How to distinguish the plastic cup is PP or PET or PVC

The disposable plastic cup is composed of PP, PET, or PVC.

The disposable plastic cup is composed of PP, PET, or PVC. To discern its composition, examine the triangle mark on either the bottom or the lid of the cup. Within this triangle, Arabic numerals ranging from 1 to 7 indicate various properties and applications of the plastic material.


This system serves as a form of plastic identification, aiding in determining the cup's composition. Refer to the illustration below for clarification:


1. If you spot the number "5" imprinted at the base of a disposable plastic cup, it signifies that the plastic material is PP, or polypropylene. This material is commonly used in items like soy milk bottles, yogurt bottles, juice drink bottles, and microwave oven lunch boxes. With a melting point of 167°C, PP is the lone plastic box suitable for microwave use, provided it's thoroughly cleaned for reuse.


It's essential to highlight that certain microwave oven lunch boxes feature a PP body (No. 5) but a PE cover (No. 1). Since PE cannot withstand high temperatures, it should not be placed in the microwave along with the PP body.


2. When you encounter the number "1" on the underside of a disposable plastic cup, it indicates that the plastic material is PET, or polyethylene terephthalate. Commonly found in mineral water bottles, carbonated beverage bottles, etc., PET tends to deform when exposed to temperatures exceeding 70°C, potentially releasing harmful substances.


After around 10 months, No. 1 plastic may emit the carcinogen DEHP. It's advisable not to expose it to prolonged sunlight in cars and avoid using it for alcohol or oil storage.


3. Discovering the number "3" etched at the bottom of a disposable plastic cup signifies that the plastic material is PVC, or polyvinyl chloride. PVC is utilized in various items like raincoats, building materials, plastic films, and plastic boxes due to its favorable plasticity and low cost. However, with a heat threshold of 81°C, PVC can generate harmful substances at high temperatures, rendering it unsuitable for food packaging. Its cleaning process is arduous, leading to potential residue accumulation, and PVC is not recommended for recycling.


Additional Details:


When acquiring disposable plastic tableware items, consumers should heed the following recommendations:


1. Check the Labeling


When purchasing disposable plastic tableware, consumers should inspect for essential information like the QS mark, production license number, manufacturer details, and production address. These details ensure product quality assurance. Additionally, during usage, take note of any indications against microwave heating to avoid any mishaps.


2. Assess the Packaging


Opt for well-packaged disposable plastic tableware products. Pay attention to the production date and shelf life, selecting items within their shelf life to prevent bacterial growth and mold formation.


3. Examine the Appearance


Select disposable plastic tableware with a smooth surface and uniform color. It's advisable to choose colorless transparent products without decorative patterns.


4. Assess the Odor


Before use, sniff the product for any peculiar odors. This step helps prevent contamination with food and ensures food safety.


5. Check the Hardness


Avoid excessively soft products, as they may indicate lower quality. Opt for items with appropriate hardness for better performance.

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