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OSHA 521 – OSHA GUIDE TO INDUSTRIAL HYGIENE
EXAMINATION 2026 COMPLETE (105) CURRENT TESTING
QUESTIONS AND CORRECT ANSWERS WITH DETAILED
RATIONALES.
OSHA
Prepare for the OSHA 521 – OSHA Guide to Industrial Hygiene Examination with this
comprehensive practice resource designed to support your exam preparation. It
features exam-style questions covering industrial hygiene principles, workplace
hazard recognition, exposure assessment, occupational health, control measures,
and OSHA standards. Use it to reinforce essential concepts, assess your knowledge,
and build confidence before test day. An excellent study aid for professionals
preparing for the OSHA 521 examination.
MULTIPLE CHOICE.
Question 1: In the context of the industrial hygiene conceptual model, which
action is typically the most effective and preferred method for controlling a
workplace hazard?
A. Implementing personal protective equipment (PPE)
B. Substituting a hazardous chemical with a less hazardous one
C. Implementing administrative controls like job rotation
D. Providing employee safety training
Correct answer: B. Substituting a hazardous chemical with a less
hazardous one
Rationale: The Hierarchy of Controls prioritizes elimination and
substitution as the most effective methods because they remove the
hazard at the source, rather than relying on worker behavior or barriers .
Question 2: According to the OSHA Respiratory Protection Standard (29 CFR
1910.134), what is the first step an employer must take to establish a
respiratory protection program?
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A. Fit-test all employees
B. Have a written respiratory protection program
C. Purchase respirators
D. Conduct medical evaluations
Correct answer: B. Have a written respiratory protection program
Rationale: The standard requires a written respiratory protection program
that includes worksite-specific procedures before any other
implementation steps are taken .
Question 3: A worker is exposed to noise levels that average 92 dBA over an 8-
hour work shift. According to the OSHA noise standard (29 CFR 1910.95),
what action is NOT required?
A. Implementation of a hearing conservation program
B. Provision of hearing protection at no cost
C. Annual audiometric testing
D. Engineering controls to reduce noise to 85 dBA
Correct answer: D. Engineering controls to reduce noise to 85 dBA
Rationale: OSHA requires feasible engineering or administrative controls
when exposures exceed the PEL of 90 dBA. The action level for a hearing
conservation program is 85 dBA, but engineering controls are not
mandated at that level .
Question 4: A worker's audiogram shows a standard threshold shift (STS).
According to the OSHA noise standard, what is the employer required to do?
A. Immediately remove the worker from noisy environments
B. Provide the worker with hearing protection, retest within 30 days, and refer
for a clinical evaluation if the shift persists
C. Post a warning sign on the employee's workstation
D. No action is required for a standard threshold shift
Correct answer: B. Provide the worker with hearing protection, retest
within 30 days, and refer for a clinical evaluation if the shift persists
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Rationale: When an STS is identified, the employer must fit the worker
with hearing protection, retest within 30 days, and refer the employee for
a clinical audiological evaluation if the shift is confirmed .
Question 5: A worker is exposed to noise levels that average 92 dBA over an 8-
hour work shift. According to the OSHA noise standard (29 CFR 1910.95),
what action is NOT required?
A. Implementation of a hearing conservation program
B. Provision of hearing protection at no cost
C. Annual audiometric testing
D. Engineering controls to reduce noise to 85 dBA
Correct answer: D. Engineering controls to reduce noise to 85 dBA
Rationale: OSHA requires feasible engineering or administrative controls
when exposures exceed the PEL of 90 dBA. The action level for a hearing
conservation program is 85 dBA, but engineering controls are not
mandated at that level .
Question 6: According to the OSHA Respiratory Protection Standard (29 CFR
1910.134), which of the following is NOT required as part of a written
respiratory protection program?
A. Worksite-specific procedures
B. Medical evaluations of employees
C. Fit-testing procedures
D. A requirement to purchase only NIOSH-approved respirators of a specific
color
Correct answer: D. A requirement to purchase only NIOSH-approved
respirators of a specific color
Rationale: A written program requires worksite-specific procedures,
medical evaluations, and fit-testing, but does not specify respirator
colors .
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Question 7: A worker's audiogram shows a standard threshold shift (STS).
According to the OSHA noise standard, what is the employer required to do?
A. Immediately remove the worker from noisy environments
B. Provide the worker with hearing protection, retest within 30 days, and refer
for a clinical evaluation if the shift persists
C. Post a warning sign on the employee's workstation
D. No action is required for a standard threshold shift
Correct answer: B. Provide the worker with hearing protection, retest
within 30 days, and refer for a clinical evaluation if the shift persists
Rationale: When an STS is identified, the employer must fit the worker
with hearing protection, retest within 30 days, and refer the employee for
a clinical audiological evaluation if the shift is confirmed .
Question 8: What is the primary role of an industrial hygienist?
A. Enforce OSHA standards
B. Treat occupational injuries
C. Anticipate, recognize, evaluate, and control workplace health hazards
D. Design safety equipment
Correct answer: C. Anticipate, recognize, evaluate, and control workplace
health hazards
Rationale: Industrial hygiene focuses on preventing occupational illness
through systematic identification, evaluation, and control of hazards .
Question 9: Which of the following is NOT one of the four basic industrial
hygiene principles?
