56  Industrial Accidents and Safety: Definition, Heinrich’s Domino, Bird’s Pyramid, Causes (Unsafe Acts / Conditions), Frequency and Severity Rates, Safety Programmes, Statutory Safety (Sections 21-41 Factories Act), Safety Committee, Safety Officer, Disaster Management and the OSH&WC Code 2020

56.1 Safety as a Line Function

An industrial accident is an unplanned event in the course of work that interrupts the orderly progress of activity and may cause injury, ill-health, damage or loss. Safety is now seen not as a “staff function” delivered by a safety department but as a line function of every supervisor and worker. The legal framework runs from Sections 21-41 of the Factories Act 1948 and the Mines Act 1952 through the Employees’ Compensation Act 1923 (compensation), the ESI Act 1948 (disablement benefit) to the modern OSH&WC Code 2020.

56.2 1 · Concept and Definitions

TipDefinitions
Source Substance
ILO An accident is an unexpected and unplanned occurrence which interrupts an orderly progress of activity
Heinrich (1931) An unplanned and uncontrolled event in which the action or reaction of an object, substance, person, or radiation results in personal injury or the probability thereof
Factories Act / Mines Act Accident causing death, bodily injury or loss; reporting obligation under Section 88 of Factories Act
NotePYQ trap — Heinrich’s 1:29:300 Pyramid

Heinrich’s 1931 study of 75,000 industrial accidents proposed the 1:29:300 ratio — for every 1 major injury, there are 29 minor injuries and 300 no-injury near-misses. The triangle is foundational to modern safety thinking.

56.3 2 · Theories of Accident Causation

TipMajor Theories
Theory Substance
Heinrich’s Domino (1931) Five-domino sequence: social environment → fault of person → unsafe act/condition → accident → injury. Remove unsafe act → no accident
Bird and Loftus (1976) — Updated Domino Five dominoes: lack of management control → basic causes → immediate causes → incident → loss
Bird’s Triangle (1969) 1 serious : 10 minor : 30 property damage : 600 near-misses
Reason’s Swiss Cheese (1990) Multiple defensive layers, each with holes — accident occurs when holes align
Multiple Causation Most accidents have many contributing factors — no single cause
Human Factor / Psychological Unsafe acts due to inattention, fatigue, attitude
Pure Chance Random, statistical occurrence
Energy Release Accident = unwanted release of energy (Haddon)

56.4 3 · Causes of Accidents

TipTwo Categories of Direct Causes
Category Examples
Unsafe Acts (≈ 88 % per Heinrich) Working without authority, failure to warn, working at improper speed, using defective equipment, removing safety devices, distraction, horseplay, lifting improperly
Unsafe Conditions (≈ 10 % per Heinrich) Defective tools, inadequate guarding, poor housekeeping, defective design, hazardous arrangement, inadequate illumination, ventilation
Acts of God / Inherent (≈ 2 %) Lightning, earthquake, etc.

56.5 4 · Measurement of Industrial Accidents

TipStandard Accident Indices
Index Formula Substance
Frequency Rate (No. of disabling injuries × 1,000,000) ÷ Total man-hours worked Frequency per million man-hours
Severity Rate (No. of man-days lost × 1,000,000) ÷ Total man-hours worked Days lost per million man-hours
Incidence Rate (No. of injuries × 1,000) ÷ Average number of workers Per 1,000 workers
Accident Cost Direct (medical, compensation) + Indirect (downtime, recruitment, damage, reputation)
Heinrich’s iceberg Indirect costs ≈ 4 times direct costs

56.6 5 · Safety Programme

A comprehensive safety programme typically includes:

  • Safety policy signed by top management.
  • Safety committee with worker and management representatives.
  • Safety officer (statutory).
  • Workplace inspection and hazard reporting.
  • Job safety analysis (JSA).
  • Permit-to-work system.
  • Training — induction, on-the-job, refresher.
  • PPE programme.
  • Emergency preparedness — fire, evacuation, mutual aid.
  • Accident investigation and follow-up.
  • Safety promotion — posters, awards, campaigns.
  • Management review.

56.7 6 · Statutory Safety — Factories Act 1948 (Sections 21-41)

TipKey Safety Provisions
Section Provision
21 Fencing of machinery
22 Work on or near machinery in motion
23 Prohibition of employment of young persons on dangerous machines
24 Striking gear and devices for cutting off power
25 Self-acting machines
26 Casing of new machinery
27 Prohibition of women / children near cotton openers
28 Hoists and lifts
29 Lifting machines, chains, ropes
30 Revolving machinery
31 Pressure plant
32 Floors, stairs and means of access
33 Pits, sumps, openings in floors
34 Excessive weights
35 Protection of eyes
36 Precautions against dangerous fumes, gases
36A Precautions in respect of portable electric light
37 Explosive or inflammable dust, gas
38 Precautions in case of fire
39 Power to require specifications of defective parts
40-40A Safety of buildings and machinery
40B Safety Officer — required where 1,000+ workers
41 Power to make rules
NotePYQ anchor — Safety Officer at 1,000+ workers

Section 40B requires a Safety Officer in factories employing 1,000 or more workers (or as may be notified for hazardous processes irrespective of number).

