Mixtures are best when shaken... or stirred...
All About Mixtures
Food contact materials and articles often contain more than one component. These components can range from discrete chemicals to complex polymeric substances, and each component carries its own set of Food Type and Condition of Use Limitations (or absence thereof). Provided that each individual component otherwise has a suitable US Food and Drug Administration (FDA) status, we can apply two simple rules to determine what limitations apply to the finished product composed of these individual components:
- If the individual components are physically blended together, such that no chemical reaction occurs, the Food Types and Conditions of Use for the finished product are the most stringent of any one of the individual components.1
- If the individual components are chemically reacted together, such that a new substance is formed, then the Food Types and Conditions of Use for the finished substance must be evaluated on a case-by-case basis.
Examples of How Mixtures are Evaluated
Here are some (hopefully!) easy to follow examples:
Physical Blends | Conditions of Use:
A new product is manufactured from a physical blend of Component A2 and Component B. Component A is authorized for use under Conditions of Use A-H, and Component B is authorized for use under Conditions of Use E-G. The finished product is, therefore, authorized for use under Condition of Use E-G (only).
Chemical Reactions | Conditions of Use:
A new product is manufactured from a chemical reaction of Component A and Component B. Component A is authorized for use under Conditions of Use A-H, and Component B is authorized for use under Conditions of Use E-G. The Conditions of Use for the finished product will need to be independently assessed.
Physical Blends | Food Types:
A new product is manufactured from a physical blend of Component A and Component B. Component A is authorized for use in contact with Food Types I, II and III, and Component B is authorized for use in contact with Food Types II, III and VI. The finished product is, therefore, authorized for use in contact with Food Types II and III (only).
Chemical Reactions | Food Types:
A new product is manufactured from a physical blend of Component A and Component B. Component A is authorized for use in contact with Food Types I, II and III, and Component B is authorized for use in contact with Food Types II, III and VI. The finished product will need to be independently assessed to determine which types of food it may contact.
The same principles apply where individual components contain a combination of both Food Type and Condition of Use restrictions:
Physical Blends | Food Types and Conditions of Use:
A new product is manufactured from a physical blend of Component A and Component B. Component A is authorized for use in contact with Food Types I, II and III under Conditions of Use A-H, and Component B is authorized for use in contact with Food Types II, III and VI under Conditions of Use E-G. The finished product is, therefore, authorized for use in contact with Food Types II and III under Conditions of Use E-G (only).
Chemical Reactions | Food Types and Conditions of Use:
A new product is manufactured from a physical blend of Component A and Component B. Component A is authorized for use in contact with Food Types I, II and III under Conditions of Use A-H, and Component B is authorized for use in contact with Food Types II, III and VI under Conditions of Use E-G. The finished product will need to be independently assessed to determine appropriate Food Types and Conditions of Use.
The Importance of Good Advice
When a chemical reaction occurs, such that Component A + Component B create Component C, an independent assessment to determine Food Types and Conditions of Use may take a number of factors into consideration, including (among others): (1) the use level of the substance; (2) the resulting level of migration of, or exposure to the substance in the diet; (3) the safety and toxicology profile of Component C (which may be based, in part, on the safety profile of Components A and B at sufficiently low levels of migration and exposure); and (4) the intended use of the finished food-contact material or article.
These types of evaluations range from simple to complex, and the inadvertent introduction of a substance that contains (and therefore results in) unintended Food Type or Condition of Use limitations could have a significant impact on the suitable regulatory status and marketability of the finished food-contact material or article. Therefore, to ensure both an accurate regulatory assessment – and happy downstream customers – it is strongly recommended that companies obtain advice from counsel well-versed in these types of evaluations where mixtures are involved.
Footnotes
1. Any extractive limitations, if applicable, continue to apply to each of the physical blend's individual components.
2. Note that "Component A" could itself be a physical mixture (or chemical reaction) where the appropriate Food Type and Condition of Use limitations have previously been determined.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.