Part 1: Basic Requirements and Considerations
Engineering/Construction Requirements to Avoid Food Processing Contamination During Construction
Completing a construction project at an operating food processing plant is a complicated and detailed task. The process involves activities above and beyond those generally associated with construction projects at non-food industrial plants. To ensure success without contamination, both the plant operator and the selected engineer/constructor must understand and implement Current Good Manufacturing Practice, Hazard Analysis and Risk-Based Preventive Controls for Human Food (21 CFR Part 117). This series describes the key factors that ensure successful completion of a construction project at an operating food processing plant.
Engineering/Construction of additions or modifications including lessons learned
As with any industrial construction project at an operating plant, the engineering for an addition or modification to a food processing plant starts with a conceptual design followed by:
- The physical layout of mechanical and electrical systems
- Equipment selection and sizing
- Structure and foundation design
- Creation of construction drawings
- Construction activities planning so that the plant operation is not disrupted
- Safety planning for new design as it relates to personnel
In the food industry, there is another layer of activities dictated by the food process itself that goes far beyond customary OSHA and journeyman training. These activities are required to ensure that construction does not contaminate the food and involves the preparation and implementation of food safety training, safety checklists, specialized construction procedures, and audit procedures.
Part 2: Training Contractors
Ideally, plant managers and operators should select contractors and maintenance personnel for the project with prior food industry experience, preferably with Food Safety Preventive Controls Alliance (FSPCA)-qualified individuals, Safe Quality Food Institute (SQFI) training, or equivalent. However, this not always possible. Therefore, workers new to the food industry must be given general food industry orientation training. Both experienced and new workers must receive training that is site-specific, because no two food processing plants, even within the same industry working with the same product, are identical. If the plant has its own written contractor work rules, they should be included in the site-specific training.
Training, Programs, and Requirements
A Hazard Analysis and Risk-Based Preventive Controls (HARPC) program compliant with 21 CFR 117, Subpart C must be developed for each project site and personnel must be trained in it. Thus, a food plant must validate the HARPC plan and all project personnel must be trained in HARPC interpretation, and how it will be implemented at the site.
This training should be conducted by personnel from the food plant or the engineering firm who are FSPCA Preventive Controls Qualified Individuals (PCQI) or SQF-certified practitioners. Managers should provide written training materials to all trainees. Documented competency testing should be administered. Project stakeholders should consider a FSPCA- or SQFI-certified third-party training body for these tasks.
This training is not a onetime effort but should be reinforced with weekly toolbox talks and food safety refreshers. Disciplinary methods must be implemented for deliberate violation of safety rules.
Fundamental to all food safety plans are the Current Good Manufacturing Practices (Cgmp) as laid out in 21 CFR 117 and other prerequisite programs, such as hygienic zoning, product specifications, or other plant-specific protocols. While these programs are intended primarily for food processing plant operators, the principles apply to construction activities in operating plants.
Contractors should be trained in the pertinent sections of 21 CFR 117 that deal with food contamination from the following sources:
- Grinding/Welding debris
- Foot traffic
- General construction debris
- Cutting oils
- Debris shaken loose from construction activities
- Drain Backups
- Cross contamination from tools and equipment used at multiple facilities
Part 3: Pre-Project Preparation
With the best intentions in the world, construction workers will not remember all the steps required to work safely in an operating food processing plant no more than the pilot of a 747 can remember all the steps required to take-off or land safely. The pilot uses a checklist – not because he’s incompetent – but to guarantee his passengers’ safety. Likewise, the construction crews in an operating food processing plant use checklists to ensure the safety of the consumers of the food produced in the plant. Some of the checklists used are:
- Pre-Construction Walk-Through Checklist
- Audit Checklist during Consruction
- Start Up Safety Checklist
- Walk Through Checklist
Pre-Planning of Work
In a typical non-food industrial plant, pre-planning the work for a modification or addition involves ensuring that the construction does not interfere with plant operation and materials and equipment can be brought into the plant and stored until needed. All these steps are required for a food processing plant, but in addition food safety measures must be added. The following additional steps are needed in an operating food processing plant:
- Develop a Food Safety Plan with HARPC
- Develop Safe Plans of Action to avoid food contamination
- Use Lessons Learned from previous work experience to plan work
Part 4: Identifying Protection Areas
Level Identification of Protection by Plant Area
Each area of the operating food processing plant in which construction is planned has unique protection requirements. These must be identified and included in the construction plan and included as Critical Control Points in the Food Safety Plan.
