Take some sound advice

Laboratory noise is subject to the same health and safety framework as noise in any other workplace. In this article Bob Bonnington outlines some key aspects of the legislation and what laboratory managers can do to protect laboratory staff and users from harm, and themselves from prosecution.

Laboratories are often noisy places and laboratory managers must ensure the health and safety of staff and other users is not being put at risk through exposure to excessive noise levels in the workplace.

The primary legislation in the area of occupational health and safety is HASAWA (Health and Safety at Work etc Act 1974). The act seeks to secure the health, safety and welfare of people at work and protect others (such as students, visitors, and members of the public) from risks to their health or safety caused by the activities of persons at work. The act places employers under a general duty to ensure, as far as is reasonable practicable, the health, safety and welfare at work of their employees and others whose health and safety the works may affect. The act also empowers the Secretary of State to make regulations from time to time.

Since HASAWA came into force a large number of regulations in respect of occupational health and safety have been made. The MHSWR (Management of Health and Safety at Work Regulations 1999) and CNAWR (Control of Noise at Work Regulations 2005) were made in this way. Employers are required by MHSWR to introduce measures that ensure risk to health and safety in the workplace is properly assessed and managed.

The regulations specific to noise are CNAWR. These regulations are intended to protect workers from the health risks of hearing damage and from safety risks that may arise where noise interferes with the ability of someone to hear instructions or warnings.

In support of these aims, CNAWR define a daily or weekly lower exposure action value of 80dB (A-weighted), and a daily or weekly upper exposure action value of 85dB (A-weighted). In addition the regulations specify a daily or weekly exposure limit value of personal noise exposure of 87dB (A-weighted) experienced while wearing personal hearing protection provided by the employer. The employer must not allow any employee to be exposed above an exposure limit value. (Peak sound pressure values for use in respect of impulse noise exposures are also given in CNAWR).

The regulations require any employer who exposes an employee to noise at or above the lower exposure action value to carry out a suitable and sufficient risk assessment. The purpose of the assessment is to identify the actions needed to comply with the CNAWR.

In short CNAWR require an employer to carry out a risk assessment, eliminate or control noise risks, provide hearing protection (where appropriate), give workers information and training, subject individuals at risk to health surveillance, and undertake periodic reviews of risk assessments. There are many laboratories where the ambient noise levels are similar to those found in busy offices. The noise in such spaces is a bi-product of human occupation, and the operation of computers and printers, air conditioning, and laboratory equipment.

In such spaces occupants can communicate with ease and people experience little or no difficulty in making the meaning of their message clear or in understanding what has been said. The noise is neither intrusive nor distracting. Generally such conditions do not represent a risk to the health or safety of laboratory users. Laboratory managers should record in their general health and safety risk assessment under MHSAWR that noise does not represent hazard in such a workplace.

Those who find themselves responsible for such laboratories are fortunate. The low noise levels and hence exposure to noise is likely to fall well outside the criteria laid down in the CNAWR. However laboratory managers should continue to monitor noise levels within their laboratories to ensure compliance with HASAWA and MHSAWR. Monitoring can easily be done on their routine management visits. When an increase in noise levels is noted managers should establish the cause and take action when appropriate. The likely impact on noise levels of new equipment should be evaluated before it is purchased and installed. Where a choice exists then quieter equipment should be chosen over noisier equipment.

There will be laboratories where the background noise levels are high. In such circumstances laboratory managers must decide whether the health or safety of laboratory staff or users is at risk. To establish whether this is the case managers must undertake a CNAWR risk assessment. The risk assessment comprises five steps: identify the nature of the hazard; identify who might be harmed and how; develop a plan to control the risks; record the findings of the assessment; and check the risk assessment remains valid over time or in the presence of changed circumstances. Completion of the first step will show whether it is necessary to proceed and complete a full risk assessment.

Laboratory managers may find the answers to the following or similar questions helpful when considering the first step. Do those working in the laboratory need to shout above the background noise to be understood by colleagues standing two metres or less away? Does any employee spend more than 30 minutes a day exposed to such background noise levels? Do laboratory users operate noisy power or impact tools in the course of their work?

If the answer to any of these questions is ‘yes’ then there are probably noise risks the manager will need to address and the manager should proceed to complete the remaining four steps of the CNAWR risk assessment. While some laboratory managers will have the necessary skills and knowledge to assess and manage noise risks others may not. In these circumstances it is essential such managers engage someone who is competent to carry out the risk assessment and is able to make recommendations regarding control measures. Alternately managers could acquire the necessary skills and knowledge through training. The Institution of Occupational Safety and Health and the Institute of Acoustics both offer suitable courses.

Laboratory managers should use organisational or technical means to either eliminate the noise or to control it at source. Controlling noise at source reduces the number of people in the surrounding area who may be exposed to excessive noise. This approach in turn will reduce the number of times personal hearing protection must be worn and so reduce the exposure risk further.

There are a number of things laboratory managers can do to control the exposure of people to noise. Managers should consider whether the work could be done in a way that would eliminate or reduce the exposure of laboratory staff or users to noise - perhaps the noise source could be placed in a separate acoustical enclosure or an unoccupied room to which access is controlled. In difficult cases the help of someone qualified in noise and vibration control should be sought.

Personal hearing protection can play an important part in the risk control programme of a laboratory. It is important laboratory managers realise they must provide staff with personal hearing protection on request if staff are exposed to noise at or above the lower exposure action values of daily or weekly personal noise exposure of 80dB(A) but below the upper exposure value of daily or weekly personal noise exposure of 85dB(A).

Personal hearing protection must be introduced immediately laboratory managers suspect staff or users may be exposed to noise at or above the upper exposure action value of daily or weekly personal noise exposure of 85 dB (A-weighted) in order to protect their hearing from possible injury or harm. The wearing of personal hearing protection in such circumstances is mandatory.

The wearing of personal hearing protection must continue until the technical or organisational controls introduced by the laboratory manager have proven effective in reducing the value of daily or weekly personal noise exposure to below the upper exposure action value. However, it may be the case that the wearing of personal hearing protection may need to continue in order to provide additional protection beyond that has been achieved through technical or organisational controls. All hearing protection must carry the CE mark.

So what key points should laboratory managers bear in mind? Where laboratory noise levels are less than the lower exposure action values and a CNAWR risk assessment need not be done. However the decision not to proceed (and the reason for not doing so) needs be noted in the MHSAWR risk assessment. Those laboratories with more demanding noise environments will require a full CNAWR risk assessment and a competent person must do the risk assessment and managers must act on the findings. By doing so laboratory managers will ensure their staff and other laboratory users are protected from injury and managers will avoid the emotional and financial costs of legal sanctions.

By Bob Bonnington. Bob is a freelance writer on occupational health and safety matters. He holds an MSc in Vibration and Noise Control and has over 30 years experience of managing buildings with complex engineering services.