In the past, mineral oil based hydraulic fluids were used in many food processing operations due to their excellent performance properties and value. However, due to destructive and often tragic factory fires, demand for fire-resistant hydraulic fluids has grown rapidly. In response to this demand, companies are developing cutting-edge lubricants that possess all the requirements of a high-performing hydraulic fluid, without flammability or toxicity.
Many food processing facilities today are still using petroleum based hydraulic fluids near heat or flame, presenting the risk of fire and the loss of lives, product, equipment and property. One extreme example is the 1991 tragedy at the Imperial Foods Processing Plant in Hamlet, N.C., where a faulty modification to a hydraulic line led to a spray of flammable hydraulic oil onto a hot fryer, causing rapid ignition and spreading flames that killed 25 workers and injured 54 others. That was more than 20 years ago, but similar accidents continue to occur regularly. Most food plants by their nature require heat – for frying, grilling, scalding, canning, boiling, baking and more – so the risk of fire is never far. In the first eight months of 2013, there were over 32 fires in food processing plants in North America, many of which may have been prevented or quickly extinguished had the manufacturer been using a fire-resistant hydraulic fluid.
Finding Safer Fluids
All manufacturers require the highest performing lubricants to protect their equipment and maximize operational efficiency and productivity. Most hydraulic fluids are mineral oil based and considered flammable. Manufacturers whose operations include heat or flame should require that their hydraulic fluids be fire resistant – meaning that the fluids resist ignition and prevent the spread of flame in the case of an accident.
Such fluids are used in various industries, including food processing, steel making, foundry operations, mining, shipping and the U.S. military, with over 200 million gallons in operation across North America. FM Global, the worldwide commercial property insurer, subjects materials to rigorous testing and approves fire-resistant lubricants that are proven to reduce fire risks in factories. Manufacturers who adopt FM-approved lubricants and whose facilities undergo inspections to show full compliance with fire safety regulations can reduce their insurance premiums up to 50 percent.
Fire safety, however, is just half of the puzzle for food processors. The food industry also is required to use hydraulic fluids that are proven to be safe and suitable for use in and around food processing equipment. The U.S. Department of Agriculture created the main category of lubricants (called H1) that are suitable for use in the food industry, and the U.S. Food & Drug Administration restricted these food grade lubricants to contain only ingredients listed under 21 CFR 178.3570, 21 CFR 182 and 21 CFR 184.
Under these federal rules, H1 products must be used wherever incidental exposure to foodstuffs may happen – for example, where a hydraulic fluid could drip or spray into the food line. H1 hydraulic fluids must be colorless, odorless, nontoxic, and should cause no harm if accidentally ingested by consumers. Going further, the FDA warns that any foodstuff contaminated by a lubricant, even as low as 1 kilo in 100,000 kilos of food, must be destroyed or recalled swiftly from distribution.
Two independent organizations, NSF International and InS Services, review the formulations of H1 products, and each maintains an online registry of lubricants that satisfy all these requirements. The registrations are based on the potential for various levels of food contact.
Food Processings Burden
Taken together, all of these requirements impose an additional burden on food processors not only to use lubricants that effectively protect equipment and maximize productivity, but also to protect food products from contamination in the event of lubricant exposure.
To further complicate the process, such facilities often include flame and heat sources in their operations, so fire resistance should be an additional requirement. Fortunately, some lubricant suppliers have developed advanced solutions that address all of the requirements for safe hydraulic lubrication in the food processing industry.
Fire-resistant fluid science uses the latest research and technology to make hydraulic fluids safer and more efficient, while maintaining their ability to perform as well as mineral oils. The fluids must continue to lubricate, to prevent rust, corrosion and oxidation, to dissipate heat, withstand pressure and temperature extremes, and have low-foaming tendencies. Recently developed hydraulic fluids offer all of those critical performance factors in addition to having a high flash point, contributing to fire resistance. Some are also biobased, making them more environmentally acceptable and a renewable resource.
Sophisticated research now has created high-performing fire-resistant fluids that are approved for use in the food processing industry, truly delivering the best of all worlds to food manufacturers who are concerned about safety, efficiency and performance.
The Right Choice
The following types of hydraulic fluids meet FM Global requirements for fire resistance and, when properly formulated, may be NSF registered for use in food processing operations:
1. Water glycols. These are water based fluids that contain a polyglycol thickener which provides viscosity, and propylene glycol which delivers low-temperature properties. These fluids also contain special additives for lubrication and liquid and vapor phase corrosion prevention.
2. Anhydrous fluids, or non-water-content products. These include fluids composed mainly of vegetable oil, making them biobased and a green renewable resource. These fluids also contain additives that increase lubrication, viscosity and antiwear properties, plus inhibitors that prevent rust, corrosion and oxidation.
Food manufacturers should choose the hydraulic fluid that best meets their fluid chemistry and other operational characteristics and priorities. Water glycol fluids are recommended by original equipment manufacturers based on their proven success at major food processing facilities. Facilities that currently use mineral oil based lubricants can be relatively easily converted to the vegetable oil based, environmentally acceptable anhydrous fluids.
Some fluid manufacturers carry extensive product lines of fire-resistant hydraulic fluids. One is Valley Forge, Pa.- headquartered Houghton International, which carries a full line of hydraulic fluids registered with both FM Global and NSF that are tailored to food processing operations. Its representatives work closely with manufacturers to select optimum fluid formulations, and provide technical service to support customers. This service includes product selection support, and analysis of in-service fluids to monitor their condition and performance.
The benefits of using fire-resistant H1 hydraulic fluids in food processing operations are clear:
Improved plant and worker safety.
H1 lubricants are required where theres the possibility of incidental food contact.
Protection of machinery from friction, corrosion, rust and oxidation.
Environmentally acceptable (anhydrous products).
Reduced insurance premiums.
Given the quality, price and performance of available food grade, fire-resistant hydraulic fluids, they should be adopted as best practice by food plant operators, to help make fires and contamination a thing of the past.