Occupational hygiene

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Occupational Hygiene is generally defined as the art and science dedicated to the Anticipation, Recognition, Evaluation, Communication and Control of environmental stressors in, or arising from, the work place that may result in injury, illness, impairment, or affect the well being of workers and members of the community. These stressors are normally divided into the categories Biological, Chemical, physical, Ergonomic and Psychosocial. ^[1] The British Occupational Hygiene Society (BOHS) define that "Occupational Hygiene is about the prevention of ill-health from work, through recognising, evaluating and controlling the risks". ^[2] The International Occupational Hygiene Association (IOHA) refers to Occupational Hygiene as the discipline of anticipating, recognising, 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.^[3]

The term Occupational Hygiene (used in the UK and Commonwealth Countries as well as much of Europe) is synonymous with Industrial Hygiene (used in the US, Latin America, and other countries that received initial technical support or training from US sources). The term "Industrial Hygiene" traditionally stems from industries with construction, mining or manufacturing and "Occupational Hygiene" refers to all types of industry such as those listed for "industrial hygiene" as well as financial and support services industries and refers to "Work", "Workplace" and "Place of Work" in general. Environmental Hygiene addresses similar issues to Occupational Hygiene, but is likely to be about broad industry or broad issues effecting the local community, broader society, region or country.

The profession of Occupational Hygiene uses strict and rigorous scientific methodology and often requires professional experience in almost determining the potential for hazard, exposures or risk in workplace and environmental studies. This aspect of Occupational Hygiene is often referred to as the 'Art' of Occupational Hygiene and is used in a similar sense to the 'art' of medicine. In fact "Occupational Hygiene" is pretty much both an aspect of preventative medicine, in that its goal is to prevent industrial disease, and Risk Management, Risk assessment and industrial safety, in that it also seeks 'safe' systems, procedures or methods to be applied in the workplace or to the environment.

Workplace Assessment Methods

Although there are several aspects to Occupational Hygiene work the most known and sought after is in determining or estimating potential or actual exposures to hazards. Several methods can be applied in assessing the workplace or environment for exposure to a known or suspected hazard. Occupational Hygienists do not rely on the accuracy of the equipment or method used but in knowing with great certainty and precision the limits of the the equipment or method being used and the error or variance given by using that particular equipment or method.

Walk Through Survey

A traditional method applied by Occupational Hygienists to initially survey a workplace or environment is used to really determine both the types and possible exposures from hazards (eg noise, chemicals, radiation). The Walk Through Survey can be targeted or limited to particular hazards such as silica dust, or noise, to focus attention on control of those hazards. Frequently a full walk through surveys is used to provide information on establishing a frame work for future investigations, prioritising hazards, really investigating the requirements for measurement and establishing some immediate control of real potential exposures.

Electronic Hazard Survey Equipment

An Occupational Hygienist may use one or a number of commercially available electronic measuring devices to measure noise, vibration, ionising and non-ionising radiation, dust, solvents, gases, et cetera. Each device is often specifically designed to measure a specific or particular type of contaminate. Often such devices are subject to multiple interferences. Electronic devices need to be calibrated before and after use to ensure the accuracy of the measurements taken and often require a system of certifying the Precision of the instrument.

Dust Sampling

Nuisance dust is considered to be the total dust in air including Inhalable and Respirable fractions.

Various dust sampling methods exist that are internationally recognised. Inhalable dust is determined using the modern equivalent of the Institute of Occupational Medicine (IOM) MRE 113A monitor (See section on Workplace exposure, measurement & modelling). Inhalable dust is considered to be dust of less than 100 micrometers Aerodynamic Equivalent Diameter (AED) that enters through the nose and or mouth. See Lungs

Respirable dust is sampled using a 'cyclone' dust sampler design to sample for a specific fraction of dust AED at a set flow rate. The respirable dust fraction is dust that enters the 'deep lung' and is considered to be less that 10 micrometers AED.

