Unseen Threats On Your Plate: Physical Hazards

Physical hazards are foreign materials either intentionally or unintentionally introduced to food products (ex: metal fragments in ground meat) or naturally occurring objects (ex: bones in fish) that are hazardous to the consumer. A physical hazard can contaminate food products at any stage of production. Everyone in the food chain especially the food processors should take adequate measures to avoid physical hazards in food.

Physical Hazards Risk in Food

  • The extraneous matter that is not supposed to be there as part of your food, like rat droppings / undesirable ones like your hair
  • Hard or sharp objects are potential physical hazards and can cause: – cuts to the mouth or throat – damage to the intestines – damage to teeth or gums
  • The presence of physical hazards in food can trigger a food recall, affecting the brand name of your company and product.

Factors Determining a Potential Risk

Factors that cause potential risk to consumers in food products include:

  • Size: Health Canada states that anything in a food product, that is extraneous, and measures two millimetres or more in size can be a health risk.
  • Type of consumer: Products that target infants, the elderly, etc. have a higher risk level.
  • Type of product: The product’s form, such as infant formulas, beverages, etc., can increase risk levels.
  • Physical characteristics: The hardness, shape, and sharpness of a product can affect the risk level.

Common Physical Hazards

Common sources of physical hazards in food include:

Glass, paper pieces, hair, plastic, carton piece, nut, bolt, screw, metal pieces, pins, stem, fish bone, glove piece, wire tacks, equipment fragments, twigs, grass seed, shell, stone, buttons, jewellery, nails, tobacco pieces, steel scrub, paper pin, medicine strip, wooden piece, cap bottle, cling wrap, coins, watch, thread, sequences, temper glass and the list goes on.


                               Fig 01- Type of physical hazards

Prevention of Common Physical Hazards

  1. Glass: Protection for all the glass fixtures, if any, and numbering them.
  2. Paper piece: Visual inspection and proper sorting of all raw materials, have control of paper usage inside the processing unit.
  3. Hair: Proper usage of hair cap/Astro cap to cover hair properly, lint roller for clothes, and strict checkpoints at the entrance for food handlers and visitors must be maintained.
  4. Plastic: Limit the usage of plastic pouches and packages inside the processing area, train food handlers for proper waste disposal and the proper way to cut plastic pouches.
  5. Carton piece: Strictly prohibit the usage of carton boxes inside the processing area.
  6. Nut, Bolt, Screws, wire tacks, steel scrub, metal pieces & equipment Fragments: There must be controlled access to maintenance or engineering tools. These items need to be stored in a separate area under lock and key. Have numbering on the tools. Steel scrub usage for cleaning utensils should be avoided. Proper process of handling over once the maintenance is completed. Practice a system of passing all the processed finished goods under a metal detector to detect whether any metal pieces went into the product or not.
  7. Fishbone: Naturally occurs in fish. Proper sorting, cutting, and inspection must be followed.
  8. Glove piece: Visual inspection and training to food handlers regarding the usage and disposal of gloves should be given. Bright, preferably blue color gloves should be used for easy identification.
  9. Twigs: Proper sorting and visual inspection is required
  10. Grass seed, shell, stone: Proper sorting, sieving, and visual inspection of raw materials required
  11. Buttons, nails, coins, thread, sequences: Proper personal hygiene should be followed. Training and awareness to food handlers should be provided. Pockets filled with coins or notes shouldn’t be accepted or entertained inside the processing area. The dress code must be followed by workers, and visitors with loose buttons, sequence work on the dress, etc shouldn’t be allowed inside the processing area.
  12. Tobacco pieces: Strictly prohibit the usage of tobacco products by food handlers or visitors during their work hours and check for these during the entry checkpoint.
  13. Paper pin, medicine strip: The first aid box should be kept under lock and key under specific control. Nobody inside the food processing area should appreciate having any things in their pockets.
  14. Wooden piece: Have a wood policy. Wooden items should be avoided from the food processing area.
  15. Cap bottle, cling wrap: Need to have a separate area or specified location to keep and store packing materials. Make the food handlers train about waste disposal measures and storage methods.
  16. Watches and Jewellery: A Policy is required that restricts the usage
  17. Instruments & Equipment: Have a preventive and breakdown maintenance schedule and track it
  18. Spectacles: Needs to have control over it, only allow if it’s necessary, and can shift the food handler to low-risk areas. Coating-type and fiber-type glasses are also available.
  19. Clock, Windows, and camera lenses: Must have a protective coating to prevent the glass pieces from getting into food or food contact surfaces and have a numbering on it, to track the breakage history.
  20. Mobile glass, temper glass, wristwatch: Prohibit the usage of phones inside a food plant. If permitted, the food handler must have a specific designated place to keep their phone. Also, prohibit the use of wristwatches in the production area to avoid hazards.
  21. Dress: The source of glass pieces from the dress can be from the visitor whose dress has some glass decorations and sequin work. Untidy and rugged clothes must not be allowed in the processing area. There must be a visitor policy and strict checking by the authority that the visitors are adhering to the policy while entering a food plant. Can have a checkpoint at the entrance door for personal hygiene and the grooming part which includes the dress code too.

