Hazard identification and risk assessment: HIRA and JSA

In short

Hazard identification and risk assessment (HIRA) is the systematic process of finding everything in a workplace that can cause harm, judging how likely and how severe that harm is, ranking the results, and deciding what controls bring the risk down to an acceptable level. Job safety analysis (JSA), also called job hazard analysis, is the task-level version of the same logic: break a job into steps, list the hazards of each step, and fix controls for each hazard. HIRA is the mandatory first step of every safety management system — ISO 45001:2018 clause 6.1.2, the OSH&WC Code 2020 and its rules, the MSIHC Rules 1989 for hazardous chemical units, and every corporate safety audit protocol. It is examined in GATE-equivalent and university papers through risk matrices, risk scores, FMEA/RPN numbers and the hierarchy of control, and it is the single most asked topic in entry-level EHS interviews with Reliance, L&T, Tata Steel, Adani, Vedanta, ONGC, IOCL and construction and EPC contractors.

Explained

Basic vocabulary - get these exact

• Hazard: an inherent source, situation or act with potential to cause injury, ill-health, damage or loss (a 400 V bus bar, a 30 kg bag, benzene, a 3 m open edge).
• Hazardous event / release: the thing that happens when the hazard is realised (contact, fall, leak, fire, entanglement).
• Risk: combination of the likelihood of the hazardous event and the severity of its consequence. Risk = f(likelihood, severity). A hazard with no exposure pathway carries little risk.
• Exposure / frequency: how often and how long people, assets or the environment are in the hazard's reach. Many Indian scoring systems use it as a third factor.
• Consequence: the outcome - first aid, lost-time injury (LTI), fatality, ₹ loss, environmental damage, reputational loss.
• Risk assessment: the whole process of identifying hazards, analysing and evaluating risk, and comparing it against criteria.
• Risk analysis (estimate magnitude) versus risk evaluation (compare with tolerability criteria and decide if action is needed) - a common two-mark distinction.
• Inherent, initial and residual risk: inherent = with no control; initial = with existing controls; residual = after the additional controls you now propose.
• ALARP ("as low as reasonably practicable"): risk reduced until the cost or effort of further reduction is grossly disproportionate to the benefit. The tolerability triangle has an intolerable region at the top, a broadly acceptable region at the bottom and the ALARP region in between.
• Acceptable versus tolerable risk: acceptable needs no further action; tolerable is lived with only because it is ALARP and under review.
• Qualitative, semi-quantitative, quantitative: descriptive words; numeric scales multiplied into scores; and full QRA with failure frequencies (per year) and consequence modelling.

Hazard classification - the list examiners want

• Physical: noise, vibration, heat and cold stress, illumination, pressure, ionising and non-ionising radiation.
• Mechanical: rotating and in-running nip points, cutting and shearing, moving vehicles, stored energy, falling objects, work at height, confined space.
• Electrical: shock, arc flash and arc blast, static, induced voltage, lightning.
• Chemical: flammable, toxic, corrosive, oxidising, reactive, asphyxiant; routes of entry - inhalation, dermal, ingestion, injection.
• Fire and explosion: flammable atmospheres, dust explosion, BLEVE, vapour cloud - the detailed treatment belongs with fire and explosion hazards.
• Biological: bacteria, viruses, fungi, sewage and effluent handling, sharps.
• Ergonomic: manual handling, awkward posture, repetition, display screen work.
• Psychosocial: shift work, fatigue, workload, harassment, violence.
• Environmental and natural: flood, cyclone, seismic, lightning; plus organisational hazards - poor procedures, inadequate competence, change not managed.
• Hazards are also classified by energy type (energy-trace / barrier analysis): kinetic, potential, electrical, thermal, chemical, radiation, biological - and by whether they are routine, non-routine or emergency.

