CIH General Practice 3 — Questions and Answers
Question 1: A CIH must determine if a new solvent meets the definition of a 'health hazard' under OSHA's Hazard Communication Standard. Which criterion applies?
- The chemical appears on any state right-to-know list
- It is classified as a health hazard based on evidence using GHS criteria (Correct answer)
- It has a vapor pressure above 0.1 mmHg at 25°C
- The chemical has an LD50 below 500 mg/kg in rats
Correct answer: It is classified as a health hazard based on evidence using GHS criteria
Under OSHA HazCom (29 CFR 1910.1200), health hazard classification follows GHS-aligned criteria based on scientific evidence of toxicological effects.
Question 2: What is the primary purpose of conducting a baseline audiogram for workers enrolled in a hearing conservation program?
- To meet OSHA's mandatory pre-placement physical requirement
- To establish a reference audiogram against which future tests are compared for Standard Threshold Shifts (Correct answer)
- To determine whether the worker is currently experiencing noise-induced hearing loss
- To document the employer's compliance with the ACGIH TLV for noise
Correct answer: To establish a reference audiogram against which future tests are compared for Standard Threshold Shifts
The baseline audiogram serves as the reference point for detecting a Standard Threshold Shift (STS) of 10 dB or more in subsequent annual audiograms.
Question 3: Which ventilation parameter most directly determines whether a local exhaust ventilation (LEV) hood will capture a contaminant?
- Static pressure at the fan inlet
- Face velocity or capture velocity at the hood opening (Correct answer)
- Duct transport velocity inside the ductwork
- Total system resistance measured in inches of water gauge
Correct answer: Face velocity or capture velocity at the hood opening
Capture velocity is the air velocity at the contaminant source needed to overcome ambient air currents and draw the contaminant into the hood.
Question 4: A worker develops contact dermatitis on the hands after starting a new job. The most appropriate first investigative step is to:
- Recommend immediate use of heavy-duty neoprene gloves
- Obtain a thorough occupational and exposure history (Correct answer)
- Perform patch testing for all chemicals in the workplace
- Refer the worker to a dermatologist for treatment
Correct answer: Obtain a thorough occupational and exposure history
A detailed occupational and exposure history is the essential first step to identify potential causative agents before implementing controls or referrals.
Question 5: Under the hierarchy of controls, substitution is preferred over engineering controls primarily because:
- Substitution is always less expensive to implement
- It eliminates or reduces the hazard at the source rather than containing it (Correct answer)
- Engineering controls require more worker training
- OSHA regulations mandate substitution before other controls
Correct answer: It eliminates or reduces the hazard at the source rather than containing it
Substitution removes or reduces the intrinsic hazard, while engineering controls merely contain or limit exposure without eliminating the hazardous agent.
Question 6: The skin notation (Sk) assigned to a chemical in the ACGIH TLV booklet indicates that:
- The chemical causes severe dermal corrosion
- Significant skin absorption may contribute to the overall systemic dose (Correct answer)
- Personal protective equipment must be worn at all times
- The dermal route is more toxic than the inhalation route
Correct answer: Significant skin absorption may contribute to the overall systemic dose
The ACGIH 'Sk' notation warns that skin absorption can contribute meaningfully to the total body burden and should be considered when assessing compliance with the TLV.
Question 7: When evaluating asbestos exposure using phase contrast microscopy (PCM), the result is expressed as:
- Mass of asbestos per cubic meter (mg/m³)
- Fibers per cubic centimeter (f/cc) (Correct answer)
- Particles per million (ppm)
- Number of fibers per gram of lung tissue
Correct answer: Fibers per cubic centimeter (f/cc)
PCM asbestos results are reported in fibers per cubic centimeter (f/cc), consistent with OSHA's PEL of 0.1 f/cc as an 8-hour TWA.
CIH General Practice 3
A CIH must determine if a new solvent meets the definition of a 'health hazard' under OSHA's Hazard Communication Standard.
Which criterion applies?