cpe615 tutorial 1
TRANSCRIPT
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7/27/2019 CPE615 Tutorial 1
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Faculty of ChemicalEngineeringUniversiti Teknologi MARA
Process Safety CPE615
TUTORIAL 1
1. By giving some examples, differentiate the following terms:
a) Safety and Health
b) Hazard and Risk
c) Incident and Accident
d) Root cause and Immediate cause of an accident
2. What is inherent safety? Give some examples of inherent safety approaches used in thechemical industry.
3. Using some examples, compare and contrast direct and indirect costs of accident.
4. The Occupational Safety and Health (Safety and Health Committee Regulations 1996 P.U.
(A) 616/96) is one of the regulations under the Occupational Safety and Health Act 1994.Explain how a safety and health committee can help improve safety and health performance
at a workplace.
5. The probit for death due to the exposure to Chemical A is given by
( )+= TCY 0.1ln69.327.19
Where C refers to the concentration in ppm and T is time interval in minute.
a) Determine the percentage of death if a group of 100 workers is exposed to 100 ppm ofChemical A for 30 minutes.
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Faculty of ChemicalEngineeringUniversiti Teknologi MARA
Process Safety CPE615
b) Estimate the duration of exposure to 20 ppm Chemical A that results in fatalities for
65% of the exposed population.
c) Estimate the exposure concentration in ppm that will result in fatalities for10% and 83%
of the exposed individuals if they exposed to Chemical A for 5 minutes.
6. Air contains 4 ppm of carbon tetrachloride and 25 ppm of 1,1-dichloroethane. Compute the
mixture TLV, and determine whether this value has been exceeded.
7. The TLV-TWA for Substance A is 150 ppm. A worker begins a work shift at 8.00 a.m. and
completes the shift at 5.00 p.m.
A one-hour lunch break is included between 12 noon and 1 p.m., where it can be assumed
that no exposure to the chemical occurs.
The concentration of Substance A in the work area is monitored from time to time and the
data are shown below:
Time Concentration (ppm)8.10 a.m. 1109.05 a.m. 130
10.07 a.m. 14311.20 a.m. 16212.12 p.m. 1421.17 p.m. 1572.03 p.m. 1593.13 p.m. 1654.01 p.m. 1535.00 p.m. 130
Has the worker exceeded the TLV specifications?.
8. A substance has a TLV-TWA of 200 ppm, a TLV-STEL of 250 ppm, and a TLV-C of 300 ppm.
The data in the following table were taken in a work area:
Time Concentration (ppm)
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Faculty of ChemicalEngineeringUniversiti Teknologi MARA
Process Safety CPE615
8.01 a.m. 1859.17 a.m. 240
10.05 a.m. 27011.22 a.m. 23012.08 p.m. 1901.06 p.m. 1502.05 p.m. 170
3.09 p.m. 1654.00 p.m. 1605.05 p.m. 130
A worker on an 8-hour shift is exposed to this toxic vapour. Is the exposure within
compliance? If not, what are the violations? Assume that the worker is at lunch between the
hours of 12 noon to 1 p.m., and is not exposed to the chemical during that time.
9. Hazard identification is a crucial step in managing safety and health of a workplace. Give
three (3) reasons why hazards need to be identified and explain the sources of information inthe identification of hazards in a chemical plant