10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The CDS exam has 110 questions and runs 2 hours 30 minutes.
These 10 free CDS questions are organized by exam domain, so you can see how each part of the Certified Demolition Supervisor (CDS) blueprint is tested. Reveal the answer and explanation under each question.
A crew will chip concrete indoors with handheld powered chipping tools for 90 minutes. Continuous water at the impact point and the required indoor exhaust are properly provided. No other silica-generating tasks are assigned that shift. The employer is using OSHA's silica Table 1 approach. What respiratory protection does that table specify for this task?
Correct answer: A - A respirator with an assigned protection factor of at least 10.
A qualified person has designed a complete personal fall-arrest system for one worker with a documented safety factor of 2.4. Its 4,200-lb anchorage is independent of platform supports. Installation and use remain under that person's supervision; clearance, component compatibility, and all other system requirements have been verified. A foreperson rejects the anchorage solely because it is below 5,000 lb. Under OSHA's construction rule, that objection is:
Correct answer: C - Invalid; this system meets the qualified-design alternative to 5,000 lb.
During a permitted entry into a vault scheduled for removal, a worker becomes unresponsive and the oxygen monitor alarms at 17.8%. The trained attendant has summoned the designated rescue service. The entrant is connected to a properly installed retrieval system; the employer's rescue plan calls for non-entry retrieval, and the retrieval path is clear. What is the appropriate action while responders are traveling to the site?
Correct answer: D - Begin the planned retrieval from outside the vault.
A planned complete demolition of a commercial warehouse is covered by the federal asbestos NESHAP. A thorough asbestos inspection found no asbestos-containing material. The city has issued a demolition permit, but no notice has been sent to the NESHAP administering authority. This is not an emergency demolition. Which federal asbestos notification requirement still applies?
Correct answer: D - Give the administering authority at least 10 working days' advance notice of demolition.
Demolition fines destined for disposal are subject to federal RCRA hazardous-waste determination, with no applicable exclusion. A representative TCLP extract contains 6.8 mg/L lead. A worker's personal air sample during handling is 18 µg/m³ as an eight-hour average. The foreperson proposes an ordinary construction-waste landfill because the air result is low. Which finding controls the lead toxicity-characteristic decision?
Correct answer: C - The TCLP result exceeds 5.0 mg/L, so the waste exhibits the D008 lead characteristic.
Selective demolition will remove a floor while retaining the exterior masonry facade. The engineering survey identifies the floor-to-wall ties as the wall's lateral restraint. An accepted temporary-bracing design is available, but the bracing has not been installed. Which revision belongs in the removal sequence?
Correct answer: C - Install and verify the temporary bracing before releasing the floor-to-wall ties.
A truck has a 20-cubic-yard body and a maximum permitted payload of 12 US short tons, after all vehicle and axle restrictions are accounted for. The uniform rubble's measured loose density is 0.80 short ton per cubic yard. To use the truck's capacity without exceeding either limit, the loading supervisor should cap each load at:
Correct answer: B - 15 loose cubic yards.
A designer's response to a request for information confirms that an unshown concrete equipment pad is outside the demolition contract's original scope. The client's maintenance foreperson asks the crew to remove it. The contract requires written authorization from the owner's named contract representative for extra work. The pad is stable and isolated; other released work is independent of it. How should today's work be organized?
Correct answer: D - Keep crews on released, unaffected work while obtaining written pad-removal authorization from the named representative.
At a rehearsal for a revised excavator crossing, a worker correctly describes the crush hazard but opens the pedestrian gate before the operator's agreed all-clear. The worker attended the briefing and passed its written quiz. What would justify assigning the worker to control the crossing independently?
Correct answer: B - Correct execution of the gate-release sequence in an observed recheck after coaching.
Near-miss reports rise sharply after a supervisor simplifies reporting and begins telling crews how their concerns were resolved. Work hours, task mix, and reporting criteria are unchanged. Independent inspections show no corresponding increase in uncontrolled hazards. At the project review, which interpretation is warranted?
Correct answer: A - Improved reporting is a plausible explanation; compare event patterns with independent evidence of exposure.
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