Plastic Packaging Materials: Types, Properties, and Uses in Food Industry

Plastic packaging materials are everywhere in the food industry – from the water bottle you grab on a hot day to the yogurt container in your refrigerator. These synthetic polymers have become the backbone of modern food packaging because they offer a rare combination of being lightweight, durable, cost-effective, and highly customisable. But not all plastics are created equal. Each type brings a distinct set of properties to the table, and understanding these differences is essential for anyone working in food processing, packaging design, or food safety.

Why plastics dominate food packaging 🔗

Plastics have been the preferred material for food packaging for several decades now. Research published in the journal Future Foods confirms that plastics combine mechanical performance with barrier properties and transparency, making them a cost-effective choice for distributing food products safely. Compared to traditional materials like glass or metal, plastics can be moulded into nearly any shape, made transparent or opaque, and designed to be rigid or flexible depending on the application. They are also significantly lighter, which reduces transportation costs and the carbon footprint associated with shipping.

The food packaging industry classifies plastics using a Resin Identification Code (RIC) – the numbers 1 through 7 that you see stamped on the bottom of plastic containers. This numbering system, managed by organisations like the Society of Plastics Engineers (SPE) and the Plastics Industry Association (PIA), identifies the type of plastic resin used and also guides recycling practices. In the sections below, we’ll look at the major types of plastics used in food packaging, their key properties, and their common applications.

Polyethylene (PE): the most widely used packaging plastic 🔗

Polyethylene is the most commonly used plastic in food packaging globally. It is a polymer made from ethylene monomers and comes in several variants, each with distinct characteristics suited for specific uses.

Low-density polyethylene (LDPE) 🔗

LDPE carries resin identification code #4. It is soft, flexible, and transparent, with a high resistance to moisture, tearing, and chemicals. These traits make it the go-to material for products that need flexibility – grocery bags, bread bags, frozen food packaging, squeeze bottles, and flexible lids. LDPE is also one of the more affordable packaging plastics, which adds to its widespread adoption. However, its lower tensile strength compared to HDPE means it is not suitable for heavy-duty containers.

A related variant, linear low-density polyethylene (LLDPE), offers improved tensile and impact strength along with better heat-sealing qualities. LLDPE is widely used for bottle caps and shrink wraps in the food and beverage sector.

High-density polyethylene (HDPE) 🔗

HDPE, marked with resin code #2, is a tougher and more rigid form of polyethylene. It offers excellent chemical and moisture resistance, superior impact strength, and a good strength-to-density ratio. A classic example: an HDPE milk jug weighs just about two ounces but can hold a full gallon of milk. HDPE is commonly found in juice containers, syrup bottles, cereal box liners, and grocery bags. It is also heat-resistant and recyclable, which makes it popular in both household and industrial food packaging.

According to Piedmont Plastics, HDPE offers low moisture absorption, high tensile strength, and excellent corrosion resistance, and it will not decay, splinter, or harbour dangerous microorganisms. These properties extend its use beyond packaging into food processing equipment like cutting boards, conveyor belts, and bottling lines.

Polypropylene (PP): the heat-resistant performer 🔗

Polypropylene, identified by resin code #5, is a thermoplastic polymer derived from propylene monomers. Its standout feature is its high melting point – it can withstand temperatures up to about 130°C, which makes it the top choice for microwave-safe food containers, hot food packaging, and containers that need to go through a dishwasher cycle.

PP is somewhat stiff but not brittle. It can be manufactured as translucent, opaque, or coloured. You’ll commonly find it in yogurt cups, sour cream and cream cheese containers, syrup packets, and the lids on condiment bottles. Its ability to resist repeated bending without breaking also makes it ideal for hinged-cap closures on sauce and ketchup bottles.

Compared to polyethylene, PP has stronger chemical resistance – particularly against acids – making it a reliable material for packaging acidic food items. However, it only retains its properties above 0°C, which limits its suitability for frozen food applications where PE may be a better fit. Biaxially-oriented polypropylene (BOPP) film is widely used for snack bags, labels, and high-hot-tack applications like packaging rice, nuts, and sauces.

