Characteristics and usage scenarios of tableware of various materials

Most take-out food packaging uses disposable plastic lunch boxes and other plastic tableware. The correct use of plastic tableware is closely related to food safety and anti-food waste.

1.Material characteristics and usage scenarios of mainstream plastic tableware

1.1: PET (polyethylene terephthalate)

Polyethylene terephthalate (PET), commonly known as polyester resin, is a crystalline saturated polyester. It is a milky white or light yellow, highly crystalline polymer with the advantages of high transparency, good barrier properties, non-toxicity, odorlessness, good hygiene and safety. It is mostly used in pre-packaged drinking water, juice, and carbonated beverage bottles. It is not resistant to high temperatures. When the temperature exceeds 70°C, it will deform and release harmful substances. It cannot be used repeatedly, cannot be exposed to the sun, cannot hold hot drinks or be used for heating.

1.2: HDPE (High-density polyethylene)

High-density polyethylene (HDPE), made of white powder or granules, has good heat resistance and cold resistance, good chemical stability, high rigidity and toughness, and feels like wax. Compared with No. 1, it has poor transparency and is often used in milk bottles and buckets, but its temperature resistance is higher than No. 1, reaching 100°C. It is difficult to clean and is not recommended for reuse.

1.3: PVC (polyvinyl chloride)

PVC is slightly yellow and translucent, has certain strength and toughness, good plasticity, and poor stability to light and heat. It is commonly used in building materials, wires and cables, etc., but is rarely used in food packaging at this stage because of the residual carcinogen vinyl chloride monomer (VCM) during the production process. It cannot be used repeatedly and cannot come into contact with high-temperature and high-fat foods.

1.4: LDPE (Low-density polyethylene)

Low-density polyethylene (LDPE) is the lightest variety of polyethylene resin. It is milky white and has good softness, extensibility, electrical insulation, transparency and easy processing. It has good chemical stability and alkali resistance. It is mostly used in plastic wrap and bags. It is much safer than No. 3 and can be used to hold cooked food and hot food, but the temperature should not exceed 110℃, otherwise it will melt. Due to its poor heat resistance, it should not be used to heat food in a microwave oven.

1.5: PP (polypropylene)

Polypropylene (PP) is a thermoplastic synthetic resin with excellent performance. It is a colorless, translucent, thermoplastic, lightweight general-purpose plastic with chemical resistance, heat resistance, electrical insulation, good mechanical properties and wear resistance, and high temperature resistance up to 130°C. Due to its high temperature resistance, high hardness, and stability to organic solvents such as acids and alkalis and greases, it is mainly used in microwave lunch boxes, beverage cups, etc., and is widely used in take-out disposable lunch boxes. Whether it can be reused should be determined based on the product design purpose.

1.6: PS (polystyrene)

Polystyrene (PS) is easy to process and has the advantages of low cost, corrosion resistance, good electrical insulation, and good printability. The disadvantages are low impact strength, easy cracking at low temperatures, and weak heat resistance. It is often used in snack boxes and fast food boxes. It is not suitable for microwave ovens and cannot hold high-temperature and acidic and alkaline foods.

1.7 (Melamine resin)

In addition to the above 6 types of plastic materials, melamine is also widely used. Melamine tableware, also known as imitation porcelain tableware, is made of melamine and formaldehyde as the main raw materials, and is formed by molded thermosetting reaction. It looks similar to ceramic tableware, is light, not easy to break, and has low cost. It is commonly seen in canteens, restaurants, and repeatedly used plates and bowls in families. Melamine tableware is easy to deform when exposed to high temperatures, cannot be used in microwave ovens or ovens, and cannot be scrubbed with steel wool. If it is worn, cracked, or stained, it should be replaced in time.

2. Consumer recommendations

2.1 Pay attention to the label

The smallest sales package or product label of the product should be marked with the production license mark, and should also indicate "food contact" "food packaging" and other similar terms, or a spoon and chopsticks logo. The label content should also include the product name, material, declaration of conformity, name, address and contact information of the manufacturer and (or) distributor, production date and shelf life (when applicable). Products with special use requirements should indicate the method of use, precautions, purpose, use environment, use temperature, etc.

2.2 Carefully check the appearance

Purchase clean, flat, uniformly colored, and odorless plastic tableware. Do not have bubbles, holes, cracks, or other problems. Try to choose tableware that has no prints or dyes on the food contact area, but only the natural color of the material.

2.3 Avoid high temperature use

Except for No. 5 PP material, the biggest "enemy" of other types of plastic tableware is high temperature. When using an oven, steamer, or microwave to heat food, in addition to identifying the PP material, you should also check whether the product is marked with "bake-friendly" or "microwave-friendly" and avoid putting food and plastic packaging into the microwave for heating. When steaming and sterilizing plastic baby bottles, tableware, and toys, pay attention to the applicable temperature range of the material and avoid long-term steaming.

2.4 Avoid repeated usage

Most takeaway plastic lunch boxes are disposable products and cannot be used to store food for a long time or repeatedly. Pre-packaged beverage bottles made of PET material cannot be reused, let alone hot water. Only melamine tableware and PP tableware designed and manufactured for long-term use can be reused. After a period of use, if yellowing, discoloration, or cracking occurs, they should be replaced in time. For tableware used for a long time in complex scenes, it is best to choose transparent glass, pure white ceramics and other materials with better durability and stability.