HIRA: the step-by-step method

1. Define scope and boundaries: plant, area, process, activity, project phase; include routine, non-routine, maintenance, commissioning, shutdown, emergency and contractor work, and people other than employees (visitors, nearby public).
2. Form the team: area in-charge, process/maintenance engineer, safety officer, a worker who actually does the job, plus a worker-representative member of the safety committee. Worker participation is a legal requirement for consultation and is what makes the output credible.
3. Collect inputs: P&IDs, layouts, SDS (safety data sheets), operating and maintenance procedures, incident and near-miss history, audit and inspection findings, hygiene monitoring data, equipment manuals, statutory test certificates, legal register.
4. Break the scope into activities: by process step, equipment, or job - the unit of entry in the HIRA worksheet.
5. Identify hazards for each activity using structured aids: walk-through survey, checklists, what-if questions, energy-trace, HAZID/HAZOP outputs, task observation, worker interviews.
6. Identify existing controls honestly - interlocks, guards, PPE, procedures, training, permits.
7. Assess likelihood and severity on the organisation's agreed scales and compute the risk score / band.
8. Evaluate against criteria: low / medium / high / extreme, with defined action and authority for each band.
9. Decide additional controls using the hierarchy of control; name an owner and a target date.
10. Re-score the residual risk with the proposed controls assumed in place and check it is acceptable.
11. Record in the risk register, approve, and communicate to everyone affected.
12. Implement, verify effectiveness, and review - periodically (commonly annually) and on triggers: process or plant change, new chemical or equipment, incident or near-miss, legal change, audit finding, new findings from monitoring.

JSA: the task-level method

• What it is: a documented, step-by-step breakdown of one job with hazards and controls against each step - the standard companion to a work permit for non-routine, high-risk or new jobs.
• When to do it: new or modified job, non-routine maintenance, job with a history of incidents, high-severity potential (height, confined space, hot work, excavation, lifting, energised work), job done by contractors, or a job where no written procedure exists.
• Selection priority: highest accident frequency and severity first, then high-potential jobs, then new jobs, then rarely performed jobs.
• Four classic steps: (1) select the job; (2) break it into sequential basic steps (usually 8-15; too few hides hazards, too many becomes a motion study); (3) identify the hazards and potential incidents of each step; (4) decide controls - eliminate, change procedure, change equipment, reduce frequency, add PPE.
• Write steps as action verbs - "open the isolation valve", "sling the load" - not as hazards or as controls.
• Involve the worker who does the job and validate by observing the job being done; get it reviewed and signed by the supervisor and safety officer.
• Three-column (step / hazard / control) is the common Indian format; four- and five-column versions add "potential consequence" and a risk rating per step, turning the JSA into a task-level HIRA.
• Related task-level tools: last-minute risk assessment (LMRA) or Take-5/point-of-work risk assessment done by the crew just before starting; toolbox talk to brief the JSA; safe work method statement (SWMS) in construction; permit to work as the control document.
• HIRA versus JSA: HIRA covers a whole facility or process and feeds the risk register and the SMS; JSA covers one job and feeds the permit, the SOP and the toolbox talk. JSA findings should be fed back into the facility HIRA.

Hazard identification techniques - and when each is right

• Checklist analysis: pre-set questions from codes and experience; fast, consistent, needs little expertise, but finds only what is already on the list.
• Safety walk-through / inspection survey: sees actual conditions and behaviour; depends on the observer's skill.
• What-if analysis: brainstormed "What if the pump stops? What if the valve is left open?"; flexible, good for simple or batch processes; unstructured, so completeness is not guaranteed. What-if / checklist combines both.
• Preliminary hazard analysis (PHA) / HAZID: early-design, coarse screening of major hazards and their broad controls before detail exists.
• FMEA / FMECA: equipment-oriented, bottom-up; for each component list failure modes, effects, causes, detection and ranks of Severity, Occurrence and Detection; RPN = S × O × D. Good for reliability and hardware; weak on human error and on multiple simultaneous failures.
• Fault tree analysis (FTA): deductive, top-down from an undesired top event through AND/OR gates to basic causes; gives the probability of the top event.
• Event tree analysis (ETA): inductive, forward from an initiating event through success/failure of each barrier to outcomes.
• Bow-tie: fault tree and event tree joined at a top event, showing threats, preventive barriers, consequences and mitigative barriers, with escalation factors - now the favourite management-level diagram.
• Cause-consequence and "Swiss cheese" / barrier models: show how holes in successive barriers line up.
• Task-based: JSA, hierarchical task analysis, human reliability analysis (HEART, THERP).
• Quantitative risk assessment (QRA): frequency (per year) × consequence modelling → individual risk per annum (IRPA), societal F-N curves, risk contours. Used for petroleum, LPG and chemical installations, and for PESO and consent approvals.
• HAZOP and the PSM elements are covered under process plant safety - in a HIRA context, note only that HAZOP is the deviation-based, node-by-node technique for continuous processes and is the main input to a process unit's risk register.

