Poor ventilation of work spaces has left employees in many industries exposed to unacceptable levels of airborne contaminants, according to the Building & Engineering Services Association (B&ES)
High profile legal cases have brought the issue of workplace ventilation back into the spotlight in recent months. The Health & Safety Executive (HSE) has issued a number of enforcement notices on employers who have failed to meet their legal responsibilities to keep their staff safe. People working with wood, and in foundries and construction are considered to be at particular risk.

Too many employers still have only a vague understanding of the link between exposure to airborne contaminants and diseases that can affect their staff. Many serious health conditions only become apparent in later life - often after workers have retired.

Local exhaust ventilation (LEV) systems play a crucial role in attempts to reduce exposure to potentially harmful materials, but many are poorly installed, ineffective or are losing their effectiveness through lack of maintenance. The HSE says that poor maintenance of LEVs 'leads directly to industrial disease' and directs employers in at risk sectors to its guidance HSG 258 'Controlling airborne contaminants at work'.

There are around 140,000 LEV systems installed in the UK and it is estimated that 10 per cent of British businesses include processes that could increase the risk of contracting a respiratory disease. About 500,000 people rely on LEVs to protect their health in their workplace, but according to the HSE, only 40 per cent of installed LEVs are tested annually as required by COSHH Regulation 9.

Instances of occupational lung diseases, including asthma and Chronic Obstructive Pulmonary Disease (COPD), caused by exposure to dust, fumes and other airborne contaminants in the workplace remain unacceptably high. 1,500 people contract occupational asthma every year.

'Health and safety law says you must assess the risks to your workers from hazardous substances - dusts, fumes, vapours, etc. - and decide what measures to use to protect their health,' says the HSE. It reminds employers that they have 'a legal responsibility to ensure that employee exposure to dust/fumes etc. is minimised and well controlled. LEV is an excellent way of doing this'.

It is more important than ever that the companies who supply, examine and maintain LEV are competent and that end users demand proof of that competence otherwise their LEV may not work properly.

The B&ES Local Exhaust Ventilation group was set up to ensure the right mix of skills, knowledge and experience are available across the industry and to prepare appropriate guidance. Its members urge LEV users to ask contractors about their qualifications and training, experience and previous work. A competent supplier should be able to supply references and/or testimonials.

B&ES is producing technical guidance for all owners and maintainers of this type of equipment. This will set standards that will help workplace managers achieve the internal air quality they require. It will establish a quality threshold against which all firms operating in the LEV market will be assessed and forms part of the independent Inspection and Assessment regime operated by the association to establish the quality of all of its members. Visit www.b-es.org for more details.

The group also urges the use of airflow indicators. These are not a legal requirement in themselves, but are an effective way of demonstrating if the LEV is working properly and, therefore, that the user is meeting their legal obligations. Airflows can be affected by a number of factors including poor maintenance leading to blocked filters; build up of materials in the system; or damaged ductwork.

There are other ways of checking airflow such as using an anemometer, or a dust-lamp or smoke tracer while the work station is in use. However, an airflow indicator is currently the only method that will show the operator or supervisor immediately if there's a problem. Therefore, HSG 258 recommends their use.

A thorough examination and test should also be carried out at least every 14 months and the records kept for at least five years.

Receiving greater priority

High risk industries are receiving greater priority through the HSE's Industrial Disease Reduction Programme as it looks to concentrate reduced resources in areas where they can make most impact with support from relevant trade organisations. B&ES ran a series of seminars on the subject for practitioners and end users.

There has also been a problem with mis-selling. LEV equipment is regularly sold on price only and several B&ES members have pointed out that some systems carry CE marks, but are not fit for purpose. Often end users have been sold an over-expensive, ineffective LEV, when a competent specialist firm could have installed something that cost considerably less, but worked very much better. Many systems are also never properly commissioned.

Schools are also at risk. There is a worryingly large proportion of poorly specified LEVs fitted classrooms. B&ES member firms are working hard to reach these systems and ensure they are cleaned, repaired, re-commissioned and/or replaced.

So, in general, what should contractors and owners be looking for?

In a large number of cases, the LEV hood is not matched to the process causing exposure and suppliers fail to provide adequate guidance to their customers. Airflow indicators will quickly show if there is a problem. The process operator can see at a glance if the LEV is effective.

Where problems are found, prompt action should be taken to restore the LEV's effectiveness by, for example, replacing components such as the filter, clearing any blockage or simply closing some extraction points if too many are open.
Employers must provide training so their staff understand how the LEV works and what it is for. When they recognise there is a problem, they need to employ competent ventilation contractors to put things right.

A competent supplier should be able to provide details of their qualifications, training and experience as well as references or testimonials, which is a key recommendation of the B&ES guide to good practice.

LEVs can provide a high level of workplace health protection, but only if they are appropriately designed and then properly installed, commissioned and maintained. It is important that employers don't take the easy - or cheap - route to try and meet their legal obligations. The long-term health and welfare of workers is far too important.