HYGIENE PRACTICES DURING MAINTENANCE OPERATIONS IN THE FOOD INDUSTRY
Recommended Hygiene Practices to Be Taken Before the Onset of Maintenance and Repair Operations
The following pre-service practices may create the necessary hygienic conditions allowing maintenance and repair without compromising the safety of the food produced with that equipment once production resumes (Jha, 2006; Smith and Keeler, 2007; NZFSA, 2009, 2010, Moerman et al., 2014):
- • A maintenance program must be available that includes procedures that describe how to do the work. Maintenance technicians can only perform their work in a hygienic manner, if they know exactly what is allowed and not allowed during their activities. Mishandling equipment during maintenance and repair, as well as poor lubrication practices, may compromise the safety and quality of the food produced. Therefore the following procedures must be integral parts of a documented maintenance program:
- — maintenance procedures;
- — lubrication procedures;
- — tool reconciliation procedures;
- — procedures for temporary repairs;
- — procedures for emergency repairs;
- — spare parts inventory program;
- — training procedures;
- — “hand-over” procedures;
- — audit procedures to verify that the work is being done properly.
These procedures should include a title, step-by-step actions to
complete the work, who is responsible for the work, how and where records shall be maintained, corrective actions to be carried out, and, finally, procedures for management to verify that the work was not only done, but done properly.
- • Some work such as drilling or welding will inevitably produce debris and dust. The area should be examined to assess the potential risk of contamination, and risk areas should be covered. A “Food Safety Maintenance/ repair Plan” should be developed and shared with affected employees prior to major construction or renovations.
- • Where necessary, traffic inside the food factory should be rerouted.
- • Whenever possible, maintenance should be done in a separate room outside the food processing area. As an example, fabrication and repair could occur in the maintenance workshop, but then care must be taken that there is sufficient access for machinery/equipment to be brought into the shop. Weld, thread or cut operations also can be done in any other area screened (isolated) from ingredient or packaging material storage and product handling.
- • Alternatively, when possible, production operators should remove food processing equipment from the processing room before repairs will be made, or the maintenance area must be segregated from production by use of tarps. No maintenance work shall be allowed during production if the necessary protection is not ensured.
- • Adequate screening is of paramount importance in exposed food areas, to prevent exposed food from becoming contaminated with metal shavings, filings and other airborne particles generated during maintenance and repair, and to protect it from grease removers, lubricants, paints, and paint odors.
- • An appropriate number of shields and plastic sheets must be available to contain possible contamination in the work area during on-line repairs.
- • The tarps or plastic sheeting (polyethylene or equivalent film) draped over adjacent equipment must be clean and free from dirt and water.
- • If it is necessary to stand on machinery, the equipment must be covered to prevent dirt and debris from contaminating the surface. If entry into process equipment is required, a plastic cover film must be laid down on the bottom of the process equipment.
- • Maintenance workers must necessarily use many tools in the production area. The maintenance tools of contractors should be company-owned. Where practical, maintenance tools should be dedicated to a specific area, because tools may be a source of L. monocytogenes, and other harmful microorganisms, as well as physical hazards (foreign bodies).
FIGURE 8.42 To improve hygiene and prevent cross-contamination, the production premises may be divided into visually separated zones, where each zone is assigned a specific color. In analogy with the color coding of cleaning tools, every zone can have its own colored set of maintenance tools and its own color-coded service equipment. Color coding is a tremendous tool because it works in all languages and makes these tools easily distinguishable from other production tools for better accountability. Courtesy of Carlisle Sanitary Maintenance Products.
No transfer of these hazards may occur from a less to a more hygienic area. By dividing the production premises into visually separated zones (Fig. 8.42) where each zone has its own colored set of maintenance tools and equipment, hygiene can be improved and cross-contamination can be eliminated. Also tool bags, tool boxes, receptacles, and trolleys may be provided with a color code. It is recommended that the color coding be the same as that implemented for cleaning equipment and cleaning tools.
- • Segregation of maintenance tools and equipment may result in the following categories: food contact versus nonfood contact, allergenic versus nonallergenic contact, wet versus dry, areas with basic/medium/high hygiene requirements, equipment versus nonequipment (e.g., repair of drains), halal versus nonhalal, kosher versus nonkosher, etc. Tools used in areas where foods are exposed should be exclusively used in these areas.
- • To avoid cross-contamination, workshops and storage areas for maintenance tools can also be designated to a specific zone. When each zone has its own workshop, the service crew must not cross less-hygienic areas. It is important to minimize the crossing of flows of people, goods, process equipment, cleaning tools, maintenance equipment, and maintenance tools. Floors as well as air currents may act as carriers of food pathogens, spoilage microorganisms, food debris (e.g., allergens), aerosols, etc. The fewer doors between different zones are opened, the better.