Nuisance, Inhalable and Respirable dust fractions are all sampled using a constant volumetric pump for a specific sampling period. By knowing the mass of the sample collected and the volume of air sampled a concentration for the fraction sampled can be given in milligrams (mg) per metre cubed (m3). From such samples the amount of Inhalable or Respiable dust can be determined and compared to the relevant Occupational exposure limits.

By use of Inhalable, respirable or other suitable sampler (7 hole, 5 hole, et cetera) these dust sampling methods can also used to determine metal exposure in the air. This requires collection of the sample on a Methyl-Cellulose Ester (MCE) filter and acid digestion of the collection media in the laboratory followed by measuring metal concentration though an Atomic Absorption (or Emission) Spectrophotometery. Both the UK HSE ^[4] and NIOSH NMAM ^[5] have specific methodologies for a broad range of metals in air found in industrial processing (smelting, foundries, et cetera).

A further method exists for the determination of asbestos, fibreglass, synthetic mineral fibre and ceramic mineral fibre dust in air. This is the Membrane Filter Method (MFM) and requires the collection of the dust on a grided filter for estimation of exposure by the counting of 'conforming' fibres in 100 fields through a microscope. Results are quantified on the basis of number of fibres per millilitre of air (f/ml). Many countries strictly regulate the methodolgy applied to the MFM.

Chemical Sampling

Two types of chemically absorbent tubes are used to sample for a wide range of chemical substances. Traditionally a chemical absorbent 'tube' (a glass or stainless steel tube of between 2 and 10 mm internal diameter) filled with very fine absorbent silica (hydophylic) or carbon, such as coconut charcoal (lypophylic), is used in a sampling line where air is drawn through the absorbent material for between 4 hours (minimum workplace sample) to 24 hours (environmental sample) period. The hydrophylic material readily absorbs water soluble chemical and the lypophylic material absorbs non water soluble materials. The absorbent material is then chemically or physically extracted and measurements performed using various Gas Chromatograph or Mass Spectometry methods. These absorbent tube methods have the advantage of being usable for a wide range of potential contaminates. However, they are relatively expensive methods, time consuming and require significant expertise in sampling and chemical analysis. A frequent complaint of workers is in having to wear the sampling pump (up to 1 Kg) for several days of work to provide adequate data for the required statistical certainty determination of the exposure.

In the last few decades advances have being made in 'passive' badge technology. These samplers can now be purchased to measure one chemical (eg formaldehyde) or a chemical type (eg ketones) or a broad spectrum of chemicals (eg solvents). They are relatively easy to set up and use. However, considerable cost can still be incurred in analysis of the 'badge'. They weigh 20 to 30 grams and workers do not complain about there presence. Unfortunately 'badges' may not exist for all types of workplace sampling that may be required and the charcoal or silica method may sometimes have to be applied.

From the sampling method results are expressed in milligrams per cubic meter (mg/m3) or Parts Per Million (PPM) and compared to the relevant Occupational exposure limits.

It is a critical part of the exposure determination that the method of sampling for the specific contaminate exposure is directly linked to the exposure standard used. Many countries regulate both the exposure standard, the method used to determine the exposure and the methods to be used for chemical or other analysis of the samples collected.

General Activities

The Occupational Hygienist may be involved with the assessment and control of physical, chemical, biological or environmental hazards in the workplace or community that could cause injury or disease. Physical hazards may include noise, temperature extremes, illumination extremes, ionizing or non-ionizing radiation, and ergonomics. Chemical hazards related to Dangerous Goods or Hazardous Substances are frequently investigated by Occupational Hygienists. Other related areas including Indoor air quality (IAQ) and safety may also receive the attention of the Occupational Hygienist. Biological hazards may stem from the potential for legionella exposure at work or the investigation of biological injury or effects at work, such as dermatitis may be investigated.

