Free Mold Remediation Specialist (MRS) Examination Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Mold Remediation Specialist (MRS) Examination practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1A mold remediation employee undergoes an OSHA-accepted quantitative fit test for a tight-fitting half-facepiece respirator. What is the minimum fit factor needed to pass?

   1. A.10
   2. B.50
   3. C.100Correct answer: C
   4. D.500

   Explanation: OSHA states that a fit factor "equal to or greater than 100 for tight-fitting half facepieces" passes the quantitative fit test. The minimum is therefore 100; the 500 threshold applies to tight-fitting full facepieces.

   Reference: OSHA Respiratory Protection Standard — 29 CFR 1910.134(f)(7)

2. 2A remediator documents how a water-damaged plywood subfloor dries over several days. Which instrument is designed to monitor the moisture content of the material?

   1. A.Moisture meterCorrect answer: A
   2. B.Hygrometer
   3. C.Manometer
   4. D.Particle counter

   Explanation: EPA notes that "Moisture meters may be helpful for measuring the moisture content in a variety of building materials" and can monitor drying. The other instruments measure different environmental properties.

   Reference: Mold Remediation in Schools and Commercial Buildings: Chapter 3 — Equipment, Moisture Meters

3. 3A sealed mold-remediation containment is compared with the adjacent space using a pressure gauge. Which reading has the direction EPA recommends to limit contaminant migration?

   1. A.−2.5 pascalsCorrect answer: A
   2. B.+5.8 pascals
   3. C.+0.1 pascals
   4. D.0.0 pascals

   Explanation: EPA states that containment "must be maintained under negative pressure relative to surrounding areas" to limit airflow out to adjacent areas. The negative reading has that direction; the guide does not prescribe the specific magnitude shown.

   Reference: Mold Remediation in Schools and Commercial Buildings: Chapter 3 — Containment, Limited Containment

4. 4A wall adjacent to a mold-remediation area has clean-water damage, has been wet for less than 48 hours, and has no mold growth. The gypsum board has obvious swelling and open seams. What does EPA's water-damage guidance recommend for this wallboard?

   1. A.Remove, discard and replace itCorrect answer: A
   2. B.Dry it in place and retain it
   3. C.Remove, dry and reinstall it
   4. D.Dry it in place and reseal it

   Explanation: EPA states that wallboard "May be dried in place if there is no obvious swelling and the seams are intact. If not, remove, discard, and replace." The stated damage fails both conditions.

   Reference: EPA Mold Remediation Guide: Water Damage Cleanup and Mold Prevention — Table 1, Wallboard

5. 5A school remediation plan includes water-damaged items with no mold growth yet. Under EPA's key steps, what is the latest time within which these items should be dried to help prevent mold growth?

   1. A.12 hours
   2. B.24 hours
   3. C.48 hoursCorrect answer: C
   4. D.72 hours

   Explanation: EPA's key steps say to "Dry non-moldy items within 48 hours." This is the stated outer deadline; drying sooner is consistent with the guidance.

   Reference: Mold Remediation in Schools and Commercial Buildings: Chapter 3 — Mold Remediation - Key Steps

6. 6An employer selects a half-mask air-purifying respirator for a remediation employee under an effective OSHA respiratory protection program. Which assigned protection factor applies to this respirator?

   1. A.5
   2. B.10Correct answer: B
   3. C.25
   4. D.50

   Explanation: OSHA's Table 1 lists "1. Air-Purifying Respirator" with an assigned protection factor of 10 in the half-mask column. The other values correspond to other respirator configurations.

   Reference: OSHA Respiratory Protection Standard — 29 CFR 1910.134(d)(3)(i)(A), Table 1, Air-Purifying Respirator row

7. 7A firm plans a covered mold-remediation renovation in a residential dwelling unit of target housing under EPA's lead renovation rule. What is the maximum number of days before work begins that the firm may provide the required pamphlet to the owner?

   1. A.30 days
   2. B.60 daysCorrect answer: B
   3. C.90 days
   4. D.120 days

   Explanation: The rule says "No more than 60 days before beginning renovation activities" the firm must provide the pamphlet to the owner and follow the specified acknowledgment or mailing requirements. The question asks for the maximum advance window.

   Reference: EPA Information Distribution Requirements for Lead Renovation — 40 CFR 745.84(a)(1)

8. 8A remediation crew needs to establish negative pressure in an initially neutral containment, with a controlled makeup-air opening. Which HEPA-filtered fan arrangement does EPA give as an example that can establish the required pressure relationship?

   1. A.Exhaust containment air outdoorsCorrect answer: A
   2. B.Recirculate air within the containment
   3. C.Supply outdoor air into the containment
   4. D.Supply and exhaust air at equal rates

   Explanation: EPA says negative pressure can be created with "a HEPA-filtered fan unit exhausted outside of the building." The exhaust arrangement removes air from the containment; recirculation, supply alone and balanced supply and exhaust do not provide the same net exhaust.

   Reference: Mold Remediation in Schools and Commercial Buildings: Chapter 3 — Containment, Limited Containment

9. 9A remediation crew is double-bagging unsalvageable mold-contaminated building materials under EPA's mold course guidance. What minimum polyethylene bag thickness does the guide specify?

   1. A.2 mil
   2. B.4 mil
   3. C.6 milCorrect answer: C
   4. D.8 mil

   Explanation: EPA recommends double-bagging in "6-mil or thicker polyethylene bags." Six mil is the minimum stated thickness; thicker bags also satisfy that part of the guidance.

   Reference: EPA Mold Course: Remediation and Cleanup — Lesson 2, Throw Away Damaged Materials

10. 10After a successful school remediation, the manager plans humidity control to prevent future mold. When feasible, what indoor relative humidity range does EPA identify as ideal?

    1. A.10–30 percent
    2. B.20–40 percent
    3. C.30–50 percentCorrect answer: C
    4. D.50–70 percent

    Explanation: EPA recommends maintaining indoor humidity below 60% and says "ideally 30-50%, if possible." This is a preventive guideline, not an unconditional regulatory limit.

    Reference: Mold Remediation in Schools and Commercial Buildings: Prevention — Mold Prevention Tips