The Construction Health and Safety Technician credential—known as the CHST—is awarded by the Board of Certified Safety Professionals (BCSP). It is one of the most widely recognized certifications for safety professionals working on construction sites, in contractor organizations, and in construction management firms. The CHST demonstrates that the holder has the technical knowledge and practical skills to identify, evaluate, and control construction hazards across all phases of a project.
The CHST examination consists of 200 questions administered over four hours. Candidates must score at least 70 percent to pass. The exam is computer-based and offered at Prometric testing centers. Once certified, CHST holders must recertify every five years by accumulating safety development points through continuing education, professional activities, or re-examination. Understanding the exam's content domains thoroughly is the most reliable path to passing on the first attempt, and working through a printed practice test PDF is one of the best ways to prepare.
The CHST exam places significant weight on safety management systems, hazard identification processes, and the structure of effective safety programs. Candidates must understand how safety programs are built, how hazards are found and documented, and how incidents are investigated once they occur.
A Job Hazard Analysis (JHA)—sometimes called a Job Safety Analysis—is the foundational tool for hazard identification in construction. A JHA breaks a task down into sequential steps, identifies the hazards present at each step, and specifies the controls that eliminate or reduce each hazard. Writing thorough JHAs is a core competency tested on the CHST exam. Candidates should understand who participates in a JHA, when JHAs must be revised, and how they differ from broader safety program documents.
The OSHA inspection process is another management topic that appears frequently. OSHA conducts programmed inspections based on high-hazard industry targeting and unprogrammed inspections in response to complaints, referrals, and fatalities. On construction sites, OSHA inspectors have the right to inspect without advance notice. Employers may require the inspector to obtain a warrant if access is refused, but most inspections proceed without one. Understanding citation types—willful, serious, other-than-serious, repeat, and failure to abate—and the associated penalty ranges is important for the exam.
Incident investigation requires identifying both immediate causes and root causes. Heinrich's triangle—also called the accident triangle or safety triangle—describes the statistical relationship between near misses, minor injuries, and major injuries. The original ratio proposed by Herbert Heinrich was 300 near misses for every 29 minor injuries for every 1 major injury. Modern research has modified the specific ratios, but the underlying principle—that reducing near misses reduces the frequency of serious events—remains central to construction safety management. Near-miss reporting programs depend on a no-blame culture and management commitment to corrective action.
OSHA identifies four hazard categories that account for the majority of construction fatalities each year: falls, struck-by incidents, caught-in/between incidents, and electrocution. The CHST exam tests detailed knowledge of each category.
Fall protection is required whenever workers are exposed to a fall of six feet or more in construction (four feet in general industry). The three accepted methods of fall protection are guardrail systems, personal fall arrest systems (PFAS), and safety nets. Guardrail systems must withstand a force of at least 200 pounds applied downward or outward and must include a top rail at 42 inches (plus or minus 3 inches), a mid-rail, and toe boards when required. A personal fall arrest system includes a full-body harness, a connecting lanyard or self-retracting lifeline, and an anchorage capable of supporting at least 5,000 pounds per worker attached—or designed by a qualified person to maintain a safety factor of at least two. Leading edge work—installing decking or roofing at the edge of an advancing work surface—presents particular fall hazards that require pre-planning and approved fall protection systems before work begins.
Struck-by hazards arise when workers are hit by moving objects including swinging crane loads, vehicles in roadways, flying debris from power tools, and falling objects from above. Controls include exclusion zones around cranes during picks, hard barricades separating pedestrians from vehicle traffic, tool lanyards on elevated work platforms, and the mandatory wearing of high-visibility apparel in roadway construction zones.
Caught-in/between hazards include excavation cave-ins, which are among the most deadly construction incidents. An unprotected trench can collapse with enough force to crush a worker before rescue is possible. OSHA requires protective systems in all excavations deeper than five feet unless the excavation is entirely in stable rock. Protective systems include sloping (cutting trench walls back to a safe angle), shoring (supporting trench walls with hydraulic shores or timber), and shielding (placing a trench box that protects workers within it). Caught-in/between hazards also include unguarded rotating machinery, pinch points on equipment, and excavation edges that collapse under vehicle loads.
Electrocution hazards on construction sites include contact with overhead power lines, use of damaged electrical tools and cords, and work near buried utilities. OSHA requires ground fault circuit interrupter (GFCI) protection on all 120-volt, single-phase, 15- and 20-ampere receptacle outlets used for construction. An assured equipment grounding conductor program is an alternative to GFCI protection on certain circuits. Lockout/tagout procedures must be followed during installation, maintenance, and repair of electrical equipment to prevent unexpected energization.
Excavation and trenching is one of the most tested topics on the CHST exam because of the severity and frequency of fatalities in this hazard category. Candidates must understand OSHA's soil classification system and the protective system requirements that apply to each soil type.
