Industrial Hygiene

Introduction 

Industrial hygiene is an art of science devoted to anticipation, recognition evaluation and control of all the factors that arise from the workplace which can cause sickness / illness among the workers.           

Industrial Hygiene:        In the first century AD/ Pling the Elder, Roman scholar came to know the health risks to those working with Zinc and Sulphur. He advised and designed a face mask from animal bladder to protect workers from dust and lead fumes.

          In second century, AD, there were occupational hazardous exposure of copper miners to acid mists. In fourth century, Hippocrates noted that lead’s toxicity in the mining industries. In 1556, German Scholar, Agricola advanced the importance of industrial hygiene and wrote a book. De Re Metallica (Diseases of Miners) which described the diseases of miners and preventive measures. He describes more about Silicosis.

          In 1700, Bernardo Ramzinni (known as the “father of industrial medicine” published first book on industrial medicines – De Morbis Artificum Diatriba. This book is known as Diseases of Workmen. He wrote all about occupational diseases.

          Industrial hygiene received another boost in 1743 when Ulrich Ellenborg published a posture on occupational disease and injuries among gold miners. Ellenborg also wrote about the toxicity of Carbon Monoxide, Mercury, Lead and Nitric Acid.

          Factory Act established in 1948 with its objective “to secure the health, safety and welfare of workers”.

Anticipation:        This involves identifying potential hazards in the workplace before they are introduced.

Recognition:         This involves identifying the potential hazard that a chemical, physical, biological agent or an adverse ergonomic situation poses damage or harm to health.

Evaluation: Evaluation of the extent of exposure to the chemical hazards, physical, biological agents in the workplace.

Eg: Breathing zone, hearing zone.

Control:      Control of the chemical, physical, biological agents or adverse ergonomics situation by procedural engineering or other means where the evaluation indicates that this is necessary.

Hierarchy of Hazard Control

Hierarchy of hazard control is a system used in enormous industries and numerous safety organizations to minimize or eliminate exposure to hazards (Occupational Hazards). This concept is taught to managers in industry, to be promoted as standard practice in the workplace.

    The hierarchy of controls is a core component of prevention of hazards through design, the concept of applying methods to minimize occupational hazards early in the design process.

Elimination

    It means ‘elimination of hazards’ at workplace. Physical removal of the hazard is most effective hazard control. 

For example, 

    if employees must work high above the ground, the hazard can be eliminated by moving the piece they are working on to ground level to eliminate the need to work at heights.

Substitution

Substitution, the second most effective hazard control, involves replacing something that produces a hazard with something that does not produce a hazard or produces a lesser hazard.

Substitution occurs when a new chemical or substance that is less hazardous is used instead of another chemical.

• Benzene instead of Ketones, Toluene.
• Carbon Tetrachloride instead of Dichloromethane.

Engineering Control

The third most effective means of controlling hazards is engineering controls. These do not eliminate occupational hazards, but rather isolate people from hazards.

    Engineering controls are methods that are built into design of a plant, equipment or process to minimize the hazard. Engineering control are a very reliable way to control worker exposure as long as the controls are designed, used and maintained properly. The basic types of Engineering controls are:

• Process Control: Process control involves changing the way a job activity or process is done to reduce the risk.

    Example of process changes include to use wet methods rather than dry when drilling or grinding. Wet method means that water is sprayed over a dusty surface to keep dust levels down or material is mixed with water to prevent dust from being created.

• Enclosure and Isolation: These methods aim to keep the chemical “in” and the worker “out” or vice-versa.
  An enclosure keeps a selected hazard “physical” away from the worker. Enclosed equipment, for example is tightly sealed and it is typically only opened for leaning or maintenance.

• Ventilation: Ventilation is a method of control that strategically “adds” and “removes” air in the work environment. Ventilation can remove or dilute an air contaminant if designed properly. Local exhaust ventilation is very adaptable to almost all chemicals and operations. It removes the contaminant at the source so it cannot disperse into the water space, and it generally uses lower exhaust rather than general ventilation (general ventilation usually exchange air in the entire room).

Administrative Control

      Administrative controls are changes to the way people work. Administrative control limit worker exposure by scheduling shorter work times in contaminant areas or by implementing other rules.

Work practices: Safe Working practices are also a form of administrative controls. In most workplaces, even if there are well designed and well-maintained engineering controls present safe work practices are very important.

• Keeping equipment well maintained.
• Establishing and maintaining good housekeeping programs.

Education and Training: Employee education and training (i.e. Toolbox Talk, etc.) on how to conduct their work safely helps to minimize the risk of exposure and is a critical element of any complete workplace health and safety program.

Good House Keeping: It is essential to prevent the accumulation of hazardous or toxic materials.

 PPEs

    Personal Protective Equipment is the least effective means of controlling hazards because of the high potential for damage to render PPE ineffective.

Examples,

    gloves, safety glasses, hearing protection, helmets, respirators, etc. The employers should implement PPE program in their organizations to prevent accident / injuries by sequence as follows:

• Workplace hazards assessment.
• PPE selection and use.
• Inspection and replacement of damaged or worn-out PPE.
• Employee education & training.
• Program monitoring for continued effectiveness.

    Employers often do not rely on PPEs alone to control occupational hazards when other effective control segments are available. PPEs can be effective, but only when workers use it correctly and consistently. PPE might seem to be less expensive than other controls but can be costly over time.