OHS Glossary: 65 Key Terms Every Safety Professional Must Know
How to Use This Glossary
This reference covers 65 terms that appear regularly in OHS practice, risk assessment, incident management, and management system documentation. Terms are organized alphabetically for easy lookup.
For related deep-dive guides, follow the links within each definition.
A
ALARP (As Low As Reasonably Practicable) The legal standard for risk control in UK OHS law and many other jurisdictions — risk must be reduced to a level where the cost of further reduction is grossly disproportionate to the safety benefit achieved. Not "as cheap as possible" — "as low as reasonably achievable while maintaining proportionality." See: ALARP Principle Guide.
ALARA (As Low As Reasonably Achievable) The risk reduction standard used primarily in radiation protection (nuclear industry, medical radiation). Emphasizes continuous reduction toward the lowest achievable level, with less emphasis on the gross disproportion test used in ALARP. Not equivalent to ALARP despite similar wording.
Audit A systematic, independent examination of a management system, process, or output to determine whether it conforms to specified requirements. Internal audits are conducted by the organization's own personnel; external audits by third-party certification bodies. ISO 45001 Clause 9.2 requires regular internal OHS audits. See: OHS Internal Audit Guide.
B
Bowtie Diagram A risk visualization tool showing the relationship between causes, hazard, controls, and consequences. The left side of the bowtie shows causes leading to the "top event" (hazard release) through prevention barriers; the right side shows consequences following the top event through mitigation barriers. Widely used in process safety and major hazard risk management.
BBS (Behavior-Based Safety) A safety management approach focused on observing and modifying at-risk behaviors in the workplace. BBS programs involve structured observation of workers, feedback on safe and at-risk behaviors, and data collection to identify systemic behavioral patterns. Criticized when used to shift responsibility for safety from systems to individuals.
C
CAPA (Corrective and Preventive Action) A structured process for addressing the root causes of non-conformities (corrective action) and preventing potential non-conformities before they occur (preventive action). ISO 45001 Clause 10.2 requires a CAPA process for incidents and non-conformities. See: Corrective Action and CAPA Guide.
CCP (Critical Control Point) In HACCP food safety management, a step in the food production process at which a control measure can be applied to prevent or eliminate a food safety hazard or reduce it to an acceptable level. CCPs are monitored, and corrective actions must be taken when monitoring indicates a CCP is not under control.
Competence The ability to apply knowledge and skills to achieve intended results. ISO 45001 Clause 7.2 requires that persons doing work that affects OHS performance are competent — based on education, training, and/or experience. Competence is not the same as completing training; it requires demonstrated ability to perform the relevant task safely.
Confined Space An enclosed or partially enclosed space that is not designed primarily for human occupancy, has limited or restricted means of entry or exit, and has the potential to contain a hazardous atmosphere, engulfment material, or other recognized serious safety hazard. See: Confined Space Entry Guide.
Consequence The outcome of an incident in terms of its impact on people, assets, the environment, or organizational reputation. In risk assessment, consequence is one of the two dimensions of risk (the other being likelihood/probability).
Control Measure Any action, engineering modification, administrative procedure, or PPE that reduces or eliminates exposure to a hazard. Control measures are selected following the hierarchy of controls: elimination > substitution > engineering controls > administrative controls > PPE.
COSHH (Control of Substances Hazardous to Health) UK regulatory framework requiring employers to assess and control exposure to hazardous substances in the workplace. Equivalent requirements exist in most jurisdictions under national chemical safety legislation. A COSHH assessment identifies the substance, its hazards, how workers are exposed, and the controls required to protect them.
D
DART (Days Away, Restricted, or Job Transfer Rate) A US OSHA workplace injury and illness metric calculated as: (DART cases × 200,000) / total hours worked. A DART case is one that results in days away from work, restricted work, or job transfer. More sensitive than TRIR as it captures only more serious injuries and illnesses.
Due Diligence The reasonable steps taken by a person to avoid committing an offense or fulfilling a legal duty. In OHS, due diligence refers to the organizational and individual steps taken to identify and control workplace hazards, comply with OHS legislation, and demonstrate that the duty of care has been exercised.
E
Emergency Response Plan A documented plan describing how an organization will respond to emergency scenarios — fire, explosion, chemical spill, medical emergency, severe weather. ISO 45001 Clause 8.2 requires emergency preparedness and response planning that is commensurate with identified emergency scenarios.
