Exposure to substances hazardous to health in the workplace
Our next project took us to Northampton where we conducted an assessment of occupational exposure to hazardous substances in a factory. The factory of concern specialised in the manufacturing of small rubber and plastic components for the automotive and oil industry. The manufacturing site is split into three main production buildings. One production building houses moulding machines, assembly areas, offices and welfare facilities. The second production building houses plastic injection moulding machines and an assembly area and the third production building is used for the storage of materials.
Approximately 80 operatives are employed throughout the factory and they are expected to be exposed to hazardous substances for 11 hours during a typical working day. Operative working in the rubber injection moulding, work mainly with Polychloroprene, EPDM (ethylene propylene diene monomer) and natural rubber which are moulded to produce the products. Therefore employees working in this area are likely to be exposed to fumes from the rubber moulding process. All the machines and inspection tables within this area are equipped with dedicated local exhaust ventilation systems in order to control the fumes produced.
Operatives working in the compression moulding area carry out the machine safety check in the morning and then cleans the machines with a knife or a brush, as required. The moulding tool is sprayed with soup solution to prevent sticking. The operative inserts a rubber or silicon based blank into the moulding tool and activates the machine. This process is then repeated across further 5 machines. Once the moulding process is completed, the mould is taken out to an inspection table and trimmed as necessary. The process of removing the mould is then repeated on the next machine, thus completing the production cycle. There is currently no effective local exhaust ventilation installed in this area.
How to minimise exposure to hazardous substances within the workplace
By fitting operatives with Cassella and Gillian personal samplers we were able to collect samples of airborne particulates and vapours present in the air while performing typical work activities. Air monitoring results suggested that the operatives are unlikely to be exposed to levels of rubber dust and rubber fumes above the workplace exposure limits (WELs). However the personal exposure of operatives working with the injection moulding machines marginally exceeded the 50% of workplace exposure limit for rubber fumes. Therefore we recommend the efficiency of the LEV system is checked and the employees’ working habits are observed in order to establish a cause of the elevated exposure. Although the personal exposure was elevated, none of the employees were exposed to levels of rubber fumes or rubber dust which we could be considered hazardous to health.
Once air monitoring was complete our surveyor was able to recommend the most suitable remediation measures. Our surveyor concluded that the contaminants within the workplace were being adequately controlled so the use of respiratory protective equipment is necessary nor is a formal health surveillance programme. However he strongly recommends that a LEV system is installed in the compression moulding area. It is also recommended that all employees are trained on the safe use of hazardous substances in the workplace, the recommended control measures and all associated health issued. Refresher training should be provided at least once a year.