Risk estimation: scales, matrices and scoring

• Risk matrix: likelihood on one axis, severity on the other; usually 5 × 5, sometimes 3 × 3, 4 × 4 or 6 × 6. Cells are banded Low / Medium / High / Extreme (or green/yellow/orange/red). The scale definitions must be written down, or two assessors score the same hazard differently.
• Typical 5-point severity scale: 1 no injury/near miss, 2 first aid, 3 medical treatment or reportable injury, 4 lost-time injury or permanent disability, 5 single or multiple fatality. Parallel columns are usually defined for asset loss (₹) and environmental impact; score on the worst applicable column.
• Typical 5-point likelihood scale: 1 almost never (not in the industry), 2 unlikely (heard of elsewhere), 3 possible (has happened in the company), 4 likely (happens yearly at this site), 5 almost certain (happens monthly or more).
• Simple multiplicative score: R = L × S (1-25 on a 5 × 5).
• Three-factor / Fine-Kinney score: R = Consequence × Exposure × Probability - widely used in Indian HIRA formats because it rewards reducing exposure as well as probability.
• Action bands must be defined with authority and time: e.g. 1-4 low (maintain controls), 5-9 medium (action plan, area head), 10-15 high (stop or control before continuing, plant head), 16-25 extreme (stop work immediately, unit head approval to resume).
• Risk matrices are ordinal, not arithmetic: a score of 20 is not "twice as bad" as 10, and L × S can give the same number for a frequent minor event and a rare fatal one - which is why most matrices place any credible-fatality cell in a high band regardless of likelihood.
• Limitations: subjectivity and assessor bias, optimism about existing controls, risk-ranking reversals, no treatment of common-cause failure, and false comfort from a precise-looking number.

Hierarchy of control and risk treatment

1. Elimination - remove the hazard or the task (design out the need to work at height).
2. Substitution - replace with something less hazardous (toluene for benzene, water-based for solvent-based paint).
3. Engineering controls / isolation - enclosure, guarding, interlocks, local exhaust ventilation, intrinsically safe equipment, edge protection, relief and vent systems.
4. Administrative controls - safe operating procedures, permit to work, lockout-tagout, job rotation, training and competence, signage, limiting exposure time, maintenance schedules.
5. PPE - last line of defence; protects only the wearer, depends on fit, use and upkeep.
6. Why the order: the top controls do not rely on human behaviour and do not degrade; the bottom two fail silently. Many corporate standards show substitution combined with elimination and add "isolation/separation" as a separate level - the five-level list above is the usual exam answer.
7. Controls must also be checked for new hazards introduced (a guard that traps heat, an LEV that discharges into a walkway) and for reliability - a safety-critical control needs inspection, testing and a performance standard.
8. Interim controls are allowed while an engineering fix is being procured, and must be recorded with a date.

Indian legal and standards framework (as of November 2026)

• Occupational Safety, Health and Working Conditions Code, 2020 (OSH&WC Code) is in force from 21 November 2025 and subsumes the Factories Act 1948, the BOCW Act 1996, the Mines Act 1952, the Dock Workers Act and the other consolidated enactments. It carries forward the duties of the employer and occupier to provide a safe workplace, a risk-free working environment, and arrangements for assessment and control of hazards; safety committees and safety officers above notified thresholds; notification of dangerous occurrences and occupational diseases; and the hazardous-process regime with its mandatory disclosure of information to workers. Numerical thresholds and forms sit in the Central and State rules made under the Code, so quote the applicable State rule rather than a remembered Factories Act section.
• Manufacture, Storage and Import of Hazardous Chemical Rules, 1989 (under the Environment (Protection) Act 1986): mandatory safety report and on-site emergency plan for major accident hazard (MAH) installations above threshold quantities - effectively a legal requirement for QRA-grade risk assessment. Chemical Accidents (Emergency Planning, Preparedness and Response) Rules, 1996 set up crisis groups and the off-site plan.
• Public Liability Insurance Act 1991; Environment (Protection) Act 1986; Air and Water Acts; Explosives Act and Petroleum Act with PESO licensing; Static and Mobile Pressure Vessels (Unfired) Rules 2016; Gas Cylinders Rules 2016.
• Boilers Act, 2025 with the Indian Boiler Regulations, 2026 (in force October 2026, superseding IBR 1950); CEA (Measures relating to Safety and Electric Supply) Regulations, 2023 for electrical safety.
• Standards: IS/ISO 45001:2018 occupational health and safety management systems - clause 6.1.2 requires hazard identification and assessment of OH&S risks and clause 8.1.2 requires the hierarchy of control; IS 15656:2006 code of practice for hazard identification and risk analysis; IS 14489:1998 code of practice on occupational safety and health audit; IS 18001 was the earlier Indian OHSMS standard and has given way to IS/ISO 45001. International references used in Indian practice: ISO 31000:2018 (risk management principles), IEC 31010:2019 (risk assessment techniques - the catalogue of the methods listed above), ISO 17776 and ISO 12100 (machinery risk assessment).
• Sector practice: OISD standards (OISD-GDN-169, 206 and the audit guidelines) for oil and gas; DGMS circulars for mining; NDMA guidelines for chemical and industrial disaster risk; state factory inspectorate approval of safety reports; Directorate General, Factory Advice Service and Labour Institutes (DGFASLI) as the technical advisory body.