56.8 7 · Chapter IV-A — Hazardous Processes (Sections 41A-41H)

Added by 1987 amendment post-Bhopal disaster (1984) — special provisions for hazardous processes:

  • 41A — Site Appraisal Committee.
  • 41B — Compulsory disclosure of information by occupier.
  • 41C — Specific responsibility of occupier in relation to hazardous processes.
  • 41D — Central government power to appoint Inquiry Committee.
  • 41E — Emergency standards.
  • 41F — Permissible limits of exposure of chemical and toxic substances.
  • 41G — Worker’s participation in safety management; Safety Committee.
  • 41H — Right of workers to warn about imminent danger.

56.9 8 · Safety Committee — Section 41G

A Safety Committee with equal representation of workers and management is mandatory for factories with hazardous processes. It reviews safety performance and recommends improvements.

56.10 9 · Disaster Management

After Bhopal (1984), India developed a multi-tier framework:

  • Manufacture, Storage and Import of Hazardous Chemicals Rules 1989 (under Environment Protection Act 1986).
  • Public Liability Insurance Act 1991 — no-fault liability for hazardous-industry accidents.
  • National Environment Tribunal Act 1995.
  • Disaster Management Act 2005 — set up NDMA, SDMA, DDMA.
  • National Disaster Management Plan 2019.

56.11 10 · Position under the OSH&WC Code 2020

The Code consolidates safety provisions of the Factories Act, Mines Act, Plantations Act, Building & Other Construction Workers Act, Contract Labour Act and ISMW Act. Key features:

  • National OSH Advisory Board.
  • Safety committees required by notification.
  • Free annual health check for workers above 45.
  • Appointment letters mandatory.
  • Enhanced penalties for fatal accidents.

56.12 11 · Indian Safety Performance — Selected Numbers

  • ESI Corporation processes ≈ 30,000-40,000 disablement claims annually.
  • DGMS reports ≈ 100-150 fatalities per year in mines.
  • DGFASLI reports thousands of factory accidents (non-fatal majority).
  • Construction sector — high under-reporting; ILO estimates 38 fatal per 100,000 workers globally.

56.13 12 · Indian Standards and Codes

  • IS 14489 — Code of Practice on Occupational Safety and Health Audit.
  • IS 18001 / OHSAS 18001 → ISO 45001 (2018) — Occupational Health and Safety Management Systems — global voluntary standard.

56.14 Practice Questions

Q 01HeinrichMedium

Heinrich's accident ratio 1:29:300 refers to:

  • AMajor injuries : minor injuries : near-misses
  • BFatal : permanent : temporary
  • CWorkers : supervisors : managers
  • DStrike : lockout : layoff
View solution
Correct Option: A
1 major : 29 minor : 300 no-injury near-misses.
Q 02DominoMedium

Heinrich's Domino Theory has how many dominoes?

  • A3
  • B4
  • C5
  • D7
View solution
Correct Option: C
Five dominoes.
Q 03Safety OfficerMedium

A Safety Officer is required under Section 40B of the Factories Act for factories employing:

  • A100+ workers
  • B500+ workers
  • C1,000+ workers
  • D5,000+ workers
View solution
Correct Option: C
1,000 or more workers.
Q 04Section 41GHard

A Safety Committee under Section 41G has:

  • AOnly management representatives
  • BOnly worker representatives
  • CEqual representation of workers and management
  • DOutside experts only
View solution
Correct Option: C
Equal representation.
Q 05Frequency RateHard

Frequency Rate of injuries =

  • ADays lost × 1,000 ÷ Workers
  • BInjuries × 1,000,000 ÷ Man-hours worked
  • CInjuries ÷ Workers
  • DCompensation ÷ Workers
View solution
Correct Option: B
Per million man-hours.
Q 06BhopalHard

Chapter IV-A on hazardous processes was added to the Factories Act after the:

  • AChasnala mine disaster (1975)
  • BBhopal gas tragedy (1984)
  • CJaipur tanker fire (2009)
  • DVizag styrene leak (2020)
View solution
Correct Option: B
1987 amendment after Bhopal 1984.
Q 07Swiss CheeseHard

The "Swiss Cheese" model of accidents is associated with:

  • AHeinrich
  • BBird
  • CReason
  • DHaddon
View solution
Correct Option: C
James Reason 1990.
Q 08Unsafe actsMedium

