STS cheat sheet

Risk score formula: R = P × S, where P is likelihood and S is severity; higher products indicate higher-priority hazards.

Hierarchy of controls order: elimination, substitution, engineering controls, administrative controls, personal protective equipment.

Job hazard analysis steps: select the job, break it into steps, identify hazards, assess risk, specify controls, communicate, and review.

Exposure ratio = measured worker exposure ÷ applicable occupational exposure limit; a ratio greater than 1 indicates overexposure.

Lockout/tagout requires isolating all energy sources, applying locks and tags, and verifying a zero-energy state before maintenance or repair.

Confined-space entry atmosphere: oxygen commonly acceptable at 19.5% to 23.5%; test before entry and continuously or periodically during entry.

Machine guarding must prevent access to danger zones such as nip points, rotating parts, and points of operation.

Hazard categories include mechanical, electrical, chemical, thermal, pressure, radiation, biological, and ergonomic energy sources.

PDCA cycle: Plan-Do-Check-Act is the continual improvement sequence used in safety management systems.

Leading indicators are proactive measures such as inspections, near-miss reports, and training completion; lagging indicators are reactive measures such as injuries and lost-time cases.

ANSI/ASSP Z10 and ISO 45001 are management system frameworks built on policy, planning, implementation, evaluation, and improvement.

Supervisory safety duties include enforcing rules, correcting hazards, coaching workers, conducting inspections, and reviewing incident reports.

Stop-work authority allows workers or supervisors to halt tasks when they perceive imminent danger or unacceptable risk.

Safety culture indicators include leadership commitment, worker involvement, open reporting, just culture, and timely hazard correction.

Management review evaluates the safety management system’s suitability, adequacy, and effectiveness and sets improvement actions.

Accountability is answerability for outcomes, while responsibility is the assigned duty to perform a task or role.

OSHA General Duty Clause, Section 5(a)(1), requires employers to provide a workplace free from recognized hazards likely to cause death or serious physical harm.

29 CFR 1910 covers general industry, while 29 CFR 1926 covers construction.

Recordable injuries and illnesses must be entered on the OSHA 300 Log within 7 calendar days after the employer learns of the event.

Work-related fatalities must be reported to OSHA within 8 hours; in-patient hospitalization, amputation, or loss of an eye within 24 hours.

The OSHA 300A annual summary must be posted from February 1 through April 30.

Consensus standards such as ANSI, NFPA, and ASSP guidance are not directly enforceable unless adopted by a regulatory agency or incorporated into a contract.

Hazard Communication requirements include container labels, safety data sheets, and worker training.

OSHA Section 11(c) prohibits retaliation against workers for exercising safety and health rights.

Incident investigation should begin promptly while preserving the scene, equipment, materials, and evidence.

Root cause analysis methods include the Five Whys, fishbone diagram, and fault tree analysis.

Incidents usually have multiple contributing causes, including immediate acts or conditions and underlying system factors.

Witnesses should be interviewed separately to reduce cross-influence and compare accounts.

Corrective actions are ranked by durability; elimination and engineering controls are preferred over administrative measures or discipline alone.

A near miss is an unplanned event that did not cause injury, illness, or damage but had the potential to do so.

OSHA reporting deadlines are 8 hours for fatalities and 24 hours for in-patient hospitalization, amputation, or loss of an eye.

The OSHA 300 Log records specified injuries and illnesses; the 300A summary is posted annually.

Training needs assessment compares task requirements, worker knowledge, and performance gaps to determine who needs what training.

Measurable learning objectives state observable behavior, conditions, and a standard for acceptable performance.

Adult learning is strengthened by relevant, problem-centered content, use of prior experience, practice, and timely feedback.

Toolbox talks are short, task-specific safety discussions covering hazards, controls, and worker questions.

Training comprehension is verified through demonstration, questioning, or performance testing rather than attendance alone.

Communication barriers include noise, language differences, limited literacy, and unclear terminology.

Safety committees engage workers in hazard review, incident analysis, and program evaluation.

Incentive programs tied only to low injury rates can discourage injury and near-miss reporting.

Emergency action plan elements include reporting, evacuation or shelter, accounting for people, rescue duties, shutdown procedures, and communication.

Fire extinguisher use follows PASS: Pull the pin, Aim at the base, Squeeze the handle, Sweep the nozzle.

Evacuation moves occupants out of the hazard area; shelter-in-place keeps occupants inside and closes ventilation to protect from an outdoor hazard.

Drills should be evaluated for notification, evacuation time, accounting accuracy, and corrective actions.

A designated assembly area allows responsible persons to conduct a headcount and account for all personnel.

First aid, CPR, and AED readiness depend on trained responders, accessible equipment, and periodic checks.

Spill response sequence: isolate the area, notify responders, contain the material if trained and safe, and clean up according to the substance hazards.

Emergency communications must reach occupants and responders through alarms, notifications, and backup methods.