NEBOSH IDip cheat sheet

Hierarchy of control (ISO 45001 order): eliminate the hazard, substitute, engineering controls, administrative controls, then PPE - PPE is the last line of defence and protects only the wearer.

PDCA underpins ISO 45001: Plan (context, leadership, planning, hazard identification), Do (support, operation), Check (performance evaluation), Act (improvement); certification is by third-party audit, not by the standard itself.

Reasonably practicable (UK/IDip framing): risk is weighed against the sacrifice (time, trouble, cost) needed to control it; gross disproportion applies - cost must be grossly disproportionate to the risk reduction before it justifies inaction.

ALARP decision rule: if risk is below the broadly acceptable level, no further action is needed; if above the tolerable level, reduce it; between them, reduce unless cost is grossly disproportionate to benefit.

Accident ratio (Bird's triangle): for every serious injury there are roughly 10 minor injuries and 30 property-damage incidents and 600 near misses - investigate near misses because they signal failure before harm.

Active (proactive) monitoring measures compliance and control before loss (inspections, audits, exposure monitoring); reactive monitoring measures failure after loss (accidents, incidents, ill health, near misses, complaints).

Root-cause analysis (5 Whys, fault tree, Ishikawa) distinguishes immediate causes (unsafe acts/conditions) from underlying and root causes (management system failures such as no training, no maintenance, poor design).

Safety culture maturity (Hudson/DuPont): pathological (who cares), reactive (we react to incidents), calculative (we have systems), proactive (we anticipate), generative (H&S is how we do business) - leadership behaviour, not documentation, drives maturity.

Risk = likelihood × severity (consequence); a risk assessment must record the hazard, who is exposed, existing controls, the residual risk rating and the further action required with an owner and date.

Fire tetrahedron: fuel, oxygen, heat, and (for chain reaction) chemical reaction; removal of any one side extinguishes the fire. Fire classes: A solids, B liquids, C gases, D metals, F cooking oils.

DSEAR/ATEX logic: a flammable atmosphere needs concentration between the lower and upper explosive limits (LEL/UEL) and an ignition source above the minimum ignition energy; control by eliminating ignition sources, inerting, ventilation and containment.

Noise: action values are 80 dB(A) lower and 85 dB(A) upper (daily/weekly exposure), with peak limits 135 dB(C) and 137 dB(C); hearing protection is PPE and only valid after noise reduction at source.

HAVS (hand-arm vibration): exposure is A(8) in m/s²; action value 2.5 m/s² A(8), limit value 5 m/s² A(8); control by low-vibration tools, trigger-time limits, warm hands, health surveillance.

Manual handling risk assessment (TILE): Task, Individual, Load, Environment - each factor modifies the risk independently of the load weight alone.

Confined space: oxygen deficiency/enrichment, toxic gas, flammable atmosphere and engulfment are the four main hazards; entry requires permit, atmospheric testing, rescue plan and non-entry rescue where practicable.

COSHH/chemical control hierarchy: eliminate, substitute, enclose, local exhaust ventilation (LEV) at source, then general ventilation; RPE (respiratory protective equipment) only with face-fit testing, and it does not protect others.

Machine safety: guards must prevent access to dangerous parts (fixed, interlocked, adjustable, self-adjusting); interlocks must fail safe, and emergency stops are complementary, not a substitute for guarding.

Practical assessment structure: a management report (typically ~3,000 words) plus a hazard observation/risk assessment exercise; marks are awarded for identification, justification, prioritisation and realistic action planning, not for prose length.

Observation technique: walk the site systematically (process flow, not random), record what is seen and where, and link each observation to a specific hazard category and a legal/standards reference.

Risk rating rule: assign likelihood × severity from a stated matrix, then rank actions by risk - high risk first, with target date, responsible person and interim controls where the permanent fix takes time.

Cost-benefit justification: quantify the risk reduction, compare with the cost of control, and state whether the cost is grossly disproportionate; cite the reasonably practicable test to defend the recommendation.

SMART actions: Specific, Measurable, Achievable, Relevant, Time-bound; an action without an owner and a date is not a control and loses marks.

Report structure: executive summary, scope and methodology, findings (with evidence), risk assessment table, prioritised action plan, conclusions and recommendations to top management.

Strengths and weaknesses of the organisation's own management system (e.g. against ISO 45001 clauses: leadership, consultation, planning, support, operation, evaluation, improvement) should be evidenced by the observations, not asserted.

Weakness analysis: distinguish individual (behaviour, competence), job (task design, procedures) and organisational (culture, resources, priorities) factors - the last usually carries the highest leverage.

Continuing professional development (CPD): record planned and unplanned learning, reflect on what changed in practice, and evidence it against a competence framework; output matters more than hours logged.

Professional codes of conduct typically require: competence within one's limits, honesty and integrity, confidentiality, avoiding conflicts of interest, reporting serious risk to those who can act, and not misrepresenting qualifications.

Whistleblowing decision rule: first raise internally through the line or a designated channel; if the risk is serious and imminent and internal channels fail, escalate externally (regulator) - protect evidence and record the timeline.

Competence is a combination of knowledge, skills, experience and behaviour; a qualification alone does not demonstrate competence for a specific task.

Ethical dilemma test: is it legal, is it consistent with the code, who is harmed, would I defend it publicly, and what would a reasonable professional do? Document the reasoning.

Negotiation with management: frame H&S in business language (cost of incidents, downtime, insurance, reputation) and present options with costs, not single demands.

Mentoring and supervision: a mentor provides guidance and challenge but accountability for decisions remains with the practitioner; supervision is a formal, recorded relationship.

Reflective practice (Gibbs cycle): description, feelings, evaluation, analysis, conclusion, action plan - the action plan is what turns experience into competence.