Per Heinrich, unsafe acts account for approximately:

  • A10 %
  • B50 %
  • C88 %
  • D2 %
View solution
Correct Option: C
88 % unsafe acts; 10 % unsafe conditions; 2 % unavoidable.
Q 09IcebergMedium

Per Heinrich's iceberg, indirect accident costs are approximately:

  • AEqual to direct costs
  • BTwice direct costs
  • CFour times direct costs
  • DHalf of direct costs
View solution
Correct Option: C
4 × direct costs (1:4 ratio).
Q 10Section 21Easy

Fencing of machinery is covered under:

  • ASection 11
  • BSection 21
  • CSection 32
  • DSection 49
View solution
Correct Option: B
Section 21 — fencing of machinery.
Q 11Right to warnHard

Workers' right to warn about imminent danger is in:

  • ASection 21
  • BSection 41H
  • CSection 88
  • DSection 96A
View solution
Correct Option: B
Section 41H.
Q 12PLIHard

The Public Liability Insurance Act provides:

  • ANo-fault liability for accidents in hazardous industries
  • BCompulsory insurance for vehicles only
  • CDirector liability insurance
  • DProperty insurance
View solution
Correct Option: A
1991 Act — no-fault liability.
Q 13ISO 45001Medium

ISO 45001 is a global standard on:

  • AQuality management
  • BEnvironmental management
  • COccupational health and safety management
  • DInformation security
View solution
Correct Option: C
OHSMS — published 2018.
Q 14EnergyHard

The "energy release" model of accidents is associated with:

  • AHeinrich
  • BBird
  • CHaddon
  • DReason
View solution
Correct Option: C
Haddon — unwanted release of energy.
Q 15SequenceHard

Arrange Heinrich's dominoes in correct order:

  • AInjury → Accident → Unsafe act → Fault of person → Social environment
  • BSocial environment → Fault of person → Unsafe act/condition → Accident → Injury
  • CAccident → Injury → Social → Fault → Unsafe
  • DUnsafe → Social → Fault → Injury → Accident
View solution
Correct Option: B
Five-domino sequence.
Q 16SeverityHard

Severity Rate measures:

  • ANumber of injuries
  • BDays lost per million man-hours
  • CWorkers' compensation cost
  • DNumber of near-misses
View solution
Correct Option: B
Man-days lost ratio.
Q 17BirdHard

Bird's revised triangle (1969) ratio is approximately:

  • A1 : 10 : 30 : 600
  • B1 : 29 : 300
  • C1 : 4 : 16
  • D1 : 100 : 1000
View solution
Correct Option: A
1 serious : 10 minor : 30 property : 600 near-misses.
Q 18HazardousHard

Site Appraisal Committee under Section 41A reviews:

  • AAll factory licences
  • BInitial location and safety of hazardous-process factories
  • CWelfare measures
  • DWage rates
View solution
Correct Option: B
Site appraisal for hazardous units.
Q 19DMA 2005Medium

The Disaster Management Act came in:

  • A1995
  • B2002
  • C2005
  • D2010
View solution
Correct Option: C
2005 — NDMA, SDMA, DDMA framework.
Q 20Code 2020Easy

Safety provisions of the Factories Act 1948 are now consolidated in:

  • ACode on Wages 2019
  • BCode on Social Security 2020
  • COSH&WC Code 2020
  • DIR Code 2020
View solution
Correct Option: C
OSH&WC Code 2020.

56.15 Quick Recall

ImportantQuick recall
  • Heinrich (1931): 1:29:300 pyramid; 88 % unsafe acts / 10 % unsafe conditions / 2 % unavoidable; indirect costs 4 × direct.
  • Theories: Domino (Heinrich), Updated Domino (Bird-Loftus 1976), Bird’s Triangle (1:10:30:600), Swiss Cheese (Reason 1990), Energy Release (Haddon), Multiple Causation.
  • Indices: Frequency Rate (× 10⁶ ÷ man-hours); Severity Rate (days lost × 10⁶ ÷ man-hours); Incidence Rate (× 1,000 ÷ workers).
  • Factories Act Safety: Sections 21-41 + Chapter IV-A (Sections 41A-41H — post-Bhopal 1987 amendment).
  • Safety Officer — Section 40B — 1,000+ workers.
  • Safety Committee — Section 41G — equal worker-management representation.
  • 41H — Workers’ right to warn of imminent danger.
  • Bhopal-driven reforms: Hazardous Chemicals Rules 1989; Public Liability Insurance Act 1991; National Environment Tribunal Act 1995; Disaster Management Act 2005.
  • OSH&WC Code 2020 consolidates safety regime; annual free check-up for 45+.
  • Global standard: ISO 45001 (2018) — OHS management systems.