Avoid the slippery slope of disaster through lubrication risk management

Its potential to be an unwanted source of contamination for foodstuffs means that lubrication continues to be a key topic within the food industry.

Without proper lubrication, most machinery will break down over time, which is not only true of food manufacturing equipment but across all other sectors too. The difference within the food industry is that the lubricants used not only have to provide good technical performance but also to address the issues of cleanliness, contamination prevention and health and safety.

What are the risks?

All food producers are keen to avoid any contamination incidents, which can lead to product recalls, bad press and costly court cases. The correct choice and application of lubricants can make a significant contribution to ensuring that harmful contamination is avoided during the manufacturing process.

Components such as line lubricators, slide and roller bearings, chains, compressors, vacuum pumps, gearing, heat transfer systems, hydraulics and pumps are commonplace in food production plants. Many of these are found in close proximity to the foodstuffs, often with a high potential for any leaked lubricant to make incidental food contact. For example, high-pressure hydraulic hoses often run alongside production lines, while motors and gearboxes are frequently located above the lines.

More demanding legislation and higher hygiene standards, such as the Hazard Analysis and Critical Control Points (HACCP) concept, allow users to clearly identify lubrication points where there is a possibility of foodstuffs becoming contaminated.

In the event of a contamination issue, regional legislation states that a food manufacturer is liable unless able to demonstrate that every possible step has been taken to prevent the contamination. 

A well-reputed lubricants supplier can assist with HACCP surveys, making it possible to identify lubrication points where there is a risk of contamination, leaving manufacturers with action points on how to minimise the risks as well as advice on the correct lubricant to use.

International Standards for food-grade lubricants

By using food-grade lubricants, food processors can avoid having to discard whole batches of product in the event of incidental food/lubricant contact.

However, despite regulations governing food hygiene being implemented in December 1995, there is still no detailed global or European standard for food-grade lubricants. It is therefore normal practice to rely on the US standards issued by the Food and Drug Administration (FDA) and the US Department of Agriculture (USDA). When the USDA ceased registration of lubricants in 1998, the function was taken over by NSF International, a not-for-profit independent organisation, previously known as the National Sanitation Foundation. Registration with NSF allows the use of the highly recognised and credible NSF registration mark on products.

Around five years ago, a second registration body was introduced in Europe (UK) called InS Services. The main intention was to counter the product registration market dominance held by NSF International. This may be confusing for food manufacturers, as they now have to search two different product listings to ensure their lubricants are food safe.

However, well-reputed lubricant manufacturers still rely on NSF International for product registration purposes, although this route may be slightly more intense and costly. The reason is the reputation of NSF, its global recognition and the fact that they are experts in other food and beverage safety areas as well, such as HACCP.

As already highlighted, the specification for food-industry lubricants is not governed exclusively by technical considerations. 

Performance and FDA restrictions are not the only criteria significantly influencing formulation chemists in their daily work. More and more food manufacturers are asking for proof of many other things and to provide:

• Religious certificates like Halal and Kosher
• Proof of the absence of GMOs (genetically modified organisms)
• Proof of the absence of BSE/TSE virus
• Proof of the absence of allergens (Guideline 2003/89 EC).

Machinery and component manufacturers are also setting their own standards, based on the widely accepted US guidelines, regulating additives and base oils in the formulation of food-compatible lubricants to be used in their equipment. Throughout the industry in general, the majority of original equipment manufacturers (OEMs) now recommend lubricants which meet international standards such as ISO, DIN, IP and ASTM. Obviously these standards also need to be attained in lubricants designed specifically for the food industry, and equipment and lubricant manufacturers working closely together can only achieve this.

OEMs can be divided into manufacturers of production equipment and manufacturers of components. Manufacturers of production equipment and machinery usually provide their customers with a list of suitable lubricants. The lubricants recommended are usually those which have already been proved safe for use in the food industry. Such recommendations are often based on experience gained in the field by machinery and lubricant manufacturers. 

Manufacturers of components, such as hydraulic pumps, transmissions, bearings and seals, tend to recommend lubricants which meet the international standards and have also passed further in-house tests. However, these tests and the standards applied to the lubricants by component manufacturers can fail to take into account the special requirements of the food sector. They do not always verify whether substances are certified as food-compatible, nor do they account for the unique manufacturing environment within the food industry.

Surveys conducted by lubricant suppliers of manufacturing plants provides manufacturers with information on whether the lubricant needs to be food grade or not, and the most suitable lubricant for the application.