Key points

• Hazard - inherent potential to cause harm; risk - likelihood × severity of that harm being realised. Never swap them in an exam.
• HIRA scope - must cover routine, non-routine, maintenance, emergency and contractor activities and non-employees.
• HIRA is the entry point of ISO 45001 clause 6.1.2 and of every safety management system; it produces the risk register.
• JSA - step / hazard / control breakdown of one job; its unit is the job step, not the equipment.
• JSA four steps - select the job, break into steps, identify hazards, decide controls; written with the worker who does it.
• Hierarchy of control - elimination, substitution, engineering, administrative, PPE; PPE is the last resort, never the first answer.
• Risk matrix - defined likelihood and severity scales, banded cells, and a defined action and approval authority per band.
• R = L × S on a 5 × 5 matrix gives 1-25; Fine-Kinney R = C × E × P adds exposure explicitly.
• FMEA RPN = S × O × D - component-level, bottom-up; high RPN or high severity alone triggers action.
• FTA is deductive and top-down; ETA is inductive and forward; bow-tie joins the two at the top event.
• Residual risk - re-scored after proposed controls; it must fall in an acceptable band, and the assessment is not closed until it does.
• ALARP - keep reducing until further reduction costs grossly disproportionate effort; the basis of "tolerable" risk.
• Review triggers - change of plant, process, chemical, law or personnel; any incident or near-miss; periodic (typically annual) review.
• Worker participation and competence are legal and practical requirements - a HIRA written in an office by one person is the classic audit non-conformity.
• MSIHC Rules 1989 make a safety report and on-site emergency plan mandatory for MAH installations - the legal hook for QRA in India.
• IS 15656 (hazard identification and risk analysis), IS/ISO 45001:2018, ISO 31000 and IEC 31010 are the standards to name.
• Risk matrices are ordinal - do not average scores across hazards or claim a score is proportionally worse.
• OSH&WC Code 2020 (in force 21 November 2025) is the governing statute; the repealed Factories Act 1948 may be named only as the former law.

Formulas and examples

Example 1 - 5 × 5 matrix, initial and residual risk. A 25 kg bag of additive is manually lifted from floor level to a 1.4 m hopper, 180 times per shift.

• Hazards: back injury from manual handling; dust inhalation at the hopper mouth.
• Manual handling: severity 3 (medical treatment, reportable back injury), likelihood 4 (back complaints occur yearly at the site) → R = 3 × 4 = 12 → High band (10-15). Action required before continuing.
• Controls proposed: supply the additive in 500 kg big bags handled by a hoist (engineering), plus a platform to remove the lift height (engineering). New severity 2, new likelihood 2 → residual R = 4 → Low.
• RRF = 12 / 4 = 3; % reduction = (1 − 4/12) × 100 = 66.7%.
• Dust: severity 3, likelihood 3 → R = 9 → Medium; with local exhaust ventilation at the hopper and an FFP2 respirator as interim control, likelihood drops to 1 → residual R = 3 → Low.

Example 2 - Fine-Kinney score for hot work on a tank farm pipeline.

