Industrial health and safety

Industrial health and safety

An interdisciplinary field that focuses on preventing occupational illnesses and injuries. The disciplines of engineering, epidemiology, toxicology, medicine, psychology, and sociology provide the methods for study and prevention.

Tens of thousands of occupational hazards exist. Occupational hazards can be organized in terms of plants and equipment, the physical work environment, hazards of materials, and task demands. Significant interactions occur between these categories. For example, equipment can modify the work environment by producing noise, potentially hazardous materials, or heat, but will be hazardous only if inappropriate procedures are followed.

Plant hazards are often associated with energy sources and power transmission, processes at the point of operation, vehicles and materials-handling systems, walking and climbing surfaces, ingress-egress, and confined spaces. Hazards in the physical work environment include vibration and noise, thermal extremes, pressure extremes, and ionizing or nonionizing radiation.

Materials used in industrial processes vary greatly in nature and form. Mists, vapors, gases, liquids, dusts, and fumes from certain materials may be hazardous. Some materials pose fire and explosion hazards. Others are chemically or biologically active when they contact or enter the human body. Even chemically inert materials can cause injuries or illness.

The task performed by a worker can be hazardous. Lifting, pushing, pulling, and other physical activity can cause injury when applied or reactive forces, pressures, or torques exceed the tolerance of the body. Repeated performance of manual tasks over prolonged periods, excessive reaches, twisting motions, rapid movements, and postures that concentrate forces can significantly increase the risk of injury. Tasks that are stressful or monotonous can also contribute to human error. Changes in work conditions requiring deviations from ordinary routines, such as when equipment is being repaired, are particularly likely to increase the chance of errors.

A fundamental safety and health activity is to identify potential hazards and then to analyze them in terms of severity and probability. This process allows the cost of control measures to be compared with expected loss reduction and helps justify choices between control alternatives.

Hazard identification is guided by past experience, codes and regulations, checklists, and other sources. This process can be organized by separately considering each step in the making of a product. Numerous complementary hazard analysis methods are available, including failure modes and effects analysis, work safety analysis, human error analysis, and fault tree analysis. Failure mode and effects analysis systematically documents the effects of malfunctions on work sheets that list the components of a system, their potential failure modes, the likelihood and effects of each failure, and potential countermeasures. Work safety analysis and human error analysis are related techniques that organize the analysis around tasks rather than system components. This process involves an initial division of tasks into subtasks. For each subtask, potential effects of product malfunctions and human errors are then documented. Fault tree analysis takes an approach that begins with a potential accident and then works down to its fundamental causes. Fundamental causes may be system malfunctions, human errors, or ordinary nonmalfunction states. Probabilities are often assigned to the fundamental causes, allowing the probability of accidents to be calculated. See Operations research, Risk assessment and management, Systems analysis

Determining which standards, codes, and regulations are relevant and then ensuring compliance are essential health and safety activities. In the United States the best-known governmental standards are the general industry standards specified by the Occupational Safety and Health Administration (OSHA). OSHA also specifies standards for the construction, maritime, and agriculture industries. Other standards include those specified by the Environmental Protection Agency (EPA) on disposal and cleanup of hazardous materials, the Federal Aviation Administration (FAA) standards on worker safety in air travel, the Federal Highway Administration (FHWA) standards regarding commercial motor carriers, the Mine Safety and Health Administration (MSHA) standards for mine workers, the Nuclear Regulatory Commission's and Department of Energy's standards regarding employees working with radioactive materials, and the U.S. Coast Guard standards regarding safety of workers on tank and passenger vessels. State and local governments may also implement safety and health standards.

Methods of controlling or eliminating hazards include plant or process design; job design; employee selection, training, and supervision; personal protective equipment; and warnings. Accident investigations, plant inspections, and environmental monitoring are complementary ways of ensuring that implemented control strategies are fulfilling their intended function. They can uncover deficiencies in existing controls and help formulate needed changes.