The first step is for plant management to identify the plant areas by activity and the protection required. They may perform this step themselves or with the engineer/constructor. Address the following areas:
- Raw Goods and Ingredients – Grains
- Raw Goods and Ingredients – Meats
- Raw Goods and Ingredients – Fats, Oils and Other Liquids
- Wet Processing
- Dry Processing
- Building Exterior and Grounds
Part 5: Enclosures and Hygienic Segregation
Enclosures and Hygienic Segregation
Enclosures are used to keep things out and/or to keep things in. Enclosures keep construction contamination out of the food processing areas and keep food processing materials out of the construction area; keep contractors, material and equipment in the construction area and control traffic between the two areas. The following types of enclosures may be used depending on the area and level of protection required:
- Stud Walls w/plastic sheeting 1 side
- Stud Walls w/plastic sheeting both sides
- Stud Walls w/Masonite sheeting & plastic
- Sloped roofs (if required) on containment area to allow water, food debris and dust particles to run off the containment
HVAC Systems and Differential Pressures
Keeping construction contamination out of the food processing area requires that construction contamination be contained within the construction area. This is achieved by maintaining a negative pressure in the construction area thus air flow is into the construction area, rather than construction area air and contaminants flowing into production areas. A well-designed HVAC system is vital to ensure the effectiveness of enclosures and hygienic separation. The amount of negative air pressure is dependent on the area’s classification.
For normal areas, the capture velocity may be about 100 feet per minute. In high-hazard or dusty areas, the capture velocity may be as high as 150 to 200 feet per minute. Six air changes per hour should be considered the minimum ventilation required inside the containment area and may be as high as 10 to 15 in high-hazard areas.
Pay special attention to the location of the HVAC system exhaust. If the air cannot be exhausted to a safe location outside, the use of properly sized HEPA filters is an alternate. Exhausts discharging outdoors should be located at least 10 feet above and 25 feet away from any air intakes. Exhaust fans should be located so that only the vacuum side of the fan is inside the enclosure. Ideally, exhausts should be straight up to allow the plume to be carried from the plant. Condensation control inside and outside the containment walls and worker comfort must also be included in the HVAC system design.
Entrances and Exits
Carefully consider how to protect the areas when contractors are not present. One method is the provision of field-constructed windows in the containment tarps or walls to allow plant personnel to see into construction areas without entering the construction area.
There may be plant personnel, equipment and material movement around the protected areas and there may be contractor personnel, equipment and material movement into and out of the protected areas. Establish Critical Control Points for these movements.
Transition zones, such as airlocks, may be needed to provide isolation between the construction area and the protected area to permit these movements and to accommodate contractor check in areas. Swabbing and testing locations must be established.
Removing Waste Materials
There are usually waste materials associated with construction projects from demolition work or construction activities. Provisions must be in place for handling such materials and removing them from and possibly through the protected area. All such waste should be considered contaminated and be tested to determine how it should be handled.
The integrity of the enclosure/containment must be monitored on at least a daily basis and any damage or breaches repaired immediately. Any breaches should also be documented and reported both to plant supervision and to the engineer/contractor project manager. The cause for the breach must be established and eliminated where possible. It could be that a plant operator needs to get into the segregation every day in order to operate equipment or valves. If that is the case, the enclosure/segregation should be modified if possible to prevent such breaches.
Section 6: In and out of the Hygienic area
Sanitizing Personnel, Equipment and Materials
When contractors must enter or pass through a food protected area to access the construction area they must take the following precautions:
- All personal equipment (tools) must be sanitized prior to entering plant and prior to removal from work area
- Bring in only tools needed for the job – don’t bring in tool boxes
- Sanitize the tools – use tool wash sinks, sanitizing wipes, captive tool program
- Document tool cleaning
- Swab and test tools as needed
- Sanitize heavy equipment, carts, dollies or rolling stock
Associated Fumes and Odors from Traffic, Tools and Materials
Vehicles, tools and materials used in construction can produce fumes and odors that can contaminate food and cause illness in workers. The following measures must be taken to prevent such fumes and odors from contaminating food or causing worker illness.
- Ventilate to the outdoors (away from any plant air intakes) for vehicles going to/from construction areas.
- Consider using only propane-fired or electric vehicles inside the building.
- When vehicles are used inside containment, continuously monitor carbon monoxide to prevent worker illness.
- Adequately ventilate for paints, caulks, solvents, epoxies and other coatings that generate vapors that can overwhelm workers and taint food on nearby production lines.
- Adequately ventilate welding fumes that produce vapors and particulates that can overwhelm workers and taint food – electrostatic precipitators can help filter particulates and carbon filters can help remove odors.
- Ensure the HVAC is designed to prevent pockets of fumes or gases from collecting in spaces that could overcome workers
- Control exhausts and any vaporized operating oil from air tools that can carry contaminants.
