OHST flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Total Recordable Incident Rate
- Multiply the number of OSHA recordable cases by 200,000 and divide by total employee hours worked. The 200,000 constant equals 100 full-time workers at 40 hours for 50 weeks.
- DART Rate Calculation
- Days Away, Restricted, or Transferred rate: multiply DART cases by 200,000 and divide by hours worked. It counts only recordable cases with days away, restricted work, or job transfer.
- Fatality Reporting Deadline
- Under 29 CFR 1904.39 an employer must report a work-related fatality to OSHA within 8 hours of learning of it, by telephone or the online reporting form.
- General Duty Clause
- OSH Act Section 5(a)(1) requires employers to furnish a workplace free from recognized hazards likely to cause death or serious physical harm, where a feasible means of abatement exists.
- Hierarchy of Controls
- Ranked from most to least effective: elimination, substitution, engineering controls, administrative controls, and personal protective equipment. PPE ranks last because effectiveness depends on individual behavior and fit.
- Leading Indicator
- A preventive measure that predicts future safety performance, such as inspections completed, near-miss reports, or training hours. It contrasts with lagging indicators like injury and illness rates.
- Plan-Do-Check-Act Cycle
- The continual improvement model used in ANSI/ASSP Z10 and ISO 45001 safety management systems: establish objectives, implement controls, evaluate results, and correct deficiencies before repeating the cycle.
- TLV Short-Term Exposure Limit
- A 15-minute time-weighted average concentration that should not be exceeded at any time during the workday, permitted no more than four times daily with at least 60 minutes between excursions.
- Ceiling Exposure Limit
- A concentration that must never be exceeded at any point during the work shift, even instantaneously. Ceiling values govern fast-acting substances for which an 8-hour average is inadequate protection.
- ppm to mg/m3 Conversion
- At 25 degrees Celsius and one atmosphere, mg/m3 equals ppm multiplied by molecular weight and divided by 24.45. At 0 degrees Celsius the molar volume constant is 22.4 instead.
- Noise Dose Formula
- D equals 100 times the sum of exposure time at each noise level divided by the time allowed at that level. A dose above 100 percent exceeds the permissible exposure limit.
- OSHA Noise Exchange Rate
- OSHA uses a 5-decibel exchange rate, so each 5 dBA increase halves the permissible exposure time: 90 dBA for 8 hours, 95 dBA for 4 hours. NIOSH uses 3 dB.
- Hearing Conservation Action Level
- A hearing conservation program is required when noise exposure equals or exceeds the 85 dBA action level as an 8-hour TWA, including monitoring, audiometric testing, hearing protection, and training.
- Oxygen Deficient Atmosphere
- An atmosphere containing less than 19.5 percent oxygen by volume. Confined space entry requires pre-entry and continuous monitoring; concentrations above 23.5 percent are oxygen enriched.
- Permit-Required Confined Space
- A space with limited entry and exit, not designed for continuous occupancy, that contains a hazardous atmosphere, engulfment potential, entrapment configuration, or other recognized serious hazard. Entry requires a permit.
- Excavation Protective System Threshold
- Excavations 5 feet or deeper need a protective system unless a competent person finds no collapse indication. At 4 feet, a means of egress within 25 feet of lateral travel is required.
- Fall Protection Trigger Heights
- Fall protection is required at 6 feet in construction, 4 feet in general industry, and 10 feet on scaffolds. Guardrails, safety nets, or personal fall arrest systems are acceptable controls.
- Lockout Tagout Verification
- 29 CFR 1910.147 requires the authorized employee to verify de-energization after applying locks and tags, normally by attempting startup or testing for zero energy state.
- Job Hazard Analysis Steps
- Select the job, break it into sequential steps, identify hazards at each step, and determine controls. Results are documented and communicated to the workers who perform the task.
- HAZOP Guide Words
- A process hazard method that applies words such as no, more, less, reverse, part of, and as well as to process parameters to systematically find deviations from design intent.
- Risk Score Calculation
- Risk equals likelihood multiplied by severity. The score is plotted on a risk matrix to rank hazards and set the priority and urgency of control measures.
- Fire Tetrahedron
- Four elements are needed for combustion: fuel, oxygen, heat, and a self-sustaining chemical chain reaction. Removing any one element extinguishes the fire.
- Class C Fire
- A fire involving energized electrical equipment. Carbon dioxide and dry chemical extinguishers are used; water must not be applied until the circuit is de-energized.
- PASS Technique
- Pull the pin, Aim at the base of the fire, Squeeze the handle, Sweep side to side. Portable extinguishers are used only on incipient-stage fires by trained employees.
- Class A Extinguisher Distance
- OSHA requires Class A extinguishers placed so no employee travels more than 75 feet to reach one. Class B spacing is 30 to 50 feet depending on hazard.
- Written EAP Threshold
- 29 CFR 1910.38 requires a written emergency action plan when 11 or more employees are present at the site. Smaller employers may communicate the plan orally.
- Exit Route Dimensions
- Exit routes must be at least 28 inches wide at all points and kept unobstructed. Emergency lighting must function during power loss, with NFPA 101 setting a 90-minute minimum.
- RCRA Ignitability Characteristic
- A hazardous waste characteristic defined by a flash point below 140 degrees Fahrenheit, or by being spontaneously combustible, an ignitable compressed gas, or an oxidizer.
- RCRA Corrosivity Characteristic
- A hazardous waste characteristic defined by an aqueous pH of 2 or less, or 12.5 or greater, or by the ability to corrode steel faster than 6.35 millimeters per year.
- Large Quantity Generator
- A RCRA generator producing 1,000 kilograms or more of hazardous waste per month, or more than 1 kilogram of acutely hazardous waste, limited to 90 days on-site accumulation.
- CERCLA Reportable Quantity
- Under CERCLA, a release of a hazardous substance equal to or greater than its assigned reportable quantity must be reported immediately to the National Response Center.
- Tier II Report Deadline
- Under EPCRA Section 312, facilities storing hazardous chemicals at or above threshold quantities must submit a Tier II inventory report to state and local agencies by March 1 annually.