This resource is provided to help Australian businesses and organisations understand the issues surrounding occuptational hygiene.

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What are Occupational Hygienists?

An occupational hygienist is a qualified, trained and experienced scientist or engineer who can conduct monitoring and provide professional advice on workplace associated hazards. Workplace hazards include:

  • Indoor air quality (air quality associated with offices or accommodation);
  • Industrial air quality (air quality associated with the mining/manufacturering/processing industries);
  • Ambient air quality (air quality associated with the outdoor environment);
  • Asbestos;
  • Noise;
  • Vibration;
  • Thermal extremes; and
  • Odour.

When or why do I need an occupational hygienist?

Each workplace is required to conduct internal risk assessments on each of their processes with regards to work place health and safety requirements. Where the risk assessment identifies hazardous activities with the potential for worker exposure, the process should be monitored initially to determine the level of worker exposure and may require periodical monitoring thereafter depending on the initial outcomes. Alternatively the need to conduct workplace monitoring may be triggered by health concerns raised by employees.

Monitoring can be conducted by site personnel if they are trained in the appropriate sampling methodologies. However it is often better to engage an occupational hygienist. The occupational hygienist will maintain independence from the company were the monitoring is being conducted and will be trained and experienced in the correct sampling requirements. Each of the hazards listed above is a specialist field, therefore it is important to ensure that the occupational hygienist engaged is suitably qualified and experienced in the type of monitoring that you or your company require.

What are some of the common health concerns?

Health effects can range in severity from non-specific illness (such as those associated with sick building syndrome) to loss of concentration and headaches to central nervous system impacts depending on the degree of exposure, route of exposure (skin contact, inhalation etc) and the exposure source (physical, chemical, biological etc). These health impacts can either persist for the exposure duration (known as short-term acute exposure) or can remain in the system long-term (known as chronic exposure) and be life threatening.

Short-term acute exposure can be experienced immediately and reduce or disappear once the person is removed from the hazard exposure with no residual impact. The impact can gradually worsen with repeated exposure (chronic exposure) or may not present until years/decades after the exposure e.g. cancer.

Occupational Monitoring - what's required?

Below is an outline of the steps involved in conducting an effective occupational monitoring program:

  1. Where there have been no reported complaints: Conduct an internal risk assessment of all processes which identifies potential hazards (i.e. develop a list of chemicals that may be a potential health concern or hazard, these can be obtained from the Material Safety Data Sheets for each chemical) or alternatively conduct a workplace audit into the activities being conducted by site personnel and the hazards associated with those processes/activities. In some instances both a review of MSDSs and an onsite audit of activities may be required.
    Where there have been reported adverse health impacts: Discuss with personnel the specific health impacts experienced and conduct an audit of the potential cause (e.g. are the complaints associated with a particular process/activity). Where it is a potential chemical source compile a list of the MSDSs associated with the identified process/activity.
  2. Based on the known hazards/adverse health impacts the monitoring needs to be designed to be inclusive of these hazards and impacts. In the instance of air quality associated with industrial/manufacturering or mining processes a review of the material safety data sheets (MSDS) should identify which chemicals or processes are most likely to cause health concerns. The monitoring must include these parameters. Physical impacts associated with noise and vibration can also adversely impact on the human body and need specific specialised monitoring to determine their impact.
  3. Determine the most appropriate method of monitoring and sample collection (e.g. personal air monitoring or biological monitoring). The methodology should follow either a nationally accepted or internationally accepted standard (e.g. Australian Standard; International Organisation for Standardisation [AS / ISO] or National Institute for Occupational Safety and Health [NIOSH]).
  4. Conduct the hazard monitoring (in the case of air contaminants this will involve the collection of an air sample from within a persons breathing zone while the typical work is being conducted). The monitoring often involves sample collection regardless of the hazard type or monitoring in the case of noise and vibration. An audit of the activities occurring during the hazard monitoring will also be conducted.
  5. Arrange for analysis of the sample/s. This best done by a NATA (National Association of Testing Authorities) accredited laboratory for that specific test.
  6. Interpret the sample results and prepare a report advising on the extent of worker exposure and comparison to guidelines. Where the monitoring/sample results indicate an unacceptable exposure exists recommendations on how to mitigate the problem should also be provided in the report.

Once the report has been provided to the employer, it is the employer's responsibility to implement the recommendations outlined in the report or implement alternative measures to reduce the risk of exposure to their workers. Depending on the occupational hygienist's experience they may be able to provide further assistance with implementing the measures recommended. Where the initial monitoring indicated an unacceptable exposure repeat monitoring is required once control measures have been implemented. The repeat monitoring is to demonstrate that the control measures are effective and that worker exposures have been reduced to safe levels.

What are examples of some of the common control measures to reduce worker exposure?

Control measures can be split into either engineering controls or administrative controls. Engineering controls are usually the most effective method of reducing worker exposure. Engineering controls typically require more initial capital expenditure but where they are well designed and maintained they often have long-term economic benefits by an increase in process efficiency and reduced worker absence. Administrative controls usually require lower capital expenditure, are relatively easy to implement as they often involve a change in the working procedure but they can be compromised by individual worker application. The success of administrative controls is usually dependant on implementing worker training and awareness programs (both short-term and long-term).

Problem Cause Engineering Control Administrative Control
Mould on walls - espiratory complaints Excessive moisture - air has a high relative humidity Reduce relative humidity to 50% through installation of relative humidity controlled air conditioners. Increase outdoor air intake.
Industrial hearing loss / ringing in the ears Excessive noise >85dB(A) Retrofit noise producing equipment with noise attenuation devices. Source equipment fitted with acoustic controls. Worker rotation on job activities where there is noise exposure. Provide PPE (ear plugs or ear muffs) and training on the correct use of PPE,
Heat exhaustion Excessive heat or prolonged exposure Erect shade structures over worksites. Provide water and/or electrolyte replacement stations in convenient locations for workers to access. Provide worker training/awareness on early detection of heat exhaustion symptoms and how to avoid heat exhaustion. Reschedule activities that are prone to heat exposure to avoid midday heat (e.g. 6am-10am and 3pm-7pm). Reduce shift durations.
Non-specific illnesses - usually indicated by an increase in illness frequency of a worker Sick Building Syndrome associated with indoor contaminants such as formaldehyde and Volatile Organic Compounds Increase indoor ventilation to suit building area and number of occupants. Ensure air conditioning systems exchange indoor/outdoor air. Use low formaldehyde and VOC emitting building materials and fittings. Good building design.
Skin and or respiratory irritation/complaints Excessive exposure - can be chemical, biological or physical source Implement chemical containment measures e.g. fully enclosed mechanical loading systems - rather than manual loading systems. Implement PPE to include respirators and long sleeve and trouser protection.
Central nervous system impairment Excessive chemical exposure Appropriate respirators depending on toxicity of chemical