Plastic container markings: types and interpretation of plastic container markers

Today, plastic is an integral part of our daily lives. From milk and yogurt to mineral water, most products are sold in plastic containers. While plastic has successfully replaced glass and paper due to its durability and low cost, safety remains a critical concern. This is why manufacturers are required to provide clear information about the materials they use.

This article explains the various markings and symbols found on plastic products to help you make informed decisions.

Standards for Plastic Tableware

Manufacturers must adhere to strict requirements to ensure their products meet both consumer needs and international safety standards:

• Safety: The plastic must be non-toxic and compliant with international food safety regulations.
• Chemical Resistance: High resistance to reagents like alkalis and acids.
• Thermal Resistance: Capability to withstand high temperatures for reheating or serving hot liquids.
• Thermostatic Properties: Ensuring the container is comfortable to hold after being microwaved.
• Low-Temperature Resistance: Safe for food storage in refrigerators and freezers.
• Versatility: Variety in sizes, shapes, volumes, and colors.
• Structural Integrity: The material must be resilient and maintain its shape.
• Recyclability: Ease of disposal or secondary processing.

Plastic Resin Identification Codes (1–7)

The graphic symbol of three arrows forming a triangle contains a number from 1 to 7, usually located at the bottom of the packaging. Each number represents a specific chemical composition.

01 PET (PETE)

Polyethylene Terephthalate: The most common plastic for food containers, water bottles, and juices.

• Safety: It is intended for single use only. Studies suggest that liquids in contact with PET can absorb estrogen-like compounds over time. Avoid reusing PET bottles.

02 HDPE (PE-HD)

High-Density Polyethylene: Used for milk jugs, detergent bottles, and furniture.

• Safety: Known for its high strength and resistance to acids. It is considered one of the safest and most eco-friendly plastics as it is highly recyclable and safe for reuse.

03 PVC (V)

Polyvinyl Chloride: Found in window frames, medical tubing, and non-food packaging.

• Safety: PVC is potentially hazardous. It can release toxins (dioxins) especially when heated or burned. It should never come into direct contact with food or be heated in a microwave.

04 LDPE (PBD)

Low-Density Polyethylene: Used for grocery bags, cling film, and squeezable bottles (ketchup/mustard).

• Safety: Considered one of the safest plastics for human health. It is durable and can be used multiple times.

05 PP

Polypropylene: The second safest material for food storage.

• Safety: It has high heat resistance, making it the primary material for microwave-safe containers, hot drink cups, and yogurt tubs. It is safe for multiple uses.

06 PS

Polystyrene: Used for disposable coffee lids, foam food containers, and plastic cutlery.

• Safety: PS is considered toxic and should be avoided where possible. It can leach styrene, especially when heated, which is harmful to the nervous system.

07 O (OTHER)

This category includes a mix of plastics or new resins like Polycarbonate.

• Safety: These may contain BPA (Bisphenol A), which is linked to endocrine and neurological issues.
• Exception: Look for stamps like “BPA-FREE” or “BPA 0%”. If no additional information is provided, exercise caution and avoid heating these containers.

Operating Symbols and Icons

In addition to the resin code, you may find other important icons:

• Glass and Fork: Indicates the material is certified for direct food contact.
• Green Dot (Der Grüne Punkt): Signifies that the manufacturer participates in a packaging recovery and recycling program.
• Mobius Loop (Recycling Symbol): Indicates the material is recyclable. Often contains a percentage (%) indicating how much of the packaging is made from recycled content.

Numerical Guide for General Recycling:

• 1–19: Plastic
• 20–39: Paper/Cardboard
• 40–49: Metal
• 50–59: Wood
• 60–69: Textiles/Fabrics
• 70–79: Glass

Final Advice

Understanding these symbols is the key to safe and eco-friendly consumption. Always check the bottom of your containers, especially before reheating food or reusing a bottle.

Optipak is committed to transparency and high standards. We produce our packaging using safe, high-quality polymers (primarily PP and PET) to ensure the health of our customers and the preservation of our planet.