- • Color coding also may promote hygienic behavior among employees and help to ensure that they understand the maintenance plans of the company.
- • Broken parts of colored maintenance tools are visually more easy to detect if they become a foreign body in the product.
- • Tools used for repair and maintenance must not compromise the hygienic status of any product or packaging material. The maintenance tools must be free of rust, peeling paint and niches for bacteria (scratches, cracks, pockets, threads, etc.); and without wooden handles or knurling soft rubber grips. They should be noncorrosive, easy to inspect, clean, and disinfect, with smooth finish and hard plastic grips, and with fitted heads for equipment longevity. They must be designed in such a way that they can’t damage the process equipment (Fig. 8.43).
- • Maintenance tools and aids preferably should be designed with a minimum of parts. As an example, it is recommended that employees use one-piece ink pens made of metal, rather than plastic cap-and-pen types. This reduces the chance of a pen cap falling into product and ensures that the metal detector will find the entire pen.
- • Carbon steel tools with electroplated surface coating are available but have their limitations. The surface coating temporarily prevents the interaction of the free iron in the carbon steel tool with the oxygen in the environment, hence reducing the level of oxidation. However, because of intensive use and frequent cleaning/disinfection, the plating deteriorates
FIGURE 8.43 (A) The maintenance tools suffer from corrosion, are painted (paint may peel
off), contain niches and threads; have wooden handles or knurling soft rubber grips; or the tool heads may damage the stainless-steel surfaces of equipment and components. (B) These maintenance tools are made of stainless steel (noncorrosive), easy to inspect, clean, and disinfect, with smooth finish and hard plastic grips, and with fitted heads for equipment longevity. A system of color coding allows maintenance tools to be dedicated for use in specific zones, such as low, medium, or high hygiene areas. Courtesy of John Butts, Land O’Frost; courtesy of Steritool (Frank Moerman, © 2016).
with time, causing it to chip, flake, and peel. The tiny flakes and chips from the deteriorating chrome plating finally may become foreign matter in the food product. Furthermore, the exposed ferrous surface of the tool will transfer ferrous contaminants to the surface of a stainless-steel fastener or equipment, which subsequently will result in the formation of iron oxide, even at low levels of humidity. Moreover, bimetallic corrosion may occur. Therefore, stainless-steel maintenance tools suitable for intensive use and easy to clean and disinfect must be used. Stainless steel 316L, however, is not the ideal material of construction for maintenance tools, because it is not capable of achieving the hardness level required for high torque applications. As an example, the small serrations in the jaws of common slip joint pliers would likely wear too easily under normal use if they were manufactured from stainless steel 316L. Precipitation-hardened low carbon stainless steel 465 has proven to be excellent as a material of construction for maintenance tools due to its greater hardness, excellent tensile strength, and sufficient corrosion resistance over a long period of time. Maintenance tools with a long life reduce the need for replacement (Pekarsky, 2007).
- • In certain conditions the use of nonmetal tools is preferred over metal tools, especially if the latter can damage process equipment parts.
- • When maintenance or repair is performed at height, technicians need to use tools that are secured or tethered to prevent a hazard. Accidental dropping of tools while working at height can have devastating consequences. Smaller objects such as wrenches or sockets can cause severe injury to employees working beneath, while heavier tools such as a hammer can kill them. An injured employee may cost a food producer or maintenance contractor a lot of money: medical bills, workmen’s compensation claims, increasing safety insurance policies, potential lawsuits, bad publicity and reputation damage, workforce and labor unions discontent, strikes, etc. A wrench slipping out of a utility worker’s hand or a socket slipping out of a tool pouch also could cause damage to sensitive infrastructure (e.g., sensors) and equipment (e.g., damage to insulation, inside damage in a tall tank). A falling tool isn’t necessarily going to drop straight down, but often ricochets when hitting several objects on its way down to the ground. It thus can damage a multitude of components.
Reliable retention of tools to prevent them from falling when working at height not only may prevent employees from injury and death and protect equipment against damage, it also may reduce the possibility that tools get into product, and it provides accountability to prevent tool loss. Moreover, a built-in drop-prevention system reduces the chance that tools may be laid on food-contact surfaces or places prone to dirt build up, microbial contamination, etc.
Tools with built-in coils or other fastening devices are available allowing lanyard attachment. These lanyards can be attached to the operator’s wrist, belt, harness or other suitable tether site location, while ensuring that the original functionality and quality is maintained (Fig. 8.44). Tools weighing more than 2.5 kg should be attached by lanyard to the operator, more specifically by means of one lanyard hook attached and locked to an approved attachment point on the technician’s safety harness, belt, or wrist strap, and another lanyard hook attached and locked to the selected tool (Fig. 8.45). Tools weighing more than 5 kg should be attached by lanyard to a suitable fixed point.