Polyethylene terephthalate (PET): the beverage bottle champion 🔗

PET, also known as PETE, carries resin identification code #1 and is arguably the most recognisable food packaging plastic. Nearly every single-use water bottle, soda bottle, and juice container you encounter is made from PET. It belongs to the polyester family and is produced by polymerising terephthalic acid with ethylene glycol.

PET offers a powerful combination of properties that makes it dominant in liquid packaging. It is lightweight yet semi-rigid with high impact resistance. It provides excellent barrier properties against carbon dioxide (critical for carbonated beverages), oxygen, and moisture. Its crystal-clear transparency lets consumers see the product inside, which is a major advantage for branding and consumer trust. Beyond beverages, PET is widely used for packaging peanut butter, salad dressings, cooking oils, condiments, and bakery trays and produce containers.

A notable property of PET is that it resists microbial growth and does not corrode, making it a safe choice for food storage. A review published in Environmental Chemistry Letters notes that PET’s beneficial properties include light weight, high tensile strength, transparency, and effective gas barrier characteristics. However, PET does not perform well under high heat, so it is not recommended for hot-fill or microwave applications – that’s where PP takes over.

A variant called crystallisable PET (CPET) undergoes additional processing that gives it improved flexibility and heat resistance. CPET can tolerate conventional oven and microwave temperatures, making it suitable for ready-to-eat meal trays and oven-proof packaging.

Polyvinyl chloride (PVC): versatile but increasingly scrutinised 🔗

PVC, marked with resin code #3, is a plastic that combines biological and chemical resistance with flexibility and optical clarity. It is commonly used for tamper-resistant packaging for over-the-counter medications, shrink wraps, and blister packs for products like mints and gum. In food packaging specifically, PVC appears in cling films, oil bottles, and water bottle sleeves.

PVC’s natural resistance to oils makes it useful for packaging fatty food items where product visibility matters. However, the use of PVC in direct food contact applications has become more restricted in recent years. This is largely due to concerns about certain additives – particularly phthalate plasticisers – and the environmental impact of PVC production and disposal. The U.S. FDA has revoked authorisations for 23 phthalates previously allowed in food contact applications, and the European Chemicals Agency (ECHA) has also recommended restrictions on some PVC additives. As a result, many food manufacturers are exploring alternative materials for applications where PVC was traditionally used.

Polystyrene (PS): lightweight and affordable 🔗

Polystyrene, resin code #6, is a hard, colourless plastic that can be produced in solid or foam form. In its foam version (commonly known as Styrofoam), it is used extensively for disposable food containers, hot drink cups, egg cartons, meat trays, and takeaway packaging. PS is also used for deli and bakery trays, plates, and cutlery.

The main advantage of PS is that it is extremely lightweight, low-cost, and easy to mould into detailed shapes. However, environmental concerns are significant – PS takes a very long time to decompose and can leach chemicals into the environment. For this reason, many companies are actively phasing out PS in favour of biodegradable and compostable alternatives.

Other food-grade plastics and emerging alternatives 🔗

Polyamide (Nylon) 🔗

Nylon is a strong thermoplastic with a high melting point, excellent oxygen barrier properties, and resistance to grease, oil, and acidic foods. It also resists scratching and puncturing. Nylon is used in both microwave and conventional cooking applications, often as part of multi-layer packaging films where its barrier properties complement other materials.

Polyvinylidene chloride (PVDC) 🔗

PVDC is a synthetic thermoplastic that provides outstanding oxygen and moisture barrier properties. It is also resistant to heat, chemicals, oil, and grease. PVDC is most commonly used in food and pharmaceutical packaging to extend product shelf life – you may recognise it as the material behind popular cling wrap brands.

Polylactic acid (PLA) and bio-based plastics 🔗

With growing environmental concerns around conventional plastics, bio-based alternatives like PLA are gaining traction. PLA is derived from renewable sources like sugarcane and cornstarch and is used for biodegradable straws, takeaway containers, plates, and bowls. While PLA represents a promising step toward sustainable packaging, it still needs to match the mechanical and barrier performance of traditional plastics for widespread adoption.

Key properties that determine plastic selection for food packaging 🔗

Choosing the right plastic for a specific food product depends on several core properties:

Barrier properties – The ability to block moisture, oxygen, carbon dioxide, and aromas. PET and PVDC are excellent gas barriers; PE variants provide good moisture barriers. Without proper barrier performance, food shelf life decreases significantly.