Recall Cases due to Physical Hazard:

DateBrand Name & Product NameCause for recall
11/20/2019Nabisco & Cheese NipsThe potential presence of plastic
11/15/2019Breakstone’s & Cottage CheeseThe potential presence of plastic and metal
09/06/2019Udi’s & Classic Hamburger BunsForeign Object White Plastic
08/01/2019Entenmann’s & Soft Baked Chocolate Chip CookiesDue to the potential presence of visible, blue plastic pieces
07/11/2019Ragu & Pasta SaucePotential contamination with plastic fragments
07/10/2019Multiple brands & Hamburger and Hot Dog BunsPotential Presence of Small Pieces of Hard Plastic
02/11/2019WTRMLN WTR & Cold press juiced WatermelonPossible Presence of Soft Plastic Pieces
11/15/2019Breakstone’s & Cottage CheeseThe potential presence of plastic and metal
06/21/2019Parent’s Choice & Advantage Infant Formula Milk-Based Powder with IronThe potential presence of metal foreign material
07/18/2018H-E-B & Creamy Creations ice creams and sherbetsDue to broken metal in processing equipment
05/30/2018EconoMax, Hill Country Fare, Creamy Creations & Ice Cream and sherbetForeign material-metal
02/08/2018Grreat & Grreat Choice Adult Dog Food with Chicken and Ricemetal contamination that could potentially be a choking hazard to pets
02/08/2018Bright Farms & Salad GreensPotential Presence of Metal Pieces from Construction
02/09/2018Trident & Frozen Multi-grain Alaskan CodContains small pieces of plastic.
12/29/2017Casa Sanchez & GuacamoleForeign matter: a small piece of yellow plastic
12/29/2017Fit & Active & Chocolatey Chip Protein Meal BarsDue to the Presence of Plastic Piece
10/13/2017Merkts & Port Wine Cheese SpreadPresence of small pieces of plastic

Recall Cases:

  1. Processed meat, Tyson Foods chicken tenders, Jimmy Dean sausages and Spam recalls rise dramatically as consumers bite down on metal, plastic and glass. Metal parts are breaking off machines that mix, chop and puree ingredients. Plant workers’ rubber gloves are falling into the meat mixes. And bits of plastic and glass from meat packaging and ingredient containers are getting ground into the food.

                          Fig02: Physical hazards found in Jimmy Dean sausages        

    2. On 20.11.2019 in USA, NABISCO RECALLS 11-OUNCE BOXES OF CHEESE NIPS OVER PLASTIC CONTAMINATON. The recall notice states, noting the pieces came from a dough scraper that was incorporated into the production process of a small amount of product.”

    3. On 20.11.2019 in USA, Kraft Heinz recalls Breakstone’s cottage cheese for metal, and plastic bits, no reports of illness or injury related to the issue. 

    4. On Nov 6, 2019 in USA, Chicken recall: More than 2 million pounds recalled, may be contaminated with metal.

    5. Mom finds nail in school canteen lunch; complaint with Dubai Municipality, KHDA. A parent of a four-year-old schoolgirl was terribly shocked when he found a nail in his child’s unfinished school lunch box. She found a rusted nail stuck in the dosa batter.     


                                 Fig 03: Nail found in school canteen lunch

6. On 15.05.2017, UK, A person damages two front teeth after biting into a takeaway pizza ‘with 5p coin baked into the dough’.    