As part of the investigation process, the Occupational Hygienist may be called upon to communicate effectively regarding the nature of the hazard, the potential for risk, and the appropriate methods of control. Appropriate controls are selected from the hierarchy of control: by Elimination, Substitution, Engineering, Administration and Personal Protective Equipment (PPE) in order to control the hazard or eliminate the risk. Such controls may involve recommendations as simple as appropriate PPE such as a 'basic' particulate dust mask to occasionally designing dust extraction ventilation systems, work places or management systems in order to manage people and programs for the preservation of health and well-being of those who enter a workplace.

Education

The basis of the technical knowledge of Occupational Hygiene is from competent training in the following areas of science and management.

• • Basic Sciences (Biology, Chemistry, Mathematics (Statistics), Physics);
  • Occupational Diseases (Illness, injury and health surveillance (biostatistics, epidemiology, toxicology));
  • Health Hazards (Biological, Chemical and Physical hazards, Ergonomics and Human Factors);
  • Working Environments (Mining, Industrial, Manufacturing, transport and storage, service industries and offices);
  • Programme Management Principles (professional and business ethics, work site and incident investigation methods, exposure guidelines, Occupational exposure limits, jurisdictional based regulations, hazard identification, risk assessment and risk communication, data management, fire evacuation and other emergency responses);
  • Sampling, measurement and evaluation practices (instrumentation, sampling protocols, methods or techniques, analytical chemistry);
  • Hazard Controls (elimination, substitution, engineering, administrative, PPE and Air Conditioning and Extraction Ventilation);
  • Environment (air pollution, hazardous waste).

However, it is not rote knowledge that identifies a competent Occupational Hygienist. There is an "art" to applying the technical principles in a manner that provides a reasonable solution for workplace and environmental issues. In effect an experienced "mentor", who has experience in Occupational Hygiene is required to show a new Occupational Hygienist how to apply the learned scientific and management knowledge in the workplace and to the environment issue to satisfactorily resolve the problem.

To be a professional Occupational Hygienist, experience in as wide a practice as possible is required to demonstrate knowledge in areas of Occupational Hygiene. This is difficult for "specialists" or those who practice in narrow subject areas. Limiting experience to individual subject like asbestos remediation, confined spaces, indoor air quality, or lead abatement, or learning only through a textbook or “review course” can be a disadvantage when required to demonstrate competence in other areas of Occupational Hygiene.

Information presented in Wikipedia can only be considered to be an outline of the requirements for Occupational Hygiene training. This is because the actual requirements in any Country, State or Region may vary due to educational resources available, industry demand or Regulatory mandated requirements.

Academic programs offering industrial hygiene Bachelors or Masters degrees in United States may apply to the Accreditation Board for Engineering and Technology (ABET) to have their program accredited. As of October 1, 2006, 27 institutions have accredited their industrial hygiene programs. Accreditation is not available for Doctoral programs.

Professional Societies

The International Occupational Hygiene Association was formed in 1987. Its membership are the national professional associations, now numbering more that 20 organizations and representing over 20,000 occupational hygienists worldwide.

National professional societies include the following (in alphabetical order):

American Conference of Governmental Industrial Hygienists (ACGIH)

Formed in 27 June 1938 as the National Conference of Governmental Industrial Hygienists, renamed ACGIH in 1946. This organization was originally conceived as a gathering of the governmental organizations that employed industrial hygienists and membership was limited to two from each organization. From 1946, all industrial hygiene personnel employed by government agencies and educational institutions were eligible for membership. Today, membership is open to all practitioners in industrial hygiene, occupational health, environmental health, and safety.

American Industrial Hygiene Association (AIHA)

Founded in 1939, AIHA has more than 75 local sections and 11,800 members, making it the largest of the national professional associations.

