MODULE 7:OCCUPATIONAL HYGIENE

Introduction:
Occupational hygiene is about recognizing, evaluating and controlling physical and chemical hazard in the workplace that arises in a diverse range of work environment. With a full range of industrial hygiene and asbestos related services. Under the Occupational Safety and Health (Use and Standard of Exposure of Chemicals Hazardous to Health) Regulations 2000, where an assessment of risk to health indicates that monitoring of exposure is required or it is requisite for ensuring the maintenance of adequate control of the exposure of employees to chemicals hazardous to health, the employers shall ensure that the exposures of chemicals hazardous to health is monitored in accordance with an approved method of monitoring and analysis.
Occupational hygiene is the discipline of anticipating, recognizing, evaluating and controlling health hazards in the working environment with the objective of protecting worker health and well-being and safeguarding the community at large. Occupational hygiene is considered a "science"; but it is also an art that involves judgment, creativity and human interaction. The field of Occupational Hygiene today has also expanded to included Environment, Health and Safety. Occupational hygiene has a long history and a bright future as a potential career.
Sampling principles
Air sampling is the process of quantifying or determining the identity of a contaminant by the use of standard sampling instruments, techniques and strategy. A sampling device is used to separate and collect the offending material from a measured volume of the atmosphere. The separate material is quantified either instantaneously (if instrument is direct reading) or at a later stage (if instrument is not direct reading). The contaminant levels in the atmosphere are then established in terms of mass or number concentration for particulate, or volume concentration for gases and vapors. A sampling device used to separate and collect the offending material from a measured volume of the atmosphere. The separate material may be quantified:
I. Almost instantaneously (if instrument is direct-reading); and
II. At a later stage (if instrument is not direct reading).
Main Reason for Performing Air Sampling At Workplace:
The objective of sampling strategy is to reduce the variation in the sampling results so that a reliable estimate can be made of the time weighted average exposure concentration.
Work environment sampling is conducted for basally two reasons:
a) To monitor the integrity and performance of hazard control systems
I. Concerned with measuring changes in ambient levels in order to follow trends of improvement or deterioration in air quality.
II. Located in fixed positions and normally in close proximity to contaminant sources.
b) To access health risk of persons at work place
I. Directed towards the measurement of personal exposure to airborne toxic substances.
II. Located on breathing zone and preferably positioned on the person to be assessed.
Monitor Concentration:
I. During normal exposure
II. Before and after control are implemented
III. In cleanup operations (Asbestos)
IV. Confine space entry
V. For regulations reason
Sampling Particulates:
I. Filters
II. Commonly used (25% of sampling methods)
III. Type depends on the contaminant and the method
IV. Thin filters placed in rigid holders (cassettes) with a support pad beneath
V. Open Face Sampling
VI. Top portion of cassette is removed
VII. When distribution across media is important (asbestos)
VIII. Closed Face Sampling
IX. Small plug in top cassette is removed for sampling
X. As in metal sampling
Potential Problems Associated with Filter Collection:
If we used a filter collection, these are the problems or limitation associated with the use of an air sample to represent workers exposure:
I. Overloading
II. Too much particulate collection can overload the filter and cause an error
III. Static Electricity
IV. Filters pick up a charge and can cause an error in gravimetric analysis
V. Moisture or physical damage
VI. After getting wet, filters can tear or burst
VII. Contamination with interfering substances
VIII. Contaminant material causes error in determination of desired material
Limitations of the Adsorbent Tube and Filter Sampling Method:
Filter Sampling Methods Adsorbent tubes and filters are extremely reliable for collecting airborne contaminants, but please note the following limitations:
I. Air sampling devices have unique capacities for each analyze sampled. When this capacity is exceeded, analyze breakthrough occurs. Air sampling recommendations must be followed.
II. An analyze of interest can be displaced by another analyze more strongly adsorbed by the adsorbent.
III. High humidity can severely reduce the breakthrough volumes of adsorbents like charcoal and silica gel. Other adsorbents, such as Carboxen and Supelpak 20 adsorbents, usually are unaffected by moisture.
IV. The desorbing solvent recommended in a specific procedure may not always displace the analyze from the adsorbent. If necessary, choose a more effective solvent.
V. Reactive analyses can be converted to other species during the collection process, hence quantization may be inaccurate.
Conclusion:
The protection of workers’ health against the hazards due to the contamination of air at the workplace and the prevention of contamination of the working environment should be the concern of all those involved in the design, organization and performance of the work and all those concerned with the protection of workers’ health. The principles laid down in this code of practice, which was adopted at a meeting of experts convened by the ILO with the participation of WHO, are intended to stimulate and guide governments, employers and workers, and are to be considered as objectives which may be attained in successive stages in different countries and enterprises according to local circumstances and possibilities. The wording of the code is sufficiently flexible to permit its adaptation in the light of technological progress.

What is Occupational Hygiene?
Occupational hygiene is the discipline of anticipating, recognizing, evaluating and controlling health hazards in the working environment with the objective of protecting worker health and well-being and safeguarding the community at large. Occupational hygiene is considered a "science"; but it is also an art that involves judgment, creativity and human interaction.
The field of Occupational Hygiene today has also expanded to included Environment, Health and Safety.Occupational hygiene has a long history and a bright future as a potential career.

What is an Occupational Hygienist?
Occupational hygienists are scientists and engineers committed to protecting the health and safety of people in the workplace and the community. Traditionally occupational hygienists worked primarily in factories and other industrial settings but as our society has changed, so has the definition of occupational hygiene. Today, Occupational hygienists can be found in almost every type of work setting

What is the difference between Industrial and Occupational Hygiene?
There is no difference. The term Industrial Hygiene originated in the USA while in other parts of the world the discipline is known as Occupational Hygiene. In some ways, Occupational is a better descriptor because health risks occur in all places that people work, including offices, shops, banks, hospitals and farms, not just in those workplaces that one thinks of as industrial.

What does an Occupational Hygienist do?
The goal of the occupational hygienist is to keep workers, their families, and the community healthy and safe. They play a vital part in ensuring that federal, provincial/territorial, and local laws and regulations are followed in the work environment
Occupational Hygienists may be found working to prevent ergonomic injuries in the office; measuring noise levels at an airport; supervising the safe removal of lead, mold or asbestos; and in thousands of other settings. Occupational
hygienists may sample air, soil or water to determine if there are harmful substances present. They may fit test a respirator to ensure that a worker is breathing cleaner air.
Typical roles of the occupational hygienist include:
• Investigating and examining the workplace for hazards and potential dangers
• Making recommendations on improving the safety of workers and the surrounding community
• Conducting scientific research to provide data on possible harmful conditions in the workplace
• Developing techniques to anticipate and control potentially dangerous situations in the workplace and the community
• Training and educating the community about job-related risks
• Advising government officials and participating in the development of regulations to ensure the health and safety of workers and their families
• Ensuring that workers are properly following health and safety procedures