Addressing Contamination Concerns For Vacuum Pumps In Food Processing Environments

Iain Cunningham, Food & Beverage Sector Manager at Elmo Rietschle, a Gardner Denver brand, outlines the challenges facing food processing plants using vacuum pumps in packaging applications, and offers a best practice approach to dealing with contamination risks, while optimising pump performance too.

For food packaging environments that use compressed air, these sites must adhere to the hazard analysis and critical control point (HACCP) principles. HACCP is a way of managing food safety hazards, which looks closely at a business’ operations, what could potentially go wrong and what risks there are to food safety.

On this basis, critical control points that the business then needs to focus on can be identified, ensuring any risks are either removed or reduced to an acceptable level.

This enables the business to decide on what action needs to be taken if something does go wrong, while making sure procedures are being followed and working correctly, as well as ensuring the appropriate records are being kept, documenting any issues that arise.

Because compressed air is covered as part of the HACCP principles, it is clear where everyone’s responsibilities lie. However, there is no such guidance when it comes to the use of vacuum pumps.

Contamination risks of vacuum packaging

Vacuum packaging is a key process in the food manufacturing industry. A food preservation technique used with multiple food products, vacuum sealing is most commonly applied to fresh, processed and frozen foods, removing oxygen from the packaging holding the product and protecting its contents from contaminants and decomposition.

For all its benefits, however, vacuum packaging presents a difficult challenge, as it can potentially introduce the risk of contaminants – such as dust and droplets of oil – coming into contact with food.

However, because a vacuum pump is a small commodity item, typically hidden away out of sight, it will often be ignored until the equipment breaks and needs to be repaired or replaced. Nevertheless, the same HACCP principles should really be applied to the vacuum packaging process, as they are with the use of compressed air.

Without these safeguards in place, there is still the potential risk that food could be contaminated by a faulty vacuum pump that has not been maintained properly.

The vast majority of vacuum pumps are oil lubricated. As the vacuum pump sucks air out, this air needs to exhaust somewhere. Filters are installed to absorb the oil, but there is only so much they can take before they become saturated.

In some cases, due to a lack of servicing or issues such as badly fitting or failing separators, the filters can become blocked, meaning that oil bypasses the filters and blows out of the back of the pump.

Oil droplets then circulate in the air of the food environment, likely contaminating food. Even worse, an oil-lubricated lamp that starts to smoke could lead to a fire.

To avoid potential problems with air contamination around food, one solution is as simple as moving the machine away from direct contact with the production area, behind a wall or above a ceiling. Basic processes such as cleaning and the environment around the machine are also important to the pump’s performance.

There is an additional danger that food carryover could get into the pump’s oil filters and washing down with harsh chemicals can likewise cause parts inside the pump to corrode.

Overcoming pump pitfalls

The first way to ensure that you avoid the common pitfalls around vacuum pumps in food packaging is to fit downstream oil filters to act a further safeguard against accidental food contamination from the failure of blocked filters. This will, in turn, prevent the carryover of oil into the environment.

Equally, it is often poor maintenance – or inadequate maintenance practices – and minor equipment faults that risk oil discharging from the exhaust and the potential for oil contamination from oil-lubricated vacuum pumps.

This points to timely maintenance as an effective way to avoid potential contamination, ensuring that pumps run properly with very little or no oil carryover, while increasing pump efficiency and life expectancy.

Even with a high level of care and due diligence, however, tiny amounts of lubricant can come into contact with a food contact surface, the packaging or the food itself. Therefore, choose food grade or incidental contact lubricants, as they are specifically designed to meet strict regulatory limitations.

It is also important to use genuine spare parts for pumps. Oil-lubricated vacuum pumps run the risk of oil being discharged from the exhaust, and there is a chance the separator element may fail due to disuse, a poor fit or poor quality. Genuine parts will dramatically reduce the risk of this happening, ensuring a longer operational life than if non-genuine spares are used.

Finally, the ultimate way to avoid the issues associated with oil-lubricated pumps is to go oil-free. On the face of it, looking to change from oil-lubricated pumps to oil-free ones could seem to be an expensive undertaking.

However, when the additional performance capabilities of an oil-free pump are taken into account, as well as the reduced maintenance costs, it quickly comes apparent how oil-free technology could be an attractive proposition for many food manufacturers.

Specifically developed to meet the needs of manufacturers requiring only the highest air purity standards, oil-free pumps do not require the same level of maintenance as oil-lubricated models, as there is no need to replace oil or filters.

This also provides the added benefit of cutting down on maintenance costs over a pump’s lifetime. Another major advantage is that the oil-free pump does not have to be removed to carry out maintenance, so there is a considerable reduction in equipment downtime and the associated costs from oil, waste old disposal or labour.

A long-term investment

Every food manufacturing plant is different, and factors such as the configuration and age of machinery will have an impact on the best vacuum solution to meet a site’s packaging needs. While companies will have different priorities, all can do something to help minimise the risks of vacuum pumps contaminating the food packaging environment.

Ultimately, food manufacturers should view a vacuum pump as a long-term investment. Plants will require a wide range of different vacuum levels, depending on what is being sealed and how. The chosen vacuum pump can have a big impact on the efficiency and effectiveness of a system, but this is often not a consideration. 

Therefore, it is worth bearing this in mind when specifying a new vacuum pump, and then investing in regular maintenance throughout the pump’s lifetime, to ensure the system continues to operate as expected. This will help minimise contamination risks, while optimising the pump’s performance in the long run.