21
Heat Stress Effects on performance and health _____________________________________________ Setting environmental limits Reducing heat stress Design for comfort because ‘ordinary’ workers (not highly motivated) work less efficiently in hot environments For health, using multiple criteria is better than a single, but if a single criterion is needed, use body core temp. WBGT – wet bulb globe temperature. See fig. 25.7, pg. 496 heat balance equation – see pg. 496 ISE 311 - 21
Heat Transfer Radiant Convective Evaporative _____________________________________________ Convective Evaporative heat transfer – pp. 446-448 ISE 311 - 21
Cold Stress Cold causes discomfort, reduced mental performance and dexterity, pain, loss of extremities, and death _____________________________________________ Environmental Limits Protection Other Factors in Cold Stress ISE 311 - 21
Air Volume and Quality Volume of air required is proportional to local contaminants. Usually not a problem in office buildings, but … _______________________________________________ For forced-air heating and cooling, ventilation volume may be determined by room temperature. ASHRAE (American Society for Heating, Refrigeration, and Air conditioning Engineers) provides recommendations for air volume & humidity based on conditions (work level, CO2 levels, odors, smoking, etc.) This is discussed in detail in your text (pg. 452-453, esp. box 22.2) ISE 311 - 21
Ch. 23 – Chemical environment (a.k.a., toxicology) Deals with long-term effects of foreign chemicals on the body. Chemicals affect the body with doses producing a response. Controls can be engineered, administration, or personal protection. ISE 311 - 21
Effects of Poisons Effects may be permanent or ________ Threshold limit values are based on ___________. Response may _____ the dose by __________. Workers tend to ignore hazards with ___________ Financial benefits accrue to _________, heath costs to __________. ___________ cause defects in fetal development. TLV approach considers humans to be ________________. ISE 311 - 21
Dose/Response Chemicals can be detected in extremely low concentrations. The problem is to define “excess.” Poisoning depends on _____________________ The Leaky Bucket ISE 311 - 21
Poison Routes To enter the body, a poison must _________________ Poisons may be characterized by ____________________________________ The most important entrance points are _________________. ISE 311 - 21
Entry points Skin Mouth Lungs in general, __________________________________________ dermatitis Mouth Lungs ISE 311 - 21
Poison Interior targets Elimination Threshold limit values (TLV) __________________________________________ Elimination Threshold limit values (TLV) ISE 311 - 21
Example of TLV Calculation Assume worker exposed to acetone for 4 h at 500 ppm, 2 h at 750 ppm, 2 h at 1500 ppm. TWA = ________________________________ Is this acceptable? 812 > 750, so the exposure is unacceptable. ISE 311 - 21
Controlling Exposure Engineering Controls: __________________________________________ Personal Protective Equipment Administrative controls: ISE 311 - 21