Improving Air Quality from Vacuum Pumps

October 27, 2016
Gareth Topping

Consider the purity of exhaust air emitted by vacuum pumps in addition to the purity of compressed air used in the pharmaceutical process.

Compressed air used in pharmaceuticals manufacturing is held to the highest possible standards. However, there is currently a risk that sites may be overlooking another potential source of contamination-the exhaust air emitted by vacuum pumps.

Air quality
Few major industries in the world place a greater level of importance on hygiene and avoiding contamination than pharmaceuticals manufacturing. Stringent standards regulate the quality and specification of the compressed air used throughout manufacturing sites, most notably ISO8573 (1). The nine parts of this ISO standard detail the amount of contamination allowed in each cubic metre of compressed air and specify the methods of testing for a range of contaminants, including oil and viable microbial contaminants.

As well as making sure that they are compliant with ISO8573, an increasing number of pharmaceutical sites follow the principles of the Hazard Analysis Critical Control Point (HACCP). Originally designed for use in the food manufacturing industry, these principles ensure that sites are complying with hygiene legislation and either eliminating any potential hazards or reducing them to an acceptable level.

Yet, while most manufacturers spend countless hours making sure that their direct production processes are scrutinized in great detail, ancillary processes and utilities can often be skimmed over or even omitted entirely. Despite the comprehensive standards for the quality of the compressed air, there are no matching standards covering the exhaust air being emitted by the system’s vacuum pumps. As these vacuum systems will generally be located around the production environment, a contaminated pump exhaust can cause major hygiene issues that completely undermine the time and effort spent ensuring that the compressed air itself is pure.

Potential risks
The majority of vacuum pumps currently in use throughout the pharmaceuticals industry are lubricated with oil. These pumps have been the standard for many years and most will be perfectly reliable. Nevertheless, poor maintenance practices or minor equipment faults can create the risk of oil discharging from the exhaust. In addition, if the system is operating at high temperatures with an open-ended inlet port, oil could carry over from the pump. A separator element, which removes any oil particles remaining in the air, may also fail due to misuse or through the use of non-genuine spare parts.

If a system is well maintained, then the chance of any contamination is already low, but eliminating the potential risk of leaks from an oil-lubricated vacuum pump can be achieved through a range of measures. These include using a specialist food-grade lubricant to reduce the impact of any potential contamination, fitting a downstream exhaust filter, or remotely piping the exhaust air.

While reducing the risks associated with oil-lubricated vacuum pumps is comparatively straightforward, the sensitive nature of pharmaceuticals production means that for some companies it may make sense to implement an oil-free model instead.

Oil-free vacuum pumps have been developed specifically to meet the needs of manufacturers that require only the highest air purity environments. They generally require a slightly higher up-front investment. However, there is no need to replace the oil or filters because they do not require the same level of maintenance as oil-lubricated models, which may generate savings over the course of a pump’s lifetime. In addition, an oil-free vacuum pump does not have to be removed to carry out essential maintenance servicing, so there is no equipment downtime and no associated costs from oil, waste oil disposal, or labor.


1.    ISO, ISO 8573 Compressed Air(Geneva, Switzerland, 2010).

About the author
Gareth Topping is sales manager at Gardner Denver,