Food grade lubricants: they’ve come a long way

Implementing food grade lubricants without sacrificing performance or increasing operating costs. By Colleen Flanagan

“There are many misconceptions when it comes to food grade lubricants”
-Colleen Flanagan

In order to ensure food product safety, many food processors have adopted or are in the process of implementing the Hazard Analysis Critical Control Points (HACCP) system.

The HACCP system requires that points where lubricants and food products could come in contact during various manufacturing processes must be analyzed for potential hazards. For these processes, H1 food grade lubricants and greases should be used in equipment such as hydraulic systems, pumps, mixers, tanks, chain drives and even seaming units to reduce the risk of incidental contamination by non-food grade lubricants.

There are many misconceptions when it comes to food grade lubricants, including:

• Food grade lubricants do not last as long as non-food grade lubricants;
• Food grade lubricants do not protect equipment as well as non-food grade lubricants;
• Using food grade lubricants adds significant costs to operations;
• For tough applications, only non-food grade lubricants can be used;
• All food grade lubricants are the same.

This article will look at proper food grade lubricant selection and key criteria to consider during the selection process for major applications. These criteria can be evaluated using standardized laboratory tests. 

Food grade hydraulic fluids
When selecting a food grade hydraulic fluid, here are three key properties to consider. Fluid Life - Oxidative & Thermal Stability: resistance to oxidative and thermal breakdown keeps systems free of sludge and varnish to ensure smooth and reliable operation of hydraulic valves and actuators. Wear Protection: a hydraulic fluid should protect metal pump parts from scuffing and scoring, and reduce overall maintenance costs by extending the life of the hydraulic system. Resistance to Foaming and Air Entrapment: a hydraulic fluid should prevent reservoir overflow and eliminate 'sponginess' from hydraulic systems and damage caused by pump cavitations.

Food grade compressor fluids
When selecting a food grade compressor fluid, here are four key criteria to keep in mind. Fluid Life - Oxidative & Thermal Stability: for a compressor fluid, resistance to oxidative and thermal breakdown guards against oil thickening, and deposit and sludge formation. It also extends fluid life, which saves on costly change-outs, downtime and oil disposal costs. Wear Protection: protection against wear will extend the time between compressor overhauls and reduce overall maintenance costs. Low Oil Volatility: lower oil carryover also reduces sludging and deposit formation in air-oil separators, as well as storage tank and lines, which ultimately lowers maintenance costs. Rust and Corrosion Protection: fluid that provides rust and corrosion protection can extend compressor life, resulting in reduced downtime and possible repair savings.

Food grade gear fluids
When selecting a food grade gear fluid, here are four key criteria to consider. Load Carrying Capability and Wear Protection: higher load carrying capability prevents seizure, scuffing and spalling, even under shock loading conditions. Life of the Fluid - Oxidative and Thermal Resistance: keeping gearboxes free of sludge and varnish results in longer fluid life and reduced downtime, even at high temperatures and in the presence of water and acidic contamination. Resistance to Foaming and Air Entrapment: foaming and air entrapment resistance prevents reservoir overflow and gear damage caused by insufficient lubricant film due to aeration. Resistance to Contamination: a gear fluid should provide rapid separation from water.

Food grade greases
When selecting food grade grease, there are four key criteria to keep in mind. Resistance to Lubricant Breakdown in Harsh Operating Environments: food grade grease should maintain consistency and lubrication in the presence of food acids, juices and by-products. Effectiveness Across a Wide Range of Temperatures: food grade grease should not run from bearings operating at high temperatures, yet should remain pumpable at low temperatures. Load Carrying Capability and Wear Protection: food grade grease should prevent seizure, scuffing and spalling under shock loading conditions. Rust and Corrosion Protection: food grade grease should prevent bearing, gear and equipment damage in moist or wet operating conditions.

When selecting food grade lubricants, it is important to work with your lubricant supplier. Start by explaining your operating issues to find a solution that will decrease your overall operating costs.

Colleen Flanagan is Category Manager (Food Grade Lubricants) at Petro-Canada. She has over 20 years of experience in the oil and lubricants industry, the majority of which has been in the downstream sector with Petro-Canada. For more information please visit www.lubricants.petro-canada.ca.