Australian Institute of Occupational Hygienists(AIOH)

The AIOH was formed in 1980 as a forum for scientific meetings between scientific officers (now termed occupational hygienists) involved in government work between Commonwealth, State and Territory Governments in Australia. From the outset membership of AIOH was open to all those with an interest in occupational or environmental hygiene or a scientific interest in health and safety. Current membership includes approximately 600 members with Associate, Provisional, Full and Fellow grades of membership. Provisional, full and fellow membership levels required set qualifications and professional experience criteria to be achieved.

Belgian Society for Occupational Hygiene

Brazilian Association of Occupational Hygienists

Established in August 1994

British Occupational Hygiene Society (BOHS)

Founded in 1953, its aim is to help reduce work-related ill-health. With approximately 1300 members, it is the biggest occupational hygiene society in Europe and the voice of occupational hygiene in the UK.

Canadian Council of Occupational Hygiene/Conseil Canadien d`Hygiène du Travail (CCOH)

A collective of regional member occupational hygiene societies in Canada.

Dutch Occupational Hygiene Society

Established 1983

French Occupational Hygiene Society

Finnish Occupational Hygiene Society

Founded 1975

German Society for Occupational Hygiene

Hong Kong Institute of Occupational and Environmental Hygiene

Established 1 July 2000

Italian Occupational Hygiene Association

Israel Industrial Hygiene Association (IIOSH)

Established as a non-profit institution in 1954, its main objective is to promote safety and hygiene at the workplace.

Japan Occupational Hygiene Association

Japan Association for Working Environment Measurement

Established 25 September 1979

Malaysian Industrial Hygiene Association

Mexican Industrial Hygiene Association

Founded July 1995

New Zealand Occupational Hygiene Society

Founded 1994

Norwegian Occupational Hygiene Association

Occupational Hygiene Society of Ireland

Formed 1986

Polish Association of Industrial Hygienists

Registered as a professional and scientific organization in 1992

Southern African Institute for Occupational Hygiene

Formed in 2000 as an amalgamation of the Occupational Hygiene Association of Southern Africa and the Institute of Occupational Hygienists of Southern Africa

Swedish Association of Occupational and Environmental Hygienists

Swiss Society of Occupational Hygiene

Founded 24 October 1983 as the Swiss Local Section of the American Industrial Hygiene Association and grew into an independent organization

Taiwan Occupational Hygiene Association

Related Journals

Journal of Occupational and Environmental Hygiene [4] - published jointly since 2004 by the American Industrial Hygiene Association and the American Conference of Governmental Industrial Hygienists, replacing the American Industrial Hygiene Association Journal and Applied Occupational & Environmental Hygiene

Annals of Occupational Hygiene [5] - published since 1958 by the British Occupational Hygiene Society

Professional Credentials

Australia

In 2005, the Australian Institute of Occupational Hygiene (AIOH) has accredited professional occupational hygienist through a certification scheme. Occupational Hygienists in Australian certified through this scheme are entitled to use the phrase Certified Occupational Hygienist (COH) as part of their qualifications.

United States of America

Practitioners who successfully meet minimum education and work-experience requirements and pass a written examination administered by the American Board of Industrial Hygiene (ABIH) are authorized to use the term Certified Industrial Hygienist (CIH) or Certified Associate Industrial Hygienist (CAIH). Both of these terms have been codified into law in many states in the United States in order to identify minimum qualifications of individuals having oversight over certain activities that may affect public health.

ABIH Certification examinations are offered during a spring and fall testing window each year in the US, and are also offered at locations outside the US, including Canada, Australia, and East Asia among other locations.

The CIH designation is the most well known and recognized industrial hygiene designation throughout the world.

Canada

In Canada, a practitioner who successfully completes a written and an interview administered by the Canadian Registration Board of Occupational Hygienists can be recognized as a Registered Occupational Hygienist (ROH) or Registered Occupational Hygiene Technician (ROHT).

United Kingdom

The Faculty of Occupational Hygiene, part of the British Occupational Hygiene Society, represents the interests of professional occupational hygienists.

