Employees working in the confined environment can often be at higher risk from exposure to hazardous substances than others. The confined environment has a limited means of ventilation and hazardous substance can accumulated rather quickly. We have carried of fume testing of lift shaft engineers in a high-riser building in central London. Our task was to evaluate if the employees working in the lift shaft are being exposed to volatile substances at concentration hazardous to health.
The operatives working in the lift shaft were carrying out a routine maintenance of lift cables. The work involved application of hydrocarbon based lubricants to the lift cables using and brush rollers or simple paint brushes. The workers work on top of the lift and start applying lubricant on top of the lift shaft and work their way down. The lubricant used in this process contain significant proportion of volatile hydrocarbons which quickly evaporate thus thickening the applied solution. The lift shaft themselves are fairly enclosed with limited amount of ventilation. We were also investigated whether a portable air filtration system would have a significant effect on the operatives exposures.
We have fitted two operatives with sampling devices to carry out fumes sampling and to evaluate their personal exposures during application of the products. The specific product used in this situation contained mainly unspecified petroleum hydrocarbons and some unspecified anti corrosion additives and preservatives.
Our fume testing shows that the personal exposure of the lift engineers was not as high as expected. The typical exposure levels were about 1/10th of the workplace exposure limit. We have also ascertained that the use of activated charcoal portable filter in the close vicinity of the lift engineers had only marginal effect on the overall exposure. The personal exposure level of operatives with the air filtration present was reduced by about 10% in comparison to the test without filtration.