Avoiding contamination risk from mechanical seals
Eliminating the risk of contamination is high on the agenda of every responsible food and drink producer. Yet many pumps on production lines are fitted with mechanical seals which fail to comply with EU regulations. Paul Green, of AESSEAL, explains how mechanical seals can pose a hidden, but serious, contamination risk, and suggests how non-compliance can be avoided.
Mechanical seals are a key component of food and drink manufacturing equipment, fitted to pumps at any point along the production line.
The requirement to keep production line equipment free of contaminants is well understood and stringently adhered to by responsible producers.
However, there remains a lack of awareness about the full implications of some key pieces of legislation, including the FCM regulation, which covers materials and articles intended to come into contact with food, and Regulation (EC) 2023/2006 on good manufacturing practices for materials and articles intended to come into contact with consumables.
This can mean that mechanical seals manufactured from non-safe materials are routinely specified, despite the fact that they come into contact with food or drink, risking contamination and creating a potentially serious health and safety issue.
In food and drink manufacture, mechanical sealing solutions are needed to effectively seal rotating equipment to prevent leakage and to seal thick sticky slurries and solutions capable of withstanding clean-in-place (CIP) procedures. They are a vital part of ensuring processing equipment and machinery continues to run reliably and that food ingredients remain free of contamination.
The regulations relating to mechanical seals in these processes couldn’t be simpler: every component must be 100% traceable and a statement of compliancy must be clearly marked on the packaging it comes in.
So, how might potentially unsafe seals be installed on production lines which otherwise have highly stringent safety mechanisms in place?
The answer lies in the complexity of source materials and supply chains, often compounded by lack of awareness, poor communication and simple force of habit.
Many mechanical seal faces are made from carbon. There are around 15 grades of carbon commonly used, of which only a handful are compliant with Food and Drug Administration (FDA) standards. Of the remainder, some are suited to chemical applications and don’t require FDA compliance and, finally, there are antimony carbons, which are used in the oil and gas industry and, put simply, are poisonous.
It seems blindingly obvious that this type of seal should never be used anywhere near the food supply chain, but the reality is that we have seen this type of antimony carbon on sites where the implications of it being misapplied could be disastrous.
The problem with these unsafe materials is that they all look exactly the same as a seal which is 100% traceable and compliant. You simply cannot differentiate between the two, unless you have its traceability clearly stated on the box it comes in.
The potential risk implications of installing mechanical seals made from untraceable materials can not be overstated.
The more complex the food production process, the greater number of seals – some plants may have as many as 15 to 20 mechanical seals and 60 to 100 static sealing joints across the whole production line. A company that carries out stringent checks at every stage of production might be blissfully unaware that there are in fact a number of points of heightened contamination risk along that line – one for every seal.
Those responsible for compliance with FDA and EU regulations don’t always pass that information on to operatives at the lower ‘repair and replace’ end of the production line. And the need for expediency means that when repairs are required, the operative’s focus is on getting a production line back up and running rather than considering the compliance of the spare part being picked off the shelf.
An engineer or purchasing department buying component seals currently being imported into Europe from Asia might take it for granted that the Original Equipment Manufacturer (OEM) may have bought the product from the lowest cost source.
What they might not be aware of is that, to achieve this low cost, the product has often been through so many links in the supply chain that by the time it arrives at the end user all traceability has been lost. And if you have no traceability you have zero knowledge of the material the seal is produced from.
In particular, those brands who work with an external supplier to maintain their equipment find themselves dangerously far removed from compliance requirements, assuming – sometimes incorrectly – that the supplier has properly interpreted and implemented safety legislation.
But Regulation EC1935/2004 is clear – if that traceability is not visibly evidenced on the packaging, those claims carry no validity and the mechanical seal should not be installed on a food or beverage production line.
There is a simple solution to what effectively amounts to building risk in to production processes at the same time as breaking the law. Look at the label. And if the seal comes in packaging that doesn’t clearly state its source, don’t use it.
The food and beverage industry can rightly pride itself on its high levels of quality assurance and self-regulation, but the failure to understand or act on the laws and regulations around traceability and labelling is a serious chink in its armour.
We estimate that very few mechanical seals currently used in the food and drink industry actually comply with standards and are working to bolster awareness of the compliance requirements which impact processing equipment and machinery, to try and drive change within the industry.
The risk of contamination is very real – and with a solution so obvious and simple to implement there really should be no excuses for installing non-compliant mechanical seals in food production plants.
This article first appeared in the May 2021 issue of Industrial News.
