FAQs: Why do I need an Occupational Hygienist?

With 1.3 million workers in the UK suffering from work-related health issues, the occupational hygienist plays a crucial role in ensuring the health of employees in the workplace.

In 2016/2017, 25.7 million working days were lost due to ill health so preventing or minimising ill health from work-related exposure is both a statutory requirement and a priority for organisations with employees at the forefront.

An occupational hygienist assesses the workplace risk and evaluates the likelihood of exposure to chemical, physical and biological hazards.

Information gathered from exposure monitoring and assessment can be used to implement prevention and control measures in eliminating or reducing exposure to these hazards.

An occupational hygienist offers the client advice and guidance in

establishing a monitoring regime
understanding the legal requirements and importance of risk reduction
applying the principles of good practice for the control of exposure to substances hazardous to health (as per COSHH schedule 2A)
undertaking on-site assessments to identify the level of personal exposure and the control measures required which are proportionate to that risk.

The employer is legally required to ensure the health and safety of their employees. Depending on the specific area of concern, the HSE regulations outline this requirement.

Should the risk assessment deem it necessary, the employer must carry out exposure monitoring for their employees and undertake an evaluation into the performance of the control measures in place.

The employer must appoint a person to carry out the required monitoring and assessments and the employer must ensure that this person is competent to do so.

The employer can obtain this service from a competent occupational health professional such as an occupational hygienist. 

Workplace risks can include exposure to chemical, biological, physical, psychological or ergonomic hazards.  Examples of some common exposure risks include:

Airborne hazardous substances

If the risk assessment indicates that monitoring is required to assess exposure, COSHH regulation 10 ‘Monitoring exposure at the workplace’ requires that suitable procedures and techniques are employed.

To monitor exposure to most airborne hazardous substances, selected employees are required to wear a light-weight sampling kit for a proportion of their working day. From this, laboratory results are analysed and compared against workplace exposure limits (WELs), as set out in HSE document EH40. The results – as well as a summary of on-site observations – make up a comprehensive report which can provide valuable information on the effectiveness of control measures and recommendations for improvement.

One such control measure can include a Local Exhaust Ventilation (LEV) system which helps in minimising employee exposure to airborne contaminants.


As part of COSHH regulation 9 ‘Maintenance, examination and testing of control measures’, LEV systems require thorough examination and testing at least once every 14 months.

The occupational hygienist observes the actual use of the LEV system and its ability to adequately control exposure to hazardous substances by testing the air flow at the contaminant source, extraction hood opening and within the ductwork.

Recommendations can then be given as required to include improvement of working practices, system redesign, conditions of effective use, and a plan for continued adequate performance via routine checks, maintenance and repair work. Guidance is taken from HSE document HSG 258 in carrying out LEV assessments.
 

Exposure to occupational noise

Monitoring exposure to occupational noise falls under The Control of Noise at Work Regulation 2005 ‘Assessment of the risk to health and safety created by exposure to noise at the workplace’.

Typically, a selection of employees in roles of potential exposure are equipped with dosebadges (personal noise measurement devices) which record noise levels within their vicinity for a representative period of their work shift. These results are compared against the exposure action values and exposure limit value (as Lepd).


By walking through the site, the occupational hygienist can identify and measure sources of elevated noise. Personal noise exposure levels and background noise measurements are included in a report, alongside a noise map of the workplace. Hearing protection (HP) is observed and assessed determine the suitability. If the hearing protection is found to be unfit for purpose, alternatives are recommended.

Emphasis is given, however, on noise exposure prevention and noise control measures through technical and organisational means; personal hearing protection should be used only where there is a need to provide additional protection beyond these control measures. An occupational hygienist can advise accordingly on the most suitable means of noise exposure reduction.


Exposure to vibration
The Control of Vibration at Work regulation 5 states there must be an ‘assessment of the risk to health created by vibration at the workplace’.


There are two types of vibration exposure that must be considered:

Hand arm vibration (HAV)
To protect workers from vibration risks, tools identified as a HAV risk on-site are selected for monitoring.
Using a Human Vibration Meter – a piece of equipment designed for, quite literally, measuring human vibration in the workplace – the employee carries out the normal work process until a result is obtained, typically after a few minutes. The data is interpreted and evaluated, taking into account frequency weighting and how the tool is used; for example, whether the right/left hand is used and the type of material the tool is applied to.
Exposure is evaluated based on the vibration magnitude and the typical length of time the tool is used for.

Whole body vibration (WBV)
Similar to HAV, WBV is measured using the Human Vibration Meter with a Seat Pad Accelerometer. Mobile plants that are identified as a WBV risk are monitored during a period of normal operation. Exposure to WBV takes into account frequency weighting, affecting factors (such as seat type, tyre type, road conditions), vibration magnitude as well as typical length that mobile plant is being used.

For both HAV and WBV, the results are compared against the exposure action value and exposure limit value (as A(8)). An occupational hygienist can provide site specific and generic recommendations in vibration exposure reduction are given. Due to variation of both daily tool and mobile plant use, the client is given the information needed to keep track of and calculate daily exposure of their workers.

There are a number of regulation and guidance documents which outline when workplace monitoring is required:

The Control of Substances Hazardous to Health Regulations 2002 (as amended)
The Control of Noise at Work Regulations 2005
The Control of Vibration at Work Regulations 2005
The Control of Lead at Work Regulations 2002
The Control of Asbestos Regulations 2012
The HSE’s health and safety guidance publications are available such as:

HSG 38 ‘Lighting at Work’
HSG 258 ‘Control of Airborne Contaminants at Work’
HSG 187 ‘Control of Diesel Engine Exhaust Emissions in the Workplace’
HSG 53 ‘Respiratory Protective Equipment at Work’