Labour Welfare II: Industrial Health and Hygiene, Industrial Accidents and Safety, and Occupational Diseases

The Joint ILO/WHO Committee on Occupational Health (1950, revised 1995) defined the aims of occupational health as the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations; the prevention among workers of departures from health caused by their working conditions; the protection of workers in their employment from risks resulting from factors adverse to health; and the placing and maintenance of the worker in an occupational environment adapted to his physiological and psychological capabilities — in short, the adaptation of work to man and of each man to his job. Occupational health services put this into practice through pre-employment and periodic medical examinations, the surveillance of the work environment and of workers' health, first aid and emergency care, health education, advice on ergonomics and the placement of workers with disabilities, and records. In India the Factories Act's hazardous-process chapter requires medical examination of workers in hazardous processes and health records, section 87 empowers rules for dangerous operations, the ESI scheme provides medical care, and the Directorate General, Factory Advice Service and Labour Institutes (DGFASLI) and its regional labour institutes study occupational health and train factory medical officers.

Industrial (occupational) hygiene is the science and art devoted to the anticipation, recognition, evaluation and control of environmental factors or stresses arising in or from the workplace that may cause sickness, impaired health or significant discomfort among workers. Hazards are grouped as physical (noise, vibration, heat and cold, ionising and non-ionising radiation, poor lighting, abnormal pressure), chemical (dusts, fumes, gases, vapours, mists and liquids, entering by inhalation, skin absorption or ingestion), biological (bacteria, viruses, fungi and parasites, as among health-care, agricultural and sewage workers), ergonomic (awkward postures, repetitive motion, manual lifting) and psychosocial (shift work, workload, harassment and stress). Exposure is evaluated by measuring concentrations and comparing them with exposure limits — the permissible limits of exposure in the Second Schedule of the Factories Act, or threshold limit values of the kind published by the American Conference of Governmental Industrial Hygienists.

An industrial accident is an unplanned, unexpected event arising out of and in the course of employment that causes or could cause injury or damage. The Factories Act requires notice of any accident that causes death, or bodily injury that prevents the injured person from working for forty-eight hours or more immediately following it (section 88), and of dangerous occurrences whether or not anyone is hurt (section 88A). H. W. Heinrich's Industrial Accident Prevention (1931) framed the classic account. His domino theory arranged five factors in sequence — ancestry and social environment, fault of the person, an unsafe act or unsafe condition, the accident, and the injury — so that removing the middle domino (the unsafe act or condition) prevents the injury. From insurance records he concluded that 88 per cent of accidents are caused by unsafe acts, 10 per cent by unsafe conditions and 2 per cent are unpreventable, and that for every major injury there are 29 minor injuries and 300 no-injury accidents (the 1:29:300 ratio). Frank Bird's study of 1969 revised the ratio to 1 serious injury, 10 minor injuries, 30 property-damage accidents and 600 near misses. Accident-proneness theory (Greenwood and Woods, 1919) held that some individuals have more accidents than chance would predict. James Reason's "Swiss cheese" model (1990) sees accidents as the alignment of holes in successive layers of defence — latent organisational failures as well as the active errors of individuals — which shifts attention from blaming the worker to fixing the system.

Accidents are measured by rates that allow comparison between establishments and years. The Indian Standard (IS 3786) uses a base of one million man-hours worked. The frequency rate is the number of lost-time injuries per million man-hours worked: frequency rate = (number of lost-time injuries × 1,000,000) ÷ man-hours worked. The severity rate is the number of man-days lost per million man-hours worked: severity rate = (man-days lost × 1,000,000) ÷ man-hours worked. The incidence rate is the number of injuries per thousand workers employed. A factory that works 6,00,000 man-hours in a year and has 12 lost-time injuries causing 360 man-days lost has a frequency rate of 20 and a severity rate of 600. (American practice under OSHA uses a base of 200,000 hours, which gives smaller numbers for the same experience.)

• Management commitment and a written safety policy: the Factories Act (section 7A) requires the occupier to prepare a written statement of his general policy on the health and safety of workers.
• Safety organisation: safety officers (1,000 or more workers under section 40B), safety committees with equal representation of workers (section 41G for hazardous processes), and supervisors trained in safety.
• Hazard identification and risk assessment, job safety analysis, permit-to-work systems for hot work and confined spaces, safety audits and inspections, and investigation of accidents and near misses.
• Training, safety education, suggestion schemes and safety competitions; the National Safety Council of India (set up in 1966, Mumbai) observes National Safety Day on 4 March, its foundation day.
• National policy and standards: the National Policy on Safety, Health and Environment at Workplace (2009); management-system standards such as ISO 45001 (2018); ILO Conventions 155 and 187, which India has not ratified; and the OSH Code's National Occupational Safety and Health Advisory Board.

An occupational disease is one contracted as a result of exposure to risk factors arising from work. It usually develops slowly, after long exposure, and is often recognised only when it is advanced, which is why periodic medical examination matters. Section 89 of the Factories Act requires medical practitioners and managers to notify the diseases listed in its Third Schedule, and the Employees' Compensation Act (Schedule III) treats the listed occupational diseases contracted in the listed employments as injuries by accident, so that they are compensated. The pneumoconioses — lung diseases caused by inhaling dust — are the most important group in India. Percivall Pott's description in 1775 of scrotal cancer among London chimney sweeps, caused by soot, is usually taken as the first recorded occupational cancer.