FIGURE 8.44 Although the tool is secured, the lanyard gives technicians unrestricted tool use and doesn’t impede mobility or compromise personal safety equipment. Courtesy of Snap-on Industrial.
FIGURE 8.45 Means of attachment such as coils or other fastening devices are built into tools, and are not added as an accessory later. Courtesy of Snap-on Industrial.
- • Ordinary steel wool or steel brushes and scrapers should never be used on stainless steel surfaces, as particles of steel may get embedded in stainless-steel surfaces and rust.
- • Utensils such as knives, spoons, scoops, and ladles used for handling or measuring toxic chemicals and other nonfood materials should not be used for food contact.
- • Maintenance tools must be used with care so that they cannot be left in the production equipment. Use only the maintenance tools that are required for the job. The fewer tools that are taken in the area where servicing of the equipment must be done, the less chance that tools will get lost in the product stream or will be forgotten once the maintenance/ repair job is finished.
- • Maintenance tools must be stored off the floor, and in no way should service technicians pick up items from an uncovered floor. Furthermore, replacement equipment and parts must be kept at least 0.5 m away from walls to avoid pest infestation and breeding.
- • Maintenance tools must be inspected for broken parts. As soon as the slightest sign of deterioration is observed on a tool, the tool needs to be discarded and replaced with a new one.
- • Maintenance tools must be inspected for cleanliness. Where required, they must be recleaned. In all circumstances, it is essential to disinfect maintenance tools before entry in the food processing area. Use cleaners and disinfectants that are less harsh on these tools (less corrosive), while still being effective in the removal of food residues and dirt, and in the inactivation of food pathogens and spoilage microorganisms. Note that the maintenance tools must be thoroughly dried after cleaning.
- • Because maintenance staff are a foreign body risk, all unsecured objects (e.g., pens, pocket notebooks, small screwdrivers, pencils behind the ear, nonattached ear plugs, nuts and bolts in shirt pocket) which could fall into the product must be stored in the toolbox or the carrier used to bring parts to the work site.
- • Receptacles for maintenance tools should be marked in a clearly visible fashion, to show that they are “only used for maintenance operations.”
- • Tool bags and boxes, receptacles, and trolleys used by the maintenance staff and contractors should be assessed for their suitability for application in the intended environment (Fig. 8.46). Where necessary they should be cleaned and disinfected before being brought into processing and/or support areas. To do so, the tool bags and boxes should be made of a material that can be easily cleaned, e.g., not fabric. A documented cleaning and disinfection procedure must be implemented for that purpose.
- • Doing maintenance work and reparations over exposed product while standing on ladders and platforms is not allowed, because maintenance debris, nuts, bolts, screws, tape, lubricant, or any other dirt, as well as
FIGURE 8.46 Toolbox is suitable for use in this high hygienic area. Frank Moerman, © 2016.
maintenance tools, may fall onto production lines and into the food products beneath. During maintenance activities at height, production of exposed food products must be stopped. If open process equipment and lines used in the processing of exposed food can’t be moved aside, they must be protected by means of covers, and thoroughly cleaned and disinfected once maintenance and repairs are finished.
- • Stairs, ladders, scaffolds, platforms, pallet jacks (to move heavy equipment components), cherry pickers, etc. (for work at height) must be free of damage and corrosion, and clean. Where possible, they should be cleaned and disinfected.
- • Stairs, ladders, scaffolds, platforms, etc. must be made of impervious, noncorrodable, easy to clean and impact-resistant materials of construction. They must not have sharp corners and niches (scratches, cracks, pockets, threads, etc.) for bacteria to hide. Wooden planking as scaffold platform is not allowed. Work platforms must consist of steel plates (provided with a coating as protection against corrosion) containing a raised antislip material and preferably also kickplates (toeboard) over the whole perimeter of the walkway or platform. Open grating is not allowed. Stairs and ladders are often made of aluminum which has the advantage of being low in weight. Detergent and disinfectant solutions used to clean and disinfect stairs, ladders, etc. may not adversely affect the aluminum (must not induce corrosion).
- • Anything that moves within the plant (stairs, ladders, scaffolds, platforms, pallet jacks, cherry pickers, etc.) has to be controlled: use, location, etc.
- • Debris from engineering workshops (such as swarf and other unwanted materials) must be prevented from entering processing or support areas. This is especially important where engineering workshops have access ways (e.g., doorways) that lead into processing or support areas. This may be achieved by keeping doors closed, the use of swarf mats, boot washes, etc.