FDA 21 CFR 177.1660 Tetramethylene Terephthalate

The standard “FDA 21 CFR 177.1660 Tetramethylene terephthalate” published by the U.S. Food and Drug Administration (FDA) under the Code of Federal Regulations (CFR) describes a procedure for the safe use of poly(tetramethylene terephthalate) (poly(oxytetramethyleneoxyter-ephthaloyl)) as substances or components of substances intended to come into contact with food in accordance with the prescribed conditions.

For the purpose of this standard, poly(tetramethylene terephthalate) is the reaction product of dimethyl terephthalate with 1,4-butanediol and some optional substances may be added to impart the desired technological properties to the polymer.

Poly(tetramethylene terephthalate) as defined in this standard is optional helper (adjuvant) substances. The quantity of any optional excipient used in the production of the polymer does not exceed the amount reasonably necessary to achieve the intended technical or physical effect. Such excipients may include substances generally recognized as safe in foods, substances used in accordance with previous approval, and substances permitted under applicable regulations in this section.

The inherent viscosity of a 0,50 percent solution of the polymer in phenol/tetrachloroethane (60/40 ratio by weight) solvent is not less than 0,6, as determined using a Wagner viscometer or equivalent and calculated from the equation given in the standard.

Poly(tetramethylene terephthalate) in finished form intended for food contact gives total extractives as follows:

• It should not exceed 0,08 milligrams per square inch of food contact surface when extracted with distilled water at 121 degrees for 2 hours.
• Not to exceed 0,02 milligrams per square inch of food contact surface when extracted with n-heptane for 2 hours at 66 degrees.
• Not to exceed 0,04 milligrams per square inch of food contact surface when extracted with 3 percent aqueous acetic acid at 100 degrees for 2 hours.
• Not to exceed 0,02 milligrams per square inch of food contact surface when extracted with 50 percent ethanol for 2 hours at 66 degrees.

FDA standard 21 CFR 177.1660 covers polyurethane resins used as components of articles intended for repeated use in food contact. The purpose of this standard is to determine which polyurethane resins can be safely used in coatings, adhesives, or food contact products such as utensils, conveyor belts, or gaskets.

Polyurethane resins include:

• Allowed reactants (such as polyols and diisocyanates)
• Specific additives and their restrictions
• Limitations on residual monomers and extractables

The basic requirement is that the resins used must be in repeated contact with food and must not transfer unsafe substances into the food (i.e. not exceed the specified migration limits).

Manufacturers must ensure that their polyurethane products meet this standard before they can be marketed for food contact. Manufacturers or importers of food contact materials must comply with 21 CFR 177.1660 to legally market polyurethane-based products for food-related applications in the United States.

To ensure safety, finished polyurethane resins must undergo extractive testing to measure the amount of substances that may migrate into food. Specific test conditions and permissible extractive limits are detailed in this standard. The use of these polyurethane resins is limited to contact with dry foods under the specified conditions.

In short, FDA 21 CFR 177.1660 is required to ensure the safety of polyurethane resins used in food contact applications. This regulation is considered important for the following reasons:

• Protects human health: Polyurethane resins are used in many materials that come into direct contact with food (e.g., conveyor belts, gaskets, and linings). If left unregulated, these materials can leach harmful chemicals into food and pose health risks. Inert monomers, such as isocyanates or solvents, can be toxic. Their degradation products can migrate into food over time. Regulation establishes clear limits and specifications to prevent harmful migration.
• Standardizes security requirements: 21 CFR 177.1660 establishes uniform security criteria across the industry and specifies:
  • Allowed reactants (isocyanates and polyols)
  • Production methods
  • Extraction limits and test conditions

This consistency helps manufacturers know what is allowed and ensures that materials are tested under similar standards.

• Facilitates compliance and market access: Having clear regulation for manufacturers:
  • Provides a compliance roadmap for FDA approval
  • Reduces legal uncertainty and liability risks
  • Enables domestic and international trade as FDA compliance is often required for import and export
• Supports the implementation of the US Food and Drug Administration (FDA): With the implementation of this regulation, the FDA will:
  • A benchmark for the inspection of food contact materials
  • Legal basis for removing non-compliant products from the market
  • Testing and certification guidelines
• Builds consumer confidence: Consumers can be confident that food-contact products meet rigorous safety standards. This supports public confidence in both the food system and the regulatory framework.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services to businesses in accordance with the FDA 21 CFR 177.1660 Tetramethylene terephthalate standard.