Ergonomics The scientific study of the interaction between humans, systems, and the work environment, with the objective of optimizing human wellbeing and performance. Applied ergonomics in OHS focuses on designing work to fit the worker — reducing physical loading, awkward postures, and repetitive movements that contribute to musculoskeletal disorders. See: Workplace Ergonomics Guide.
F
Fatal Accident Rate (FAR) A risk measure expressing the number of fatalities expected per 100 million hours worked. Used in major hazard industries to compare occupational fatality risk between industries and job types. A FAR of 1 corresponds to approximately one fatality per 100 million hours worked.
Fine-Kinney Method A semi-quantitative risk assessment method calculating Risk Score = Probability × Exposure × Consequence. Each factor is scored on a structured scale; the resulting score places the risk in a band (from "negligible" to "very high") that determines the urgency and nature of required corrective action. Widely used in industrial OHS. See: Fine-Kinney Method Explained.
Frequency Rate A lagging safety metric expressing the number of recordable incidents per unit of hours worked (typically per million hours worked or per 200,000 hours worked). Not the same as TRIR — frequency rate typically refers to all recordable incidents, while TRIR uses a 200,000-hour basis equivalent to 100 workers.
G
GHS (Globally Harmonized System of Classification and Labelling of Chemicals) The UN international standard for classifying chemicals by health, environmental, and physical hazards, and for communicating hazard information through standardized labels and Safety Data Sheets (SDS). Implemented through OSHA HazCom in the US and CLP Regulation in the EU.
Good Manufacturing Practice (GMP) A set of regulations and guidelines ensuring that products (food, pharmaceuticals, cosmetics) are consistently produced and controlled to quality standards. In food production, GMP requirements address facility hygiene, pest control, equipment maintenance, and worker hygiene — overlapping with OHS management requirements.
H
HACCP (Hazard Analysis and Critical Control Points) A systematic preventive food safety approach addressing biological, chemical, and physical hazards in food production. HACCP is required under most food safety regulatory frameworks (EU 852/2004/EC, FDA FSMA, Codex Alimentarius). It is specifically focused on food safety hazards, not worker safety.
HAZOP (Hazard and Operability Study) A structured, systematic technique for hazard identification in process systems. A multidisciplinary team systematically applies guide words (More, Less, None, Reverse, etc.) to process parameters to identify deviations from design intent, their causes, and their consequences. The primary process safety hazard identification technique for complex chemical and process systems. See: HAZOP Study Guide.
Hazard A source with the potential to cause injury or ill-health. A hazard is distinct from risk — a chemical solvent on a shelf is a hazard; the risk is the probability and consequence of a worker being exposed to it. Hazard identification is the first step in risk assessment.
Hierarchy of Controls A ranked approach to controlling hazards, from most effective to least effective: (1) Elimination, (2) Substitution, (3) Engineering controls, (4) Administrative controls, (5) Personal protective equipment. A higher-level control is always preferred over a lower-level one.
Hot Work Any work involving ignition sources in areas where flammable or explosive materials may be present — welding, cutting, grinding, soldering. Hot work is typically controlled through a formal permit-to-work system. See: Permit to Work System.
I
Incident Any unplanned event resulting in, or having the potential to result in, injury, ill-health, or death. Incidents include both events that result in harm and near-miss events. ISO 45001 uses "incident" to encompass both — some organizations distinguish between incidents (with harm) and near misses (without harm).
Inherent Risk The level of risk before any controls or mitigation measures are applied. Residual risk is the level remaining after controls. The relationship between inherent and residual risk demonstrates the effectiveness of implemented controls.
J
Job Safety Analysis (JSA) / Job Hazard Analysis (JHA) A systematic process that breaks a task into individual steps, identifies hazards at each step, and determines control measures for each identified hazard. JSA/JHA is used before starting high-risk or unfamiliar tasks. See: JSA/JHA Guide.
Just Culture An organizational culture in which workers are encouraged and rewarded for providing safety-related information, with a clear distinction between acceptable behavior (including honest mistakes) and unacceptable behavior (deliberate violations). Just culture is a prerequisite for effective near-miss and incident reporting.
L
Lagging Indicator A safety metric that measures outcomes — events that have already happened (injuries, illnesses, incidents). Examples: TRIR, LTIR, DART. Lagging indicators reflect past performance; they do not predict future incidents. See: Leading vs Lagging Safety Indicators.
Leading Indicator A safety metric that measures conditions and behaviors that predict future safety outcomes — before incidents occur. Examples: near-miss reporting rate, inspection completion rate, corrective action closure rate, management safety walk frequency.