A. Anticipation
B. Recognition
C. Enforcement
D. Control
OSHA 521 – OSHA GUIDE TO INDUSTRIAL HYGIENE
EXAMINATION 2026 COMPLETE (105) CURRENT TESTING
QUESTIONS AND CORRECT ANSWERS WITH DETAILED
RATIONALES.
OSHA
Prepare for the OSHA 521 – OSHA Guide to Industrial Hygiene Examination with this
comprehensive practice resource designed to support your exam preparation. It
features exam-style questions covering industrial hygiene principles, workplace
hazard recognition, exposure assessment, occupational health, control measures,
and OSHA standards. Use it to reinforce essential concepts, assess your knowledge,
and build confidence before test day. An excellent study aid for professionals
preparing for the OSHA 521 examination.
MULTIPLE CHOICE.
Question 1: In the context of the industrial hygiene conceptual model, which
action is typically the most effective and preferred method for controlling a
workplace hazard?
A. Implementing personal protective equipment (PPE)
B. Substituting a hazardous chemical with a less hazardous one
C. Implementing administrative controls like job rotation
D. Providing employee safety training
Correct answer: B. Substituting a hazardous chemical with a less
hazardous one
Rationale: The Hierarchy of Controls prioritizes elimination and
substitution as the most effective methods because they remove the
hazard at the source, rather than relying on worker behavior or barriers .
Question 2: According to the OSHA Respiratory Protection Standard (29 CFR
1910.134), what is the first step an employer must take to establish a
respiratory protection program?
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A. Fit-test all employees
B. Have a written respiratory protection program
C. Purchase respirators
D. Conduct medical evaluations
Correct answer: B. Have a written respiratory protection program
Rationale: The standard requires a written respiratory protection program
that includes worksite-specific procedures before any other
implementation steps are taken .
Question 3: A worker is exposed to noise levels that average 92 dBA over an 8-
hour work shift. According to the OSHA noise standard (29 CFR 1910.95),
what action is NOT required?
A. Implementation of a hearing conservation program
B. Provision of hearing protection at no cost
C. Annual audiometric testing
D. Engineering controls to reduce noise to 85 dBA
Correct answer: D. Engineering controls to reduce noise to 85 dBA
Rationale: OSHA requires feasible engineering or administrative controls
when exposures exceed the PEL of 90 dBA. The action level for a hearing
conservation program is 85 dBA, but engineering controls are not
mandated at that level .
Question 4: A worker's audiogram shows a standard threshold shift (STS).
According to the OSHA noise standard, what is the employer required to do?
A. Immediately remove the worker from noisy environments
B. Provide the worker with hearing protection, retest within 30 days, and refer
for a clinical evaluation if the shift persists
C. Post a warning sign on the employee's workstation
D. No action is required for a standard threshold shift
Correct answer: B. Provide the worker with hearing protection, retest
within 30 days, and refer for a clinical evaluation if the shift persists
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Rationale: When an STS is identified, the employer must fit the worker
with hearing protection, retest within 30 days, and refer the employee for
a clinical audiological evaluation if the shift is confirmed .
Question 5: A worker is exposed to noise levels that average 92 dBA over an 8-
hour work shift. According to the OSHA noise standard (29 CFR 1910.95),
what action is NOT required?
A. Implementation of a hearing conservation program
B. Provision of hearing protection at no cost
C. Annual audiometric testing
D. Engineering controls to reduce noise to 85 dBA
Correct answer: D. Engineering controls to reduce noise to 85 dBA
Rationale: OSHA requires feasible engineering or administrative controls
when exposures exceed the PEL of 90 dBA. The action level for a hearing
conservation program is 85 dBA, but engineering controls are not
mandated at that level .
Question 6: According to the OSHA Respiratory Protection Standard (29 CFR
1910.134), which of the following is NOT required as part of a written
respiratory protection program?
A. Worksite-specific procedures
B. Medical evaluations of employees
C. Fit-testing procedures
D. A requirement to purchase only NIOSH-approved respirators of a specific
color
Correct answer: D. A requirement to purchase only NIOSH-approved
respirators of a specific color
Rationale: A written program requires worksite-specific procedures,
medical evaluations, and fit-testing, but does not specify respirator
colors .
, Page 4 of 36
Question 7: A worker's audiogram shows a standard threshold shift (STS).
According to the OSHA noise standard, what is the employer required to do?
A. Immediately remove the worker from noisy environments
B. Provide the worker with hearing protection, retest within 30 days, and refer
for a clinical evaluation if the shift persists
C. Post a warning sign on the employee's workstation
D. No action is required for a standard threshold shift
Correct answer: B. Provide the worker with hearing protection, retest
within 30 days, and refer for a clinical evaluation if the shift persists
Rationale: When an STS is identified, the employer must fit the worker
with hearing protection, retest within 30 days, and refer the employee for
a clinical audiological evaluation if the shift is confirmed .
Question 8: What is the primary role of an industrial hygienist?
A. Enforce OSHA standards
B. Treat occupational injuries
C. Anticipate, recognize, evaluate, and control workplace health hazards
D. Design safety equipment
Correct answer: C. Anticipate, recognize, evaluate, and control workplace
health hazards
Rationale: Industrial hygiene focuses on preventing occupational illness
through systematic identification, evaluation, and control of hazards .
Question 9: Which of the following is NOT one of the four basic industrial
hygiene principles?
A. Anticipation
B. Recognition
C. Enforcement
D. Control