• Consequence C = 40 (multiple fatality / major fire credible), Exposure E = 2 (occasionally - a few times a year), Probability P = 1 (conceivable but unlikely with permit controls).
• R = 40 × 2 × 1 = 80. On the standard Fine-Kinney bands (20-70 possible risk, attention needed; 70-200 substantial risk, correction needed) 80 is substantial - correction required.
• After adding a gas test every 2 hours, a fire watch, and a hot-work permit countersigned by the shift in-charge, P falls to 0.5 → R = 40 × 2 × 0.5 = 40, in the "possible risk, attention needed" band. Note that C cannot be reduced by procedures - only by eliminating hot work (cold cutting) or draining and gas-freeing the line, which is why the preferred answer is elimination.

Example 3 - FMEA / RPN on a centrifugal pump mechanical seal.

• 9 × 4 × 5 = 180; 7 × 3 × 3 = 63; 5 × 5 × 2 = 50; 9 × 2 × 6 = 108. Priority by RPN: seal wear (180) → gasket (108) → bearing (63) → coupling (50).
• Actions: seal-leak detection and a seal-pot level alarm cut D from 5 to 2 → RPN = 9 × 4 × 2 = 72; adding a double seal with barrier fluid cuts O from 4 to 2 → RPN = 9 × 2 × 2 = 36.
• Caution: severity 9 items must be acted on even at low RPN - the gasket item (RPN 108) and any fatality-capable mode get action on severity alone.

Example 4 - fault tree and expected loss for a conveyor guard. A nip-point injury needs (a) the guard to be missing or defective AND (b) a person to reach into the nip.

• P(guard defective) = 0.05 per year of operation; P(reach-in given defective guard) = 0.2 → AND gate: P(injury) = 0.05 × 0.2 = 0.01 per year (once in 100 years).
• Loss per event (treatment, compensation under the employees' compensation provisions, lost production, investigation) estimated at ₹12,00,000 → EML = 0.01 × 12,00,000 = ₹12,000 per year.
• A fixed interlocked guard costing ₹45,000 with ₹3,000 per year upkeep removes essentially all of this. Payback on EML alone looks poor (₹12,000 against ₹45,000 + ₹3,000/yr) - the decision is still to fit the guard, because a credible-permanent-disability consequence sits in the intolerable region and statutory guarding of machinery is not a cost-benefit choice. This is precisely the ALARP argument, and a favourite interview trap.

Example 5 - FAR for a construction site. 1,200 workers × 8 hours/day × 300 days = 28,80,000 (2.88 × 10⁶) exposed hours in a year, with 2 fatalities.

• FAR = (2 / 2.88 × 10⁶) × 10⁸ = 69.4 fatalities per 10⁸ hours. Indian construction typically scores far worse than process industry benchmarks (often around 1-2), which is why work at height, excavation and lifting dominate construction JSAs.

Comparison table

Where it is used

• Refineries, petrochemicals and fertiliser plants (IOCL, BPCL, RIL, GAIL, Tata Chemicals, Coromandel): HIRA registers per unit, MSIHC safety report, OISD audits, hot-work and confined-space JSAs with permits.
• Steel, cement, mining and smelters (Tata Steel, JSW, SAIL, Hindalco, UltraTech, Coal India): HIRA of material handling, furnace and crane operations; JSA for shutdown and relining jobs; DGMS-driven risk assessment in mines under the OSH&WC regime.
• Construction and EPC (L&T, Shapoorji Pallonji, Afcons, metro and expressway projects): activity-wise HIRA at the method-statement stage, daily JSA/SWMS and toolbox talks for height, excavation, lifting and energised work; a contractual deliverable in most tenders.
• Power, renewables and transmission (NTPC, Adani Green, Tata Power): HIRA for boiler and turbine areas, LOTO-based JSAs, arc-flash risk assessment under the CEA Safety Regulations 2023.
• Pharma, FMCG, automotive and warehousing (Sun Pharma, Cipla, Hindustan Unilever, Maruti, Flipkart/Amazon fulfilment): ISO 45001 HIRA registers, ergonomic and machine-guarding assessments, forklift and racking risk assessment.
• Job roles: safety officer / EHS executive (HIRA and JSA ownership), process safety engineer, risk analyst in consultancies (DNV, ERM, TUV, Cholamandalam MS Risk Services), insurance risk surveyor, third-party safety auditor under IS 14489, and government factory and labour inspectors.

