Occupational Hygiene (Exposure/Air Analysis Monitoring and Personal Dosimetry)

The Safety Health and Welfare at Work, Noise Regulations and the Vibration Regulations, Current Edition requires that the University and relevant College/School/Department/Centre/Unit undertake risk assessments where staff or other persons present at a place of work may be exposed to hazardous levels of noise at work and vibration (hand-arm vibration and/or whole-body vibration).

The Safety Health and Welfare at Work (Chemical Agents) Regulations, Current Edition requires that the University and relevant College/School/Department/Centre/Unit undertake risk assessments where staff may be exposed to hazardous substances/chemical agents. To this end a supporting Code of Practice specifies a maximum of 8 hrs and 15-minute exposure limits or maximum exposure limits for a wide range of chemicals which shall not be exceeded. In general, it is best practice to operate to below 33% of a current limit. In the cases of carcinogens there will be no safe exposure limits.

This Code of Practice together with supplier Material Safety Data Sheets, staff scientific knowledge/experience, occupational medical knowledge, staff ill-health records and hazard identification undertaken by dept personnel should indicate substances whose use (or circumstances of use) pose a risk to personnel.

In these cases, the College/School/Department/Centre/Unit will need to directly engage an independent, qualified occupational hygienist to undertake such assessments or air quality analysis (which may or may not involve personal dosimetry), at regular intervals and at least annually in the case of high risk physical and chemical agents. The costs involved are substantial and need to be met from School/Department budgets

In the case of high-risk potential/known occupational hazards that have an accompanying necessity to actively controlled exposures, both regular use and in maintenance/repair (at levels that are not injurious to health in accordance with SHWW Regulation), then a regular/annual occupational hygiene monitoring programme will be required. In such circumstances one off occupational hygiene monitoring will not suffice, nor will infrequently monitoring.

One off monitoring by a competent hygienist may however usefully confirm/verify that no significant risk to health exists at a given point in time or that levels are below levels of detection.

The onus of proof and verification of compliance with exposure standard, limits and regulatory obligations rests with the employer and the senior executive controlling mind in charge of the OH&S risk activity and place of work.

The necessity for expensive occupational hygiene assessments and indeed value of undertaking personal dosimetry and to a lesser extent air analysis at static or fixed points, is related to a proper risk assessment. The following are pertinent to such determinations:

The process involved and the properties of materials/ substance involved. The opportunity to introduce lesser hazard risk substitution or risk avoidance changes in the state / phases of materials used or fumes/ dust/ vapour generated. The quantities involved, frequency and circumstances of use together with the availability and utilisation of fume cupboards, local exhaust ventilation and other containment methods to capture or contain exposure at source (allied to the efficiency of extraction and containment levels - in the case of fume cupboards).

The use by College/School/Department/Centre/Units of Draeger pumps for the instantaneous indication of the presence of a given substance within certain ranges and stain badges may also be of value in conducting preliminary assessment at minimal costs. Use of vane anemometers, Lux meters and variable capacitance accelerometers are also useful for measuring air velocity speeds, lighting levels and vibration acceleration rates respectively.

All results of risk exposure assessments and monitoring should be maintained within the College/School/Department/Centre/Units and copied to the Health and Safety Office. Staff who are exposed to exposure levels which approach or exceed the limits specified in the SHWW Regulations or related Codes of Practice, will need to be referred to the University Occupational Health Physician for Health Surveillance.

In the case of research work involving the creation of new substances or where occupational exposure values have not been otherwise established, then the PI/research team involved must establish its own ‘temporary’ occupational exposure values. This must be undertaken in consultation with a toxicologist and a competent occupational hygienist. The researchers must then work to the highest level of risk control so as, to minimise exposure to the lowest level practicable. E.g., treat as the maximum risk and deploy maximum controls until proven otherwise.