Describe the prevention of occupational disease and the promotion of safety at work.

The Hierarchy of Control

• The hierarchy in order, which must be given in order because the order is the content:
• 1. Elimination — remove the hazard or the process entirely. The most effective and usually the least considered
• 2. Substitution — replace the hazardous substance or process with a safer one: toluene for benzene, synthetic abrasives for sandstone, water-based for solvent-based paints, wet drilling for dry
• 3. Engineering controls — enclosure and isolation of the process; local exhaust ventilation at the point of generation; wet methods to suppress dust; general ventilation; machine guarding; and automation
• 4. Administrative controls — rotation of workers to limit exposure duration; reducing the number exposed; safe systems of work and permits; training; housekeeping; and maintenance schedules
• 5. Personal protective equipment (PPE) — respirators, gloves, goggles, hearing protection, aprons and safety footwear
• Why PPE IS last is the point of the whole hierarchy, and should be argued rather than asserted:
• It protects only the individual wearing it, and only while it is worn correctly
• It depends on constant human compliance, at every moment of every shift
• It is frequently uncomfortable, especially in the Indian climate, so it is removed
• It requires correct fit, and a respirator does not seal over a beard
• It requires maintenance, cleaning and replacement of filters
• It may give a false sense of security, so that riskier behaviour is adopted
• And it fails silently — a worn-out filter or a poorly sealed mask gives NO warning that it has stopped working
• By contrast an engineering control protects everyone in the area, all the time, without anyone having to remember anything — which is precisely the same principle as making the healthy choice the easy choice
• PPE is therefore appropriate as a supplement, during maintenance and emergencies, or where higher controls are genuinely not feasible — not as the primary measure, which is how it is most often used
• Local exhaust ventilation deserves particular emphasis, since it captures the contaminant AT the point of generation before it reaches the worker’s breathing zone, and is far more effective and far cheaper to run than diluting it with general ventilation afterwards

Accidents, Safety and the Occupational Health Programme

• Accidents at work cause a very large share of the occupational health burden, particularly in construction, mining, agriculture and small workshops
• The agent factors — unguarded machinery; electrical hazards; falls from height; falling objects; confined spaces; fire and explosion; and manual handling
• The host factors — inexperience, particularly in the first weeks of a job; fatigue and long hours; night and shift work; alcohol; illness and poor vision; and inadequate training
• The environmental factors — poor lighting; noise masking warnings; heat; poor housekeeping and cluttered floors; overcrowding; and production pressure
• The concept of "accident proneness" should be treated critically — it attributes accidents to a defective individual and so diverts attention from the system that permitted the accident
• Modern safety thinking rejects it, holding that a system in which one moment of human inattention causes injury is an unsafe system, whoever is inattentive
• The principle follows — design the system so that the safe way is the easy way and the unsafe way is difficult or impossible, by guarding, interlocks, fail-safe design and forcing functions
• Accident investigation should seek system causes rather than individual blame, because a blame-based investigation produces concealment of near-misses, and near-misses are the free warnings that prevent the next serious injury
• The measures of safety performance — frequency rate (accidents per million man-hours worked); severity rate (days lost per million man-hours); and the incidence rate per 1000 workers
• Near-miss reporting is the most valuable safety activity, since it identifies hazards before anyone is hurt and is only possible in a NO-blame culture
• The elements of a comprehensive occupational health and safety programme:
• A written policy with visible commitment from the top
• Hazard identification and risk assessment for every process
• Control by the hierarchy
• Environmental and biological monitoring
• Medical surveillance — pre-placement and periodic examination
• Training and induction of every new worker before starting
• Emergency preparedness — fire, spill and rescue plans, drills, first aid and antidotes available
• A safety committee with worker representation
• Record keeping, notification and investigation of incidents
• Rehabilitation and return-to-work programmes
• Audit and periodic review
• Worker participation is essential rather than decorative — the workers know where the short-cuts are taken and where the guards are removed, because they are the ones who take and remove them, and no inspection discovers this
• They also have a direct interest in the outcome that no external inspector has
• The role of return to work — prolonged absence itself becomes a barrier to return, so early, graded and modified return with adjusted duties produces better outcomes than waiting for complete recovery
• The economic argument is worth making, since it is what persuades employers — prevention is cheaper than the costs of absence, compensation, replacement and retraining, lost production, damaged equipment, litigation and reputation
• PPE is last because it fails silently; a worn filter gives no warning that it has stopped working
• A respirator will not seal over a beard, which is a fit problem no amount of training solves
• Engineering controls protect everyone all the time without anyone having to remember anything
• Local exhaust captures at the point of generation, which is cheaper and more effective than diluting afterwards
• Treat accident proneness with suspicion, since a system where one lapse causes injury is an unsafe system
• Blame-based investigation hides near-misses, which are the free warnings that prevent the next serious injury
• Design so the safe way is the easy way, through guarding, interlocks and forcing functions
• New workers are injured in the first weeks, which is when induction and supervision matter most
• Worker participation is essential, not decorative, since they know where the guards are removed because they remove them
• Early graded return beats waiting for full recovery, since prolonged absence itself becomes a barrier to returning
• Prevention is cheaper than compensation, absence, retraining, lost production and litigation combined
• Substitution is the most neglected step, and frequently the simplest once someone thinks to ask about it