1. The 8-hour time-weighted average limit set by the
Occupational Safety and Health Administration (OSHA) for carbon monoxide (CO)
is 50 ppm. The OSHA regulation at 29 C.F.R. §1910.1000(d) requires employers to
determine the cumulative exposure of workers to certain gases over an 8-hour
work shift using the formula below.
Where:
E = equivalent exposure for the work shift
C = concentration during any period of time in which the concentration remains
constant
T = duration of time in hours of the exposure
The regulation further stipulates that no
employee can be further exposed to the gas when the value of E exceeds the
8-hour time-weighted average limit set for the given substance. Using the
formula above, determine if the employer complied with this regulation if a
worker is exposed to CO concentrations throughout the workday as follows: 45
ppm for 3.25 hours; 75 ppm for 2.5 hours; 50 ppm for 1.5 hours and 60 ppm for
45 minutes. Explain CO poisoning and the interaction of CO with hemoglobin.
Please show
your exposure calculation, not just your calculated answer. Your
response must be at least 75 words in length.
2.
Ammonia is a colorless gas that is easily
recognized because of its pungent odor. Ammonia is often encountered as
anhydrous ammonia. Describe anhydrous ammonia and at least three of its
commercial uses. When there is a release, explain why emergency responders
should not apply water directly to the release of aqueous ammonia. Provide its
chemical reaction with water.
Your response must be at least 75 words in
length.
3.
In the biological treatment of wastewater,
microorganisms break down the organic matter, such as food, oil, and human
waste, in the wastewater and forms CO2 and
microbial biomass. When firefighters combat a fire near a wastewater treatment
plant where agricultural pesticides are involved, explain why the wastewater
treatment operators are notified. Also, explain why there are fewer inorganic
pesticides that are encountered today.
Your response must be at least 75 words in
length.