OSHA classifies soil into three types: Type A, Type B, and Type C. Type A soil is the most stable and includes hard clay, cemented soils, and other cohesive soils with unconfined compressive strength greater than 1.5 tons per square foot. Type A soil cannot be classified as such if it is fissured, subject to vibration, has been previously disturbed, or is part of a sloped or layered system where failure could occur. Type B soil includes previously disturbed soils, soils subject to ground-water seepage, and soils with an unconfined compressive strength between 0.5 and 1.5 tons per square foot. Type C soil is the least stable—granular soils such as sand and gravel, soils subject to water infiltration, and soils with unconfined compressive strength of 0.5 tons per square foot or less.
A competent person must classify soils before work begins, inspect excavations daily, and inspect after any condition change including rain, frost, or vibration from nearby equipment. The competent person has both the knowledge to identify hazards and the authority to take corrective action immediately. Water accumulation in an excavation is an immediate hazard requiring work stoppage until the water is controlled. Access and egress must be provided within 25 feet of all workers in excavations four feet deep or deeper.
Scaffolding is required on most construction projects and is the subject of OSHA's most frequently cited construction standard. The CHST exam tests both supported scaffold requirements and suspended scaffold requirements.
Supported scaffolds—including frame scaffolds, systems scaffolds, and pump jack scaffolds—must be capable of supporting at least four times the maximum intended load (a 4:1 safety factor). Platforms must be fully planked and must not have gaps greater than one inch unless the gap is necessary for the work. The scaffold must be erected on base plates and mud sills adequate for the load. Access and egress must be provided by portable ladders, stair towers, or built-in scaffold access frames—never by cross-braces used as climbing devices. Fall protection in the form of guardrails or a personal fall arrest system is required on scaffolds ten feet or more above a lower level.
Suspended scaffolds are supported from overhead structures by ropes or other non-rigid means. Two-point (swing stage) scaffolds are the most common type and require a 6:1 safety factor on suspension ropes. All scaffolding must be erected, moved, dismantled, or altered only under the supervision of a competent person qualified in scaffold construction. A scaffold competent person must inspect all scaffolding before each work shift and after any event that could have affected its structural integrity.
Every construction employer with more than ten employees must have a written emergency action plan. Smaller employers may communicate the plan orally. The plan must address procedures for reporting emergencies, evacuating the site, accounting for all workers after evacuation, performing rescue and medical duties, and contacting emergency services.
Construction sites present unique emergency challenges because the worksite configuration changes continuously, workers from multiple employers may be on-site simultaneously, and temporary structures may obstruct egress. The general contractor is typically responsible for coordinating emergency response among all subcontractors on the site and for ensuring that all workers—including those employed by subcontractors—are trained on the emergency procedures applicable to their work area.
First aid and CPR training requirements under OSHA require that in the absence of an infirmary, clinic, or hospital near the worksite, a person trained in first aid must be available at the worksite. On large construction projects this typically means having multiple first aid-trained workers on each shift. Emergency equipment including first aid kits, eye wash stations, and fire extinguishers must be accessible and maintained in working condition.
Fire prevention on construction sites requires controlling ignition sources, storing flammable and combustible materials properly, maintaining adequate clearances around heating equipment, and ensuring that fire extinguishers of the correct type and size are available and regularly inspected. Temporary heating equipment must be approved for the fuel type in use and must be used with adequate ventilation to prevent carbon monoxide buildup in enclosed spaces.
The CHST exam tests a broad range of knowledge, and candidates come from diverse backgrounds—some with extensive field experience but limited regulatory knowledge, others with strong regulatory backgrounds but less hands-on construction exposure. An effective study plan accounts for individual gaps rather than treating all topics equally.
Start by downloading the official BCSP CHST exam blueprint, which lists the content domains and the approximate percentage of exam questions devoted to each. Use the blueprint to create a proportional study schedule. If fall protection and excavation together account for 30 percent of exam questions, spend roughly 30 percent of your study time on those topics. Many candidates over-invest in topics they find interesting and under-invest in areas where they are weak—the blueprint keeps you honest.
OSHA's construction standards (29 CFR Part 1926) are the primary regulatory reference for the CHST exam. The most heavily tested subparts include Subpart C (general safety and health provisions), Subpart E (personal protective equipment), Subpart K (electrical), Subpart L (scaffolding), Subpart M (fall protection), Subpart P (excavations), and Subpart Q (concrete and masonry). Reading the actual regulatory text—not just summaries—is important because exam questions often test specific thresholds, numerical limits, and procedural requirements that summaries frequently simplify or omit.
Practice tests are most valuable when used diagnostically. After completing a practice exam, sort your missed questions by topic and look up the relevant OSHA standard for each. Build a personal reference sheet of the specific numbers and exceptions you keep missing—training hour minimums, load capacity requirements, distance thresholds, concentration limits. Review this reference sheet in the days before the exam.
On exam day, read each question carefully and eliminate obviously incorrect answers before selecting your best choice. Many CHST questions include distractors that are partially correct—the distinction between the correct answer and a close distractor often hinges on a single word like "must" vs. "may" or a specific numerical threshold. Managing time is also important: with 200 questions in 240 minutes you have slightly more than one minute per question, which is enough time if you avoid dwelling on questions where you are uncertain. Flag uncertain questions and return to them after completing the rest of the exam.