Foreign Matter | American Society of Baking
Food Safety:

Foreign Matter

What is foreign matter?

Foreign matter is defined as any kind of outside contaminant introduced to a food product at any point in its production or distribution. Problems with foreign matter may arise from equipment design flaws, structural issues, or employee handling.1

Glass is the most commonly reported foreign material in food that can cause consumer injury.2

The amount of foreign matter can affect the risk it creates for the consumer. A foreign matter control program can help a food processing facility control conditions that pose risks of product contamination.

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Relevance and regulation

The FDA notes that hard or sharp particles that are natural parts of food, such as bones in seafood or the shells of nuts, do not usually cause injury because the consumer is aware of them. One exception is when a food is labeled as having had the hard component removed, such as pitted cherries.

If a food product contains a hard or sharp foreign object that is 7–25 mm long, and the product is considered ready-to-eat, or has minimal preparation steps that would not eliminate or neutralize the hazard of the foreign object, then the product should be considered adulterated.3


Each food facility should create and establish a foreign matter control program that suits its particular needs. Therefore, not all control programs will look the same, though they should all include a few main components:1

1. Use of detection devices

These devices remove or limit the amount of foreign matter in a food product, which may include magnets, sifters, filters, strainers, metal detectors, X-rays, and destoner units.

2. Follow-up on findings

If foreign matter is discovered in a product, it should not only be removed or neutralized, but also investigated. Identify the source of the contamination and resolve the issue that caused it.

3. Monitoring of trends

Foreign matter and relevant investigations of it should be documented and reviewed periodically to look for possible trends associated with incidents.

4. Education and training

Employees should be educated on the importance of the control program. Those employees who are responsible for monitoring a foreign material device should receive proper training. These training programs should occur at least once a year and should include a review of each device, the procedures it is involved in, proper documentation, and what to do in case of foreign matter detection.


  1. AIB International. “Chapter 6: Foreign Matter Program.” The AIB GMP and Prerequisite Guide.
  2.  Wilm, K.H. “Foreign Object Detection: Integration in Food Production.” Food Safety Magazine. Oct./Nov. 2012.
  3.  U.S. Food and Drug Administration. Compliance Policy Guide. Sec. 555.425. May 2005.