LEL (Lower Explosive Limit) The minimum concentration of a flammable gas or vapor in air that will ignite when exposed to an ignition source. Below the LEL, there is insufficient fuel for ignition. Above the UEL (Upper Explosive Limit), there is insufficient oxygen. The explosive range lies between LEL and UEL.
LOTO (Lockout/Tagout) A safety procedure used to ensure that dangerous machines are properly shut off and not able to be started up again until maintenance or servicing work is complete. LOTO involves physically locking energy isolators (circuit breakers, valves) and tagging them to prevent re-energization. Required by OSHA 29 CFR 1910.147. See: LOTO Guide.
LTIR (Lost Time Injury Rate) A lagging safety metric calculated as: (Lost time injuries × 200,000) / total hours worked. A lost time injury is one that results in at least one day away from work following the incident.
M
Management of Change (MoC) A formal process for evaluating and controlling the OHS implications of changes to processes, equipment, materials, procedures, and organizational structures before the change is implemented. Inadequate management of change is a leading contributor to major accidents in process industries.
MSD (Musculoskeletal Disorder) Work-related injuries and disorders affecting muscles, tendons, ligaments, nerves, and joints, caused or aggravated by work exposures — particularly repetitive motion, force, awkward posture, and vibration. The most common category of occupational illness in most industrialized countries.
N
Near Miss An unplanned event that did not result in injury, illness, or damage but had the potential to do so. Near misses are more frequent than incidents resulting in harm and provide the most valuable leading-indicator data for identifying systemic hazards. See: Near Miss Reporting Guide.
NIOSH Lifting Equation A tool developed by the National Institute for Occupational Safety and Health (US) for evaluating two-handed manual lifting tasks. Calculates the Recommended Weight Limit (RWL) and Lifting Index (LI) for specific lifting tasks, accounting for frequency, horizontal and vertical reach, trunk rotation, and coupling quality.
O
OEL (Occupational Exposure Limit) The concentration of a substance in workplace air at which most workers can be exposed without adverse health effects. OELs are typically expressed as Time-Weighted Averages (TWA) for 8-hour shifts and Short-Term Exposure Limits (STEL) for 15-minute periods. Not the same as safe thresholds — particularly for carcinogens and sensitizers.
OSHA (Occupational Safety and Health Administration) The US federal agency responsible for enforcing occupational safety and health regulations. OSHA sets and enforces standards, conducts inspections, and provides training and assistance. Key OSHA standards include: 29 CFR 1910 (general industry), 29 CFR 1926 (construction), and 29 CFR 1904 (recordkeeping).
P
P&ID (Piping and Instrumentation Diagram) A detailed engineering drawing showing the piping systems, instruments, and control systems in a process facility. P&IDs are the primary reference documents for HAZOP studies and process safety assessments.
PPE (Personal Protective Equipment) Equipment worn to minimize exposure to a hazard when other controls are insufficient. PPE is the lowest level of the hierarchy of controls — it does not eliminate the hazard, it reduces the worker's exposure to it. Examples: hard hats, safety glasses, gloves, high-visibility vests, respirators.
Permit to Work (PTW) A formal control system for managing high-risk work — typically hot work, confined space entry, electrical work, and work at height. A PTW specifies the work to be done, the hazards present, the controls required, and the authorization structure. See: Permit to Work System.
Process Safety Management (PSM) A regulatory framework (OSHA 29 CFR 1910.119) requiring systematic management of major accident hazards in facilities that handle highly hazardous chemicals above threshold quantities. Covers 14 elements including Process Hazard Analysis, Management of Change, Mechanical Integrity, and Emergency Planning.
Q
QRA (Quantitative Risk Assessment) A risk assessment method that uses numerical data to calculate risk levels in terms of frequency and consequence. QRA produces outputs such as individual risk (probability of fatality per year) and societal risk (F-N curves). Used primarily in major hazard industries. Distinct from qualitative and semi-quantitative approaches.
R
Reasonable Practicability The legal standard in OSHA law and many other jurisdictions — a control measure is "reasonably practicable" if its cost (money, time, effort) is not grossly disproportionate to the risk it reduces. The basis of the ALARP principle. The employer bears the burden of proving that a more protective control would not be reasonably practicable.
REBA (Rapid Entire Body Assessment) A posture-based ergonomic assessment tool used for tasks involving unpredictable, unstable, or dynamic postures. Scores posture of the trunk, neck, legs, upper arm, lower arm, and wrist; produces an action level (1–4) indicating the urgency of ergonomic intervention.
