Pulsar Instruments plc
For noise meters, sound level meters and industrial noise monitoring
Pulsar Instruments plc are a Made in Yorkshire Silver Member
Why do we all need to be controlling workplace noise? According to the HSE, over one million employees in Great Britain are exposed to levels of noise which put their hearing at risk.
Noise induced hearing loss is one of the most prevalent, but often ignored, risks in the workplace and employees must, by law, be protected. Once noise induced hearing loss has taken place it is irreversible. Clearly prevention is the most sensible option here as 1 in 7 of the UK population are either deaf or hard of hearing.
The increasing ‘claim culture’ dictates that companies must comply with their legal duties as detailed in the ‘Control of Noise at Work Regulations 2005’. These regulations reduced the previous action levels and also introduced ‘Legal Limits’ for daily noise exposure. These changes were driven by a European Directive in a long term attempt to eliminate noise induced hearing loss in the workplace.
This article provides a 5-Step process for companies who are making efforts concerning controlling workplace noise.
Firstly, you need to establish whether there are any noise hazards within your workplace. This can be achieved through a combination of your knowledge of work practices, making straightforward observations and taking some simple noise measurements in areas you suspect may present a risk. Even at this stage you should use an Acoustic Calibrator to calibrate your sound level meter before and after each measurement session and record your measurements.
Having found out which areas may be a noise hazard, you need to identify all employees who could be at risk. Evaluate how harm may occur, for instance damage to
hearing, deafness, tinnitus, impaired communication and inability to hear audible alarms. Also, take into consideration susceptible employees or those that already have an existing hearing condition.
Workplace noise assessment
Talk with the employees to find out their typical work routine. A more detailed series of individual noise measurements is required to determine the
typical exposures of those at risk. You then have a choice of measurement methods.
Integrating Averaging Sound Level Meter
The person carrying out measurements for controlling workplace noise should have sufficient skills to be competent for the task and use a suitable sound level meter. Ideally, it should be compliant to BS EN 61672-1:2003 Class 1 or Class 2 and from a reputable manufacturer. Representative ‘A’ weighted average noise level readings (correctly written as LAeq) are taken for each ‘task’ undertaken by an employee and then, using either software, mathematical formulae or the HSE exposure calculator spreadsheet (available from www.hse.gov.uk/noise/calculator.htm), determine an individual’s exposure level.
In Figure 1 below, all of the exposures have a value of 80dB(A) but the duration of the respective ‘tasks’ has varied greatly. The 80dB(A) exposure equates to an exposure that just puts the worker into the Lower Action Level category.
Figure 1 – Noise levels and their exposure levels relative to time.
The ‘A’ frequency filter is applied by sound measurement instruments in an attempt to replicate the response of the human ear to noise so that we can accurately determine the level of risk rather than the actual true noise level itself.
Personal Noise Dosemeter
Alternatively a dosemeter, like the Pulsar noise doseBadge can be worn by a worker during their entire shift. The doseBadge is worn on the shoulder of the person being monitored and measures the noise levels they receive throughout their working day.
This methodology is particularly effective for workers with unpredictable shift patterns, those constantly on the move, or people working in confined or difficult to access areas (vehicle cabins, emergency services, construction workers, mining industry, maintenance staff etc). Often forgotten is the necessity to assess the risk from any impulsive noise (sudden very loud bangs and crashes) which is done by making a ‘C’ weighted Peak measurement (LCpeak). Most modern sound level meters and dosemeters will measure both the LAeq and LCpeak simultaneously.
Pulsar Noise DoseBadge – wearable noise measurement technology
Having made and evaluated your measurements, a Noise Control Action Plan is required. This plan is the most important part of the whole survey process and should demonstrate that you are taking the necessary steps to control the identified risks. Once an action level has been reached, a corresponding set of actions need to be implemented. Refer to the publication ‘Controlling noise at work’ by the HSE for full information or contact Pulsar Instruments plc directly for a summary sheet.
The action levels for impulsive noise are 135dB(C) and 137dB(C) respectively with the legal limit being 140dB(C). Your plan should include a list of prioritised actions to solve immediate risks and to give consideration to your general duty to reduce noise levels in the workplace. Where noise can’t be reduced at source, suitable hearing protection is required which must be made available to all workers at risk.
Figure 2 – Current levels and limits of an 8 hour period
Arrangements must be made to provide information, instruction and training to both management and workforce with respect to the risks and how to minimise and control them. For any levels where exposures of 85dB or above are Likely, a programme of health surveillance must be introduced to monitor the hearing condition of the employees involved.
All the above findings should be used to create a clear report which should be in a style and format that could be easily referenced in the future. This will provide permanent evidence of the decisions you have taken to comply with the law.
The effectiveness of your programme for controlling workplace noise should be regularly reviewed. This will be necessary if new equipment has been introduced or there have been changes to the ‘shop floor’ layout or working hours. For those companies with workers receiving exposures of 85dB(A) or above, your health surveillance programme should highlight any workers whose hearing
deteriorates due to inadequacies in your noise control programme.