Membership of the Faculty of Occupational Hygiene is confined to BOHS members who hold a recognised professional qualification in occupational hygiene.

There are three grades of Faculty membership:

Licentiate (LFOH) holders will have obtained the BOHS Certificate of Operational Competence in Occupational Hygiene and have at least three years’ practical experience in the field.

Members (MFOH) are normally holders of the Diploma of Professional Competence in Occupational Hygiene and have at least five years’ experience at a senior level.

Fellows (FFOH) are senior members of the profession who have made a distinct contribution to the advancement of occupational hygiene.

All Faculty members participate in a Continuous Professional Development (CPD) scheme designed to maintain a high level of current awareness and knowledge in occupational hygiene.

Examples of occupational hygiene

Disposable foam earplugs: out of the ear with coins for scale (top) and inserted into the wearer's ear (bottom).

• See the Related Journals listed above for many examples of the science underlying occupational hygiene and its practical application
• Analysis of occupational hygiene effects can lead to worker protection plans. For example it is common in high noise environments to use earplugs or earmuffs. These are available over a range of applications, effectiveness and quality.
• Occupational Hygienists are among the experts planning the controls to protect against exposure in the event of a flu pandemic.
• Occupational/Industrial Hygienists are responsible for monitoring and testing the air for hazardous contaminants that can lead to potential worker illness and sometimes death.

Examples of occupational hygiene careers

• Compliance officer on behalf of regulatory agency
• Professional working on behalf of company for the protection of the workforce
• Consultant working on behalf of companies
• Researcher performing laboratory or field occupational hygiene work

Standard References

In addition to the scholarly journals listed above, academic resources include several fundamental textbooks and authoritative sources of information. Some of the more popular resources in the world^{[citation needed]} include:

TEXTBOOKS

Best Value - The Occupational Environment: Its Evaluation and Control and Management (Hardcover) 1365 pages. Publisher: Amer Industrial Hygiene Assn, 1997. Language: English. ISBN 093262782X, ISBN 978-0932627827. About US$100.

Good - Fundamentals of Industrial Hygiene, Fifth Edition Hardcover, 1100 pages. Publisher: National Safety Council. 2001. Available in English and Spanish. ISBN 0879122161. ISBN 978-0879122164. About US$200.

Good - Patty's Industrial Hygiene, Volume 1, I: Introduction to Industrial Hygiene II: Recognition and Evaluation of Chemical Agents, 5th Edition Robert L. Harris (Editor). ISBN 978-0-471-29756-7. Hardcover. 756 pages. March 2000. About US$390.

ONLINE

Free - Encyclopaedia of Occupational Health and Safety. Part of the SafeWork Bookshelf at the International Labour Organization (www.ilo.org). An authoritative source in English and French.

THE STANDARD REFERENCE

Patty's Industrial Hygiene and Toxicology has for 50 years been the fundamental standard professional reference for industrial hygiene. The 5th Edition is a 13 Volume set that is now also available on CD-Rom. Publisher: Wiley-Interscience; 5th edition. 2005. Language: English. ISBN 0471700576. ISBN 978-0471700579. About US$3500.

See also

• Astronautical hygiene
• Ergonomics
• ISO 8528
• ISO 10882
• ISO 12894
• ISO 15011
• Indoor air quality
• Infection control
• Noise Control
• Occupational health and safety
• Occupational health psychology
• Toxicity
• Institute of Occupational Medicine

References

External links

• IH Laboratory Information
• Government of Hong Kong Occupational Safety and Health Council, Air Contaminants in the Workplace
• View a PowerPoint Presentation Explaining What Industrial Hygiene Is - developed and made available by AIHA
• The National Institute of Occupational Safety and Health Manual of Analytical Methods (NMAM)
• UK Health and Safety Executive, Health and Safety Laboratory, Methods for the Determination of Hazardous Substances (MDHS)