ETHYLENE VINYL ACETATE (EVA) COPOLYMERS

Introduction

Ethylene Vinyl Acetate (EVA) is a specialized copolymer of ethylene and vinyl acetate. It is a thermoplastic material that is widely used in food contact applications due to its excellent flexibility, transparency, and resistance to UV light and weathering. EVA is a member of the polyolefin family and is known for its rubber-like softness and flexibility, which can be tailored by varying the vinyl acetate content. It is used in a variety of food packaging applications, including films, seals, and liners.

CAS Number

The polymer has a CAS Number of 24937-78-8. The monomer vinyl acetate has a CAS Number of 108-05-4.

Synonyms

• Poly(ethylene-co-vinyl acetate)
• Ethylene/VA Copolymer
• EVA
• Ethylene-Vinyl Acetate Latex

Topic Headings

1. Primary Food Contact Applications (list form)

• Packaging films — Used for its excellent flexibility and low-temperature performance.
• Seals and gaskets — Employed in closures and sealing gaskets for food containers.
• Adhesives — Used in adhesives for food packaging laminates.
• Coatings — Applied as a coating on various food contact materials.
• Medical and food packaging — Suitable for applications requiring high clarity and flexibility.

2. Mechanism of Food Contact Compliance (paragraph form)

EVA copolymers are regulated as indirect food additives in many jurisdictions. In the United States, they are listed as indirect additives used in food contact substances under FDA regulations, such as 21 CFR 175.300 for adhesives and coatings. The safety of EVA for food contact is based on the principle that the polymer is inert and does not migrate into food at harmful levels. Compliance requires that the specific EVA resin meets the compositional requirements set by the regulatory body.

3. Physical and mechanical properties (list form)

• Appearance — Clear to translucent, flexible film or solid.
• Flexibility — Ranges from rubber-like to plastic-like, depending on vinyl acetate content.
• Transparency — Excellent optical clarity.
• UV resistance — Good resistance to UV light and weathering.
• Adhesion — Good adhesion to various substrates.
• Low-temperature performance — Excellent flexibility and high elongation at break at low temperatures.
• Chemical resistance — Generally resistant to water and many chemicals, but incompatible with strong oxidizing agents and bases.

4. Safety and Regulatory Status (paragraph form)

EVA copolymers are considered safe for food contact when used in compliance with relevant regulations. They are approved for food contact applications in the US, EU, and many other regions. The polymer is inert and does not pose a significant health risk. The primary safety concern is the potential migration of residual monomers or additives, which is strictly controlled by regulatory limits. As a polyolefin, EVA is generally considered to be non-toxic and is widely used in food packaging and medical applications.