In a machine shop a worker is exposed to the following levels of noise:
89 dBA for 3 hours
97 dBA for 1 hour
87 dBA for 2 hours
(6 hours total)
In a machine shop a worker is exposed to the following levels of noise:
89 dBA for 3 hours
97 dBA for 1 hour
87 dBA for 2 hours
(6 hours total)
What is the total noise dose for 89 dBA (3h), 97 dBA (1h), and 87 dBA (2h)?
2.1
Is the worker overexposed in Case Study One?
Yes, but just over the allowed exposure.
Case Study Two
A local exhaust ventilation system requires 2.5 m/s velocity to contain emissions from a grinding process. The enclosing hood opening is 1 m high and 1.5 m wide. The round duct is 30 cm in diameter.
Case Study Two
A local exhaust ventilation system requires 2.5 m/s velocity to contain emissions from a grinding process. The enclosing hood opening is 1 m high and 1.5 m wide. The round duct is 30 cm in diameter.
What volumetric flow rate (m³/s) is required to generate 2.5 m/s face velocity over a 1 m x 1.5 m hood opening?
3.75 m³/s
At that flow rate, what is the velocity of air in a 30 cm diameter round duct?
53.57 m/s
What is the WBGT for 33°C air, 30°C globe, 28°C wet bulb (indoors)?
Hint: Indicates heat stress level based on temperature and humidity.
28.6°C
Hypoxia results when the respiratory system is exposed to:
Hint: Condition caused by insufficient oxygen levels in the air.
A decreased oxygen atmosphere.
When should control strategies for an occupational health hazard be considered?
Hint: Consideration during initial design phases to mitigate risks.
During the design of the process system.
Chemical contaminants may gain access to the human biological system by:
Hint: Pathways for harmful substances to enter the body.
Inhalation, absorption and ingestion.
700 ppm methane (MW 16) equals how many mg/m³?
Hint: Concentration of gas measured in milligrams per cubic meter.
458 mg/m³
Breaking a liquid into a dispersed state is called:
Hint: A type of aerosol consisting of tiny liquid droplets.
Mist.
Air in a chemical laboratory contains 35 ppm of methanol (TLV 200 ppm), 60 ppm of isobutyl acetate (TLV 150 ppm), and 55 ppm of xylene (TLV 100 ppm). Has the TLV of this mixture been exceeded:
a. Yes, almost double the TLV
b. No, only about one-half the TLV
c. Yes, slightly over the TLV
d. No, only one-tenth the TLV
Hint: Mixture concentration exceeds individual TLVs.
Yes, slightly over the TLV.
Yes, slightly over the TLV.
This indicates a potential health risk, as prolonged exposure to concentrations above the TLV can lead to adverse health effects, including respiratory issues and neurological symptoms.
The TLV-TWA represents a concentration that:
a. Should never be exceeded
b. May be exceeded in certain circumstances
c. Must not be exceeded at any time
d. Is safe for all workers
Hint: Indicates a permissible exposure level under specific conditions.
May be exceeded in certain circumstances.
This concentration is often used in occupational health to ensure that workers are not exposed to harmful levels of substances over an 8-hour workday. Understanding these limits is crucial for maintaining workplace safety and compliance with health regulations.
Colourimetric detector tubes typically have an accuracy of ±:
a. 10%
b. 25%
c. 5%
d. 50%
Colourimetric tubes are often used in field sampling due to their portability and ease of use, allowing for quick assessments of air quality in various environments.
Hint: Typically used for measuring gas concentrations.
0.25
Colourimetric tubes are often used in field sampling due to their portability and ease of use, allowing for quick assessments of air quality in various environments.
The test method used to check respirator fit every time it is donned is:
a. Qualitative fit test
b. Quantitative fit test
c. Bitrex test
d. Positive pressure/negative pressure check
Hint: Method to ensure proper seal and protection during use.
Positive pressure/negative pressure check.
This method is essential for ensuring that the respirator forms a proper seal against the face, which is critical for effective protection against airborne contaminants. Regular checks help maintain safety standards and compliance with occupational health regulations.
In local exhaust ventilation, the most important characteristic is:
a. High duct velocity
b. Large fan size
c. Air changes per hour
d. Capture of the contaminant at the point of generation
This method is crucial for ensuring effective protection against airborne contaminants.
Hint: Focuses on removing harmful substances at their source.
Capture of the contaminant at the point of generation.
This method is crucial for ensuring that the equipment effectively protects the user from inhaling harmful substances. Regular fit checks help identify any issues with the seal that could compromise safety during use.
Two 85 dBA machines operating together produce approximately:
a. 90 dBA
b. 88 dBA
c. 85 dBA
d. 170 dBA
Hint: Two machines at 85 dBA each result in a combined sound level increase.
88 dBA.
Biological effects of microwave radiation include:
a. Skin cancer
b. DNA mutation
c. Body heating and eye cataracts
d. Bone marrow suppression
Body heating and eye cataracts.
The airflow needed to provide 5 air changes per hour in a 3 m × 7.5 m × 29 m room is:
a. 0.91 m³/s
b. 1.50 m³/s
c. 0.45 m³/s
d. 2.10 m³/s
Hint: Calculate airflow by multiplying room volume by air changes per hour.
0.91 m³/s.
The airflow calculation is essential for maintaining indoor air quality and ensuring that contaminants are effectively diluted and removed. Proper ventilation design can also contribute to energy efficiency and comfort within the space.
Lasers are potential eye hazards because:
a. They produce extremely high light radiation in a narrow wavelength
b. They emit ultraviolet radiation only
c. They always cause retinal burns
d. They produce ionizing radiation
Hint: High-intensity light that can damage vision.
They produce extremely high light radiation in a narrow wavelength.
Workers using vibrating hand tools may suffer from:
a. Carpal tunnel syndrome
b. Tendonitis
c. Raynaud’s Syndrome
d. Osteoporosis
Hint: Condition affecting blood flow in extremities.
Raynaud’s Syndrome.
The fluid in the anterior chamber of the eye is called:
a. Vitreous humor
b. Aqueous humor
c. Corneal fluid
d. Retinal fluid
This fluid is essential for maintaining the eye’s shape and providing nutrients.
Hint: Plays a key role in intraocular pressure.
Aqueous humor.
This fluid plays a crucial role in maintaining intraocular pressure and providing nutrients to the avascular structures of the eye, such as the lens and cornea.
Dilution ventilation is best suited when:
a. Contaminants are highly toxic
b. Contaminants are highly flammable
c. Contaminants are generated at very high rates
d. Air contaminants are not highly flammable or toxic and are not produced at high rates
Hint: Suitable for low-risk air contaminants.
Air contaminants are not highly flammable or toxic and are not produced at high rates.
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Applied Safety Fundamentals70
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Risk Management31
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Law and Ethics27
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occupational Hygiene27
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Auditing25
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Fire prevention and protection12
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Management systems8
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health and wellness8
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Ergonomics8
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PART 2 Applied Safety Fundamentals70
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Risk Management 230
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Law and Ethics 226
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Management System 28
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Applied safety 370
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Risk 330
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Law 326