Interview questions

• Q: Difference between hazard and risk? A: A hazard is the inherent potential to cause harm; risk is the combination of how likely that harm is and how severe it would be. Petrol in a sealed drum is a hazard with low risk; the same petrol being decanted near a grinder is high risk.
• Q: What are the steps of a HIRA? A: Define scope, form a competent team with worker participation, gather information, list activities, identify hazards, record existing controls, rate likelihood and severity, evaluate against risk criteria, add controls by the hierarchy, re-score residual risk, record and approve, then implement, verify and review.
• Q: How is JSA different from HIRA? A: JSA is task-level - one job broken into steps with hazards and controls per step, usually attached to a permit; HIRA is wider, covering an area, process or whole facility, and feeds the organisation's risk register.
• Q: State the hierarchy of control with an example of each. A: Elimination (cold cutting instead of hot work), substitution (water-based paint for solvent-based), engineering (interlocked guard, LEV), administrative (permit to work, LOTO, training), PPE (respirator, harness).
• Q: Why is PPE the last control? A: It does not remove the hazard, protects only the wearer, and depends entirely on correct selection, fit, use and maintenance - it fails silently and at the worst moment.
• Q: When would you re-do a risk assessment? A: On any change of plant, process, chemical, method, law or key personnel; after an incident or significant near-miss; on an audit or monitoring finding; and at the defined periodic review, commonly annual.
• Q: What does ALARP mean and who decides it? A: Risk reduced to a point where further reduction would cost effort or money grossly disproportionate to the benefit gained; the duty holder decides and must be able to justify it with evidence, not assert it.
• Q: Two hazards both score 12 - one is a frequent minor injury, the other a rare fatality. Which do you act on first? A: The fatality potential, because risk matrices are ordinal and a credible-fatality consequence is not offset by low likelihood; most matrices and corporate rules escalate high-severity cells regardless of score.
• Q: What is residual risk and what do you do if it stays high? A: The risk remaining after the proposed controls; if it is still in a high or extreme band the activity must not proceed - you go back up the hierarchy, change the method, or eliminate the task.
• Q: What is RPN in FMEA and its weakness? A: RPN = Severity × Occurrence × Detection on 1-10 scales; its weakness is that the product can hide a high-severity mode behind low occurrence and good detection, so severity must be screened separately.
• Q: Which Indian legal provisions drive risk assessment? A: The OSH&WC Code 2020 and its rules (employer duty to provide a risk-free workplace, safety committees, safety officers, hazardous processes), the MSIHC Rules 1989 (safety report and on-site emergency plan for MAH installations), and the Chemical Accidents Rules 1996 for off-site planning; IS/ISO 45001:2018 and IS 15656 are the standards used.
• Q: Who should write a JSA? A: The supervisor together with the workers who actually do the job, reviewed by the safety officer and verified by watching the job performed - not drafted alone at a desk.
• Q: How do you identify hazards in a brand-new plant with no incident history? A: Use design-stage techniques - HAZID/PHA, HAZOP, checklists against codes, SDS and vendor hazard data, energy-trace analysis, and incident experience from similar plants and industry databases.

Common mistakes

• Using "hazard" and "risk" interchangeably, or writing a control in the hazard column of a HIRA worksheet.
• Writing JSA steps as hazards or as instructions to be careful ("be alert", "take care") - steps must be actions, controls must be specific and verifiable.
• Jumping straight to PPE and training as controls and skipping elimination, substitution and engineering.
• Scoring with undefined scales, or changing the severity to make a score land in a comfortable band; scoring existing controls as if they were already perfect.
• Forgetting non-routine work - start-up, shutdown, cleaning, breakdown maintenance, confined-space entry, and contractor activity - which is where most serious incidents happen.
• Leaving residual risk un-scored, or scoring it with controls that have no owner, no date and no verification of effectiveness.
• Treating the HIRA document as the deliverable - a register that is not communicated to workers, trained out and reviewed on change is an audit non-conformity and legally indefensible.
• Quoting repealed law - citing Factories Act 1948 sections instead of the OSH&WC Code 2020 and the applicable State rules, or withdrawn IS numbers.

Related topics

Process plant safety: HAZOP and PSM · Safety instrumented systems · Fire, explosion and toxic release hazards · Construction safety · Industrial safety and maintenance · Electrical safety and earthing