                                      Fig 04: 5p coin found in takeaway pizza

7. On, 17 Sep 2018 in Singapore, Strawberry needle scare: Growers to look to metal detectors to contain contamination crisis,

8. Bingo (Tedhe Medhe) — thread found in bingo (tedhe medhe). A person was having bingo (Tedhe medhe) and found a long piece of thread in it on Aug 25, 2019.                                        

                                                                                                                       Fig 05: Long piece of thread in Bingo (Tedhe Medhe)         

9. McDonald’s, at Choo Yun Ting on FEB 9, 2019 received two customer complaints. One a piece of paper in his scrambled eggs. Another complaint was a piece of plastic embedded inside (the) fish patty.


     Fig 06: A piece of plastic & Paper found in fish patty & v scrambled eggs respectively     

10. Australian Woman Nearly Breaks Tooth after Biting into Metal Rod Inside McDonald’s Burger. A woman in Australia’s Sydney had a harrowing experience when she went to have a meal at McDonald’s. Ada Teaupa found a small metal rod in her chicken and cheeseburger that she ordered from the popular fast-food chain on FEBRUARY 18, 2020.                   

                            Fig 07: Metal Rod found Inside McDonald’s Burger

11. A Pregnant lady got a cigarette butt in her Krispy Kreme doughnut on 11 May 2015, in Australia.


                                           Fig 08: Cigarette butt found inside doughnut

12. Cigarette found in food dish 2PL – Picture of Mehak Grill House, Ilford. Dish did not taste right and then I found a black cigarette with a very strong tobacco smell. Then found the filter of the cigarette amongst the chow Mein at Alisonhauxwell, UK December 18, 2016.


                                         Fig 09: Cigarette filter found in chow Mein

        13. Man discovers half-smoked cigarette in Chinese takeaway, Horndean, Hampshire, UK on 18 Feb 2018


                                  Fig 10: Half-smoked cigarette in Chinese takeaway

       14. On 22 August 2019, Japan, A 73 years old man, needed part of his bowel removed after a 2cm-long fish bone he accidentally swallowed perforated his intestine.      


                                  Fig 11: Perforated his intestine due to fish bone

 15. On 03/11/2011, McDonald’s Chicken nuggets found with bone inside. McDonalds says on their website their chicken McNuggets are boneless.       


                Fig 12: McDonald’s boneless Chicken nuggets found with bone inside

16. Unhappy meal: Six-year-old bites into chicken McNuggets and ‘finds half-inch piece of BONE’. She took a bite out of the nugget and chipped her tooth. Mr Merry claims that he then spotted a bone inside the piece of chicken on 14.03.2014.

17. A nut bolt was found inside a donut purchased from one of their outlets in Bangalore, India in the year 2022.


                                   Fig 13: A nut bolt inside a donut from MOD                

Detecting and Eliminating Physical Hazards

There are several methods available to detect foreign bodies on food processing production lines:

  • Putting processes and controls in terms of PRPs
  • Magnets can be used to attract and remove metal from products.
  • Metal detectors can detect metal in food and should be set up to reject products if a metal is detected. Equipment should be properly maintained to ensure it is always accurate and doesn’t produce false positives.
  • X-ray machines can be used to identify hazards such as stones, bones and hard plastics, as well as metal.
  • Food radar systems transmit low-power microwaves through food products to identify foreign bodies such as metals, plastics, bones or kernels in food.

Physical hazards are dangerous, both for the consumers as well as for the company. They can be detrimental to the brand name and can leave a huge burn in the company’s pockets. The food manufacturers should have control over foreign particles getting into the product in terms of infrastructure, man, method, and handling practices. The food handlers must be aware and trained regarding the reason and consequences of physical hazards in food.

There should be proper monitoring checks ( such checks can be established by implementing HACCP standards . Read more here. ) in place for raw materials, production line, and dispatch line, and verified as well to avoid contamination. The trained and certified officials to handle the production, QA section etc. can help too. Proper traceability shall be carried out if an emergency happens. All food handlers, people inside out and top management need to strive for the safety and quality of food. After all, “Prevention is Better than Cure”.

We, at Food Safety Works, can help you identify the gaps in your systems and, of course, also how to fix them effectively.



About the Author

         Mythri R is an Associate Consultant at Food Safety Works. She has been working with a lot of food processing units to ensure they have a robust Food Safety Management System. She is very well conversant with HACCP and ISO22000.

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