Residual Risk The level of risk remaining after all control measures have been applied. The goal of risk management is to reduce residual risk to ALARP, not necessarily to zero. Residual risk documentation forms part of the ALARP case.
Risk The combination of the probability of occurrence of a harm and the severity of that harm. Risk = Likelihood × Consequence (in its simplest form). Risk is the basis for deciding which control measures are required.
Risk Assessment The overall process of hazard identification, risk analysis, and risk evaluation. ISO 45001 Clause 6.1.2 requires a systematic risk assessment process covering all work-related hazards and changes to operations, equipment, and materials.
Root Cause Analysis (RCA) A systematic process for identifying the fundamental cause(s) of an incident — the causes that, if addressed, would prevent recurrence. Common RCA methods include 5 Whys, fishbone (Ishikawa) diagram, fault tree analysis, and bow-tie analysis. See: Root Cause Analysis Guide.
RULA (Rapid Upper Limb Assessment) A posture-based ergonomic assessment tool specifically for upper limb disorders in sedentary tasks. Assesses neck, trunk, leg, upper arm, lower arm, and wrist posture; produces an action level (1–4) indicating the urgency of ergonomic intervention.
S
Safety Climate Workers' perceptions of the organization's safety priorities at a specific point in time. Safety climate is distinct from safety culture — climate is perception-based and can be measured with surveys; culture is the underlying set of values and beliefs that drive behavior. Safety climate surveys (NOSACQ-50, HSMS) are widely used tools.
Safety Culture The shared values, assumptions, and behaviors that determine how safety is actually practiced in an organization. Safety culture is expressed in how workers behave when no one is watching, how management responds when safety and production conflict, and whether workers feel safe reporting concerns. See: Safety Culture Assessment.
SDS (Safety Data Sheet) A standardized document (16 sections under GHS) providing technical information about a chemical substance's hazards, physical properties, safe handling, storage, emergency response, and regulatory status. Required for all hazardous chemicals in workplaces under OSHA HazCom and equivalent regulations.
SFAIRP (So Far As Is Reasonably Practicable) An alternative expression of the ALARP standard, used in UK legislation and some management systems. ALARP and SFAIRP are equivalent.
SIMOPS (Simultaneous Operations) The management of multiple concurrent work activities in a shared area or on shared systems. SIMOPS coordination ensures that interactions between simultaneous activities (e.g., crane lifts adjacent to hot work) are identified and managed before they create uncontrolled hazards.
SIL (Safety Integrity Level) A measure of the performance required of a Safety Instrumented Function (SIF) to reduce risk to a tolerable level. Defined in IEC 61508 and IEC 61511. SIL 1 is the lowest level; SIL 4 is the highest. Widely used in process safety for Emergency Shutdown Systems and Safety Instrumented Systems.
T
Toolbox Talk A short, informal safety discussion held at the worksite before work begins — typically 5–15 minutes covering a specific safety topic relevant to the day's work. Also called tailgate meeting or safety briefing. See: Toolbox Talk Guide.
TRIR (Total Recordable Incident Rate) A lagging safety metric calculated as: (recordable incidents × 200,000) / total hours worked. A recordable incident under OSHA is one requiring medical treatment beyond first aid, resulting in restricted work or days away from work, or involving specific diagnosed conditions.
TWA (Time-Weighted Average) The average concentration of a substance in workplace air over an 8-hour work shift. Used in OEL standards to set exposure limits that apply to typical daily work schedules.
W
Work-Related Ill-Health A health condition caused by or worsened by work exposures. Work-related ill-health includes occupational diseases (caused by work) and work-aggravated diseases (pre-existing conditions worsened by work). Examples: noise-induced hearing loss, occupational asthma, MSD, work-related stress.
Z
Zero Harm A safety vision or goal expressing the aspiration of achieving zero workplace injuries, illnesses, and fatalities. While inspiring as a direction, zero harm is debated as a target — critics note that zero-target cultures can incentivize under-reporting rather than genuine risk reduction. Leading organizations use zero harm as a philosophical commitment while measuring progress with leading indicators.
How FindRisk Applies These Concepts
The terminology in this glossary reflects the integrated approach that effective OHS management requires: hazard identification, risk assessment, control implementation, monitoring, and continuous improvement.
FindRisk applies Fine-Kinney risk scoring, AI-assisted hazard identification, and structured corrective action tracking to the practical challenge of field-based safety inspection — translating these concepts into daily safety management.
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