Heat resistance – For microwave or hot-fill applications, PP is the preferred choice due to its high melting point. PET struggles with heat, while CPET offers a middle ground for oven-safe trays.

Transparency and appearance – PET provides the best optical clarity, making it ideal for products where consumers want to see what they’re buying. PP is typically translucent, while HDPE is opaque.

Mechanical strength – HDPE and PET offer high impact resistance and tensile strength, making them suitable for containers that face rough handling during transport. LDPE is more flexible but weaker.

Chemical resistance – PP leads in resistance to acids and alkalis. HDPE handles chemicals and cleaning agents well. This is critical for packaging acidic foods or for equipment that requires frequent sanitation.

Cost – LDPE and PS are among the most cost-effective options. PP is generally cheaper to produce than PET, though PET’s properties often justify its higher cost for beverage packaging.

Food safety regulations and plastic packaging 🔗

The safety of plastics used in food contact is governed by strict regulatory frameworks. In the United States, the U.S. Food and Drug Administration (FDA) regulates all food contact materials under Title 21 of the Code of Federal Regulations (21 CFR). Plastics intended for food use must be manufactured from approved raw materials, withstand the conditions of their intended use (temperature, acidity, etc.), and not leach harmful chemicals into food above permitted thresholds.

Common food-grade plastics approved by the FDA include HDPE, LDPE, PET, PP, and polycarbonate (with BPA-specific restrictions for infant products). In the European Union, Regulation (EU) 10/2011 governs plastic food contact materials, with ongoing revisions expected to address sustainability and chemical safety concerns. India’s Food Safety and Standards Authority of India (FSSAI) similarly regulates packaging materials under the Food Safety and Standards (Packaging) Regulations.

For food processors and manufacturers, understanding these regulations is not optional. Using a non-compliant packaging material can lead to product recalls, legal liability, and – most importantly – consumer health risks.

Environmental concerns and the road ahead 🔗

The environmental impact of plastic packaging remains one of the biggest challenges the food industry faces. Most conventional food packaging plastics are derived from petroleum, and while materials like PET and HDPE are recyclable, global recycling rates still fall short. Single-use plastics, particularly PS and thin films, often end up in landfills or oceans.

The industry is responding on multiple fronts. Lightweight designs are reducing the total volume of plastic used per package. Chemical recycling technologies are emerging that can break plastics down to their monomers for reuse. Recycled PET (rPET) is already FDA-approved for food contact and is increasingly used in beverage bottles. Bio-based plastics like PLA offer a renewable path, though their performance and infrastructure for composting still need scaling up.

The future of plastic food packaging likely lies in a combination of improved recyclability, bio-based materials, and smarter packaging design – such as active packaging that extends shelf life and smart packaging with freshness indicators – rather than a complete elimination of plastics.

What do you think? Given the trade-offs between performance, cost, and environmental impact, which type of plastic packaging material do you think has the most potential for sustainable food packaging in the coming decade? And should food safety regulations be stricter about limiting specific types of plastics in direct food contact?

References

1. https://www.sciencedirect.com/science/article/pii/S2666086524000341
2. https://www.chemicalsafetyfacts.org/health-and-safety/types-of-plastic-food-packaging-and-safety-a-close-up-look/
3. https://www.p5pkg.com/blog/types-of-plastic-food-packaging/
4. https://www.plastekgroup.com/blog/food-packaging-material-guide/
5. https://www.piedmontplastics.com/blog/food-processing-plastic
6. https://www.acmeplastics.com/content/the-ultimate-guide-to-food-grade-and-food-safe-plastics/
7. https://www.spg-pack.com/en/blog/5-differences-between-polypropylene-and-polyethylene-food-packaging/
8. https://pmc.ncbi.nlm.nih.gov/articles/PMC8755403/
9. https://www.fda.gov/food/food-additives-and-gras-ingredients-information-consumers/phthalates-food-packaging-and-food-contact-applications
10. https://www.restaurantware.com/blogs/take-out-and-delivery/6-types-of-plastics-used-in-food-packaging
11. https://www.fda.gov/food/packaging-food-contact-substances-fcs/inventory-food-contact-substances-listed-21-cfr
12. https://foodpackagingforum.org/news/2024-food-contact-chemical-and-material-policy-outlook