Dust And Air Quality Assessment

Dust and Air Quality Assessment Including Occupational Dust Monitoring

Dust is generally understood to be an aerosol of solid particles, mechanically produced, with individual particle diameters of 0.1µm upwards and can be a problem in almost any industry, from bakeries to building sites.

The hazards of dusts like lead, silica and cotton are well known, but there are many other substances which may be present in dust and are hazardous to health.It is recognised that exposure to any dust in excessive amounts can create respiratory problems. The COSHH Regulations apply to ‘substances hazardous to health’ and these include dusts of any kind, when present in a substantial concentration in air (COSHH regulation 2).

The HSE state that employers should not carry out any work which may expose their employees to dusts unless:

• They have made a suitable and sufficient assessment of the risks to health from the dust(s) concerned; and
• They have taken the necessary precautions before the work begins, to meet the other requirements of the COSHH Regulations.

Many substances which can create dust have been given occupational exposure limits under COSHH. Some substances have been assigned an Occupational Exposure Standard (OES) (e.g. Portland Cement) and others such as respirable crystalline silica, have been given a Maximum Exposure Limit (MEL). A full list of MELs and OESs is contained in the HSE Guidance Note Occupational exposure limits (EH40).

Sampling for many different types of dust is generally undertaken in accordance with HSE booklet General methods for sampling and gravimetric analysis of respirable and total inhalable dust (MDHS14/3). Two different types of sampling are commonly used:

• Personal sampling: The sampler is attached to the wearer within his or her breathing zone, and the pump is connected to it by a length of flexible tubing and worn on a belt, harness, or in a pocket. Personal sampling instruments are normally mounted therefore on the upper chest, close to the collar-bone
• Background Sampling: Fixed point sampling may be used to determine background levels of dust in the workplace, the samplers should be mounted at approximately head height, away from obstructions, fresh air inlets or strong winds.

Once dust samples have been collected onto pre-weighed filters, they can be re-weighed to determine the mass of dust collected for a known volume of air. If required, the filters can also be submitted to a UKAS accredited Laboratory for analysis for particular substances such as heavy metals. The results can then be compared to the MEL and OES outlined in HSE Guidance Note Occupational exposure limits (EH40).

Capabilities

CL Voelcker have experience in undertaking personal dust monitoring in a range of environments to provide clients with information to assess the health risks of dust in the workplace. We regularly undertake studies to assess employee exposure to ‘total inhalable dust’ and ‘respirable dust’ in accordance with HSE booklet General methods for sampling and gravimetric analysis of respirable and total inhalable dust (MDHS14/3).

Many different types of dust can be sampled using the methods detailed in MDHS14/3 although some substances require adaptations to the method including special filter media and different sampling heads.

Many of these investigations take the form of one or two days on site sampling dusts using Vortex Air Samplers to undertake both background and personal air sampling. We work to ensure that investigations are designed with the input of clients so that work undertaken meets both HSE guidelines and the requirements of the client.