Certification of production and plants

Although the same production facilities can be used for food grade lubricants as well as standard products, more stringent rules are applied in order to achieve the highest purity levels and avoid the possibility of cross contamination.  Production facilities such as conduits, mixing vessels and bottling plants must be certified to ISO 9001/14001, as a minimum, for the manufacture of food-compatible lubricants. Some lubricant manufacturers have even carried out their own lubricant critical control points (LCCP) analysis, and use food grade lubricants in their manufacturing plant.

About 10 years ago, the National Lubricating Grease Institute (NLGI), the European Lubricating Grease Institute (ELGI), the European Hygienic Engineering and Design Group (EHEDG), and NSF have coordinated a project to enable lubricant manufacturers to undergo independently audited HACCP exercises. The final result was the launch of a new standard called “Safety of Machinery – Lubricants with incidental product contact – Hygiene requirements”. The final standard was published in 2006 under ISO 21469.

There is a significant difference between product registration only and ISO 21469 certification. The ISO 21469 consists, on top of the product registration, of a full risk assessment for the entire lubricant manufacturing plant and a physical yearly audit, which includes formulation review, process review and sample taking and testing. Therefore, ISO 21469 represents today the highest standard for food safety, specifically dedicated to manufacturing and handling of food grade lubricants.

The final certification links products and manufacturing plants together in all cases. There are currently nine companies (including subsidiaries) with 11 different lubricant manufacturing plants certified against this standard by NSF.

Comparative performance of food-grade lubricants

Food manufacturers, OEMs and lubricant producers continue to work towards improving the performance of food-compatible lubricants. Although there has tended to be a degree of geographical variation, the historic opinion was that lubricants for the food industry did not match the performance levels of standard lubricants. However, there have been significant developments over recent years, with the leading lubricant manufacturers working closely with OEMs and the food industry to provide high-performance lubricants.

Manufacturing processes and equipment are designed and developed with hygiene as a key consideration. The lubricants need to be designed as part of the overall specification, and the constraints in specifying lubrication systems are likely to be more restrictive than in other industrial sectors. Until recent years, the formulation chemist was severely restricted by the limited number of permitted additives and base oils, and as a result it had not always been possible to achieve high levels of lubricant performance.

Synthetic base oils like polyalphaolefins, esters, glycols, silicon oils and polyethers are being increasingly used, and considerable progress has been made in refining white oils – practically the only base oils used in food applications for decades. Additive technology has also progressed significantly giving formulation chemists much greater scope to improve performance whilst working within the stringent guidelines governing food-compatible lubricants.

As a result, modern lubricants for the food industry now achieve performance profiles at least as high as those of conventional synthetic lubricants.

‡ Excellent † Good ♦ Fair/satisfactory.

Food-grade lubricants in action

As it is used, a food-compatible lubricant is exposed to a number of influences, such as oxidation, heat, humidity and a decline in its lubricating properties. Ongoing monitoring of lubricant condition is important in any industry, but it has particular significance in the food sector. 

It is important to remember that the analyses and information regarding the toxicity of lubricants, and the additives they contain, relate to new lubricants before they have been used. 

The equipment in food manufacturing plants does not differ significantly from that used in other industries, but the environment in which it operates presents a number of unique and complex challenges. The necessary daily washing of machinery with aggressive cleaning products under high pressure increases the chance of lubricant contamination, and highly reactive substances such as fruit juice can degrade oils and greases. The industrial processes often operate at extremes of temperature, ranging from freezer systems to high-temperature ovens.

Even under these conditions, manufacturers must ensure that the lubricants used continue to fulfil their primary functions, including lubricating machinery and components, heat dissipation, wear protection, friction reduction and corrosion protection. In the food industry, oil-change intervals depend more on the contamination of the lubricant than on the reduction of its lubrication properties through the degradation of additives, or oxidation of the lubricant.

In addition, it is possible that lubricant can become contaminated by external influences such as water, dust and cleaning products, which can cause reactions. Not only do these reaction products pose potential contamination hazards, but they can also have a damaging effect on the production plant. The useful life of the oil is reduced and premature wear must be avoided through more frequent oil changes. Taking and analysing oil samples can only accurately assess the level of lubricant degradation. 

Regular analysis of samples from transmissions, compressors and hydraulic power units reveals the wear patterns in key machinery components and allows an examination of the chemical and physical condition of the lubricant, including any impurities and contamination. It is important that personnel responsible for administering lubrication management systems are trained, and customers are usually keen for lubricant suppliers to organise seminars for their plant operating teams.

Today’s superior lubrication products carry all of the necessary certifications and registrations required for the food and beverage manufacturing industry. Combined with carefully planned and implemented lubrication maintenance schedules, plus expert technical support and training direct from the lubricant manufacturer, well-reputed suppliers provide food manufacturers with the ultimate peace of mind, knowing that they have minimised the risk of product contamination