Critical Control Points should be established along the designated materials path.
During construction materials and equipment will be moving in and out of the plant constantly. In order to control contamination, a designated route must be developed from the plant entry point to the construction area. This route must be reviewed and approved by plant operations and maintained and sanitized by the plant or tradesmen. Any open food streams along the route must be protected. This may require additional hand/foot/equipment/material sanitizing requirements and sanitizing locations.
If soils must be transported through the plant, covers must be used on buggies and the wheels must be sanitized when leaving the construction area. Material spotters who move in front of the loads should be used to guide the loads through the plant.
The planned designated route for materials through the plant must be assessed on an ongoing basis because conditions in the plant may change. The plan should be documented and be posted in the contractor work areas. Assessments of the plan should also be documented. And finally, the route should be marked throughout the plant and this marking must be updated depending on the results of the ongoing plant assessments.
Fabrication materials and equipment constantly arrive at the plant during construction and need to be stored prior to being used. To minimize on site storage requirements, Just in Time (JIT) inventory methods should be used when possible. Materials may be stored outside or inside depending on the nature and size of the items.
Section 7: Fabrication and Laydown
Fabrication & Lay-down
Smaller fabrication items should be stored indoors unless there is no lay-down area available. In this case, they could be stored in tractor trailers.
Inside storage areas should be:
- Tarped or designated with temporary barricades
- Monitored for accumulation of food dusts/debris
- Cleaned and sanitized as necessary
- Scheduled for inspection by sanitation
- Lit by temporary lighting as required
- Provided with plastic cribbing to store items for sanitation purposes
In the fabrication area, the following procedures should be followed and the responsibility established for whom is conducting the inspections to maintain a food personnel safe environment.
- – Area tarped to contain debris generated by fabrication activities
- – Area monitored for accumulation of food dusts/debris
- – Area cleaned and sanitized as necessary
- – Area scheduled for inspection by sanitation
- – Temporary lighting installed as required
- – Items staged on plastic cribbing for sanitation purposes
- – Welding barricades/shades usage.
- – Temporary ventilation and/or electrostatic precipitators as required to eliminate fumes from welding or painting
- Inspect arriving equipment for possible infestation
- Sanitize new equipment coming into the plant
- Plan for an equipment sanitizing and drying area
- Removal of all wood cribbing, spacers, and chocks prior to bringing new equipment into the plant
- Document sanitizing
Section 8: Clean-up to Start-up
Clean-up Prior to Start-up
When the construction has been completed, the contractor’s job is not done. There is still much to be done to render the construction area fit for food processing. This goes far beyond the normal post construction industrial project clean-up. It starts with the normal contractor broom, brush and mop clean-up of the construction area.
All equipment that was worked on during the construction must be tagged and the tagging must be documented. The tagged equipment must be sanitized, swabbed, tested and, if necessary, re-sanitized.
The segregation enclosure walls must be sanitized prior to removal and decisions made as to whether the components such as metal studs and other non-porous materials can be re-used.
Special sanitizing methods must be used for non-wash down equipment such as electrical devices and switchgear. Alcohol based sanitary wipes can be used for the electrical equipment. Sanitizing of other equipment may require superheated steam or dry ice.
Testing in Production Areas – Swabs, Number of Tests
After the clean-up has been completed, the production areas must be tested to ensure that they are ready for production. A 3D grid for the production area should be established and testing locations specified. Swab locations should include the traffic paths and the main entrances and exits from the construction area. The number
of swabs to be taken from an area should have been defined prior to the start of the project. Food and air samples must be taken and non-food contact surfaces must be tested.
If, during this testing process, an area is judged to be contaminated and is re-sanitized it must be re-tested. It is critical that the number of tests required before an area is deemed suitable for production be established by the plant food safety department.
Part 9: Consideration in Hiring
What to Seek in an Engineer/Contractor for Food Processing Plant Construction and/or Modification Projects
The key factor to consider when selecting an engineer/contractor is previous experience in the food industry, ideally in the type of plant under consideration.
Other factors that should be considered are:
- Principals or top management with food industry backgrounds
- Long-term clients in the food industry
- Testimonials from satisfied clients
- Integrated team consisting of engineers and constructors under the same management to minimize hand-offs and communication problems
- Team qualifications – food industry background preferred
- HACCP certification – what percentage of the team is HACCP certified?
- Sufficient number of SQF practitioners or PCQI on staff to cover all projects
- How the engineer/constructor works with the plant – is it an “us and them”-type relationship or “we”?
- Contractor Hiring criteria – food industry experience is more important than training
- Project managers to monitor food safety regulatory (FDA or USDA) requirements to ensure compliance
- Training of contractors in cGMP for Human Food