What are Physical Hazards?

Physical hazards consist of any extraneous foreign substance in food. They can be present in the final product due to contaminated raw materials, poorly designed or poorly maintained equipment and facilities, improper hygiene practices, and poor implementation or failure to observe proper standard operating procedures. Physical hazards can cause damage to teeth and lacerations to the mouth, tongue, throat, stomach, and intestine. They may otherwise be aesthetically unpleasant.

What Are Aesthetically Unpleasant Substances?

Aesthetically unpleasant substances may include small insects, insect parts, rodent hair, human hair, and filth. These are likely to cause “mental anguish” but not any physical injury. Substances likely to cause physical injury include stones, glass, and metal. The FDA has established guidelines for the acceptable length of hard or sharp substances in food in its Compliance Policy Guide (CPG) Sec 555.425 on “Foods-Adulteration involving hard or sharp foreign objects”. According to the guide, ready-to-eat or minimally processed foods are subject to seizure or import detention if they contain hard or sharp objects having a length of 7 mm to 25 mm.

Hard or sharp substances that are natural components of food such as bones in seafood and shells in nuts are not subject to the above rule since customers are generally aware that they may be present and therefore look out for them. However, products with labels indicating that the substance has been removed are of greater concern. For example, if the label says “boneless fish” or “pitted olives”, consumers will not be expecting the presence of the removed substance and will therefore be at risk of injury. The presence of bones and pits exceeding the FDA’s established “defect action level” would render the product “adulterated”.

Prerequisite Programs Control

Physical hazards can be controlled in several of your prerequisite programs as well as in your HACCP plan. Examples of prerequisite programs where they can be controlled include supplier control, equipment, facility, cleaning and sanitation, and personal hygiene.

Supplier

Purchase your raw materials only from approved suppliers. Inspect raw materials upon receipt and store them separately from finished or partially processed materials. You can request letters of guarantee from suppliers to provide assurance that your raw materials are free from or within the limits of acceptable physical hazards. Request certificates of analysis as appropriate to confirm that concentrations of foreign materials such as insect parts and other non-food materials in the shipment are within acceptable limits.

Equipment

Install, maintain and calibrate appropriate equipment for sorting and cleaning raw materials and packaging. These may include flumes, water sprayers, bottle washers, color graders, sieves, and aspirators. Check their settings at the start and end of the operation and at established frequencies throughout production to make sure that they are working properly. Equipment involving metal-to-metal contact or those that contain parts that can break or become loose should be visually inspected at appropriate frequencies and after jams, to check for metal shavings, missing parts, or breaks.

Facility

Design your facility to allow for proper cleaning and maintenance, and prevention of cross-contamination. For example, your walls should be smooth, cleanable, and free from peeling paint or chipping surface. Overhead structures should be free from cobwebs, rust, dust, and any material that could fall into the food. Uncovered lighting may break and contaminate food, so make sure that they are covered with a shatterproof shield. Physical barriers should be installed at entrances such as doors, strip curtains, and air curtains to prevent the entry of pests, dust, and movement of other physical hazards from raw material handling areas into areas where food is being processed.

Cleaning and Sanitation

Follow your sanitation standard operating procedures (SSOP) to ensure that your equipment and facility are properly cleaned and sanitized before processing. This will confirm that there is no physical residue to be transferred to the product during processing. If equipment maintenance is done prior to operating equipment, ensure that all tools and loose hardware are removed from the area. Negligence in this duty can result in significant damage to expensive equipment.

Personal Hygiene

Train your employees in the practice of good personal hygiene, including proper hand washing and wearing personal protective gear. Remember that no jewelry, including tongue rings should be worn in the facility. Wedding bands may be allowed but they must be plain and should be covered with a glove when handling food. Bandaids used should be brightly colored so that they can be easily detected if they fall off. Do not allow any meal, drink, or snack to be brought into the processing or changing areas. Instead, provide your employees a designated area in the facility for eating and drinking.

HACCP Control

HACCP control of physical hazards may take the form of visual inspection or instrumentation. Two common hazards that are controlled in the HACCP plan are glass and metal. The presence of glass on or near the equipment or in containers can be inspected visually by examination of the cleaning and inversion of empty glass containers; examination of empty glass containers; or examination of filled glass containers. Check pallets and cases of empty jars for damage and broken jars. Also check glass cleaning equipment, glass filling and capping equipment, glass conveyors, and surrounding floors for broken glass. The visual checks should be done by properly trained inspection personnel at the start of each day, continuously throughout the operation, at the end of each operation, and whenever there is an equipment malfunction that could increase the likelihood of breakage.

X-ray detection may be used to detect and remove food and packages containing glass fragments. The appropriate inspection personnel should check the machine at least once daily to verify that it is working properly. Whenever you detect glass fragments, stop the operation and remove the fragments from the equipment and surrounding area. The source of the fragments should be located, and adjustments made to prevent breakage in the future. Products containing glass should be destroyed, reworked to remove the fragments, or diverted to non-food use. If the product did not pass through a properly functioning x-ray machine, hold it until it can be examined by the x-ray machine.

Metal fragments may also be monitored and controlled by visual inspection and instrumentation using a metal detector. Visual inspections should be done at the start, end, and throughout the operation, as well as when jams are encountered. During visual inspections, the operator should look for signs of equipment damage or missing parts. If damage or missing parts is observed, the operator should stop the line, adjust the equipment, and hold all products since the last acceptable visual check.

No product should be released until they pass a metal detector check. Destroy rejected products, or you may rework or divert them for non-food use. To ensure proper working of your metal detector, challenge the machine with standard sensitivity test wands before start-up, periodically throughout the operation, and whenever there are any changes in processing factors.