March 16, 2025 – Reusing Plastic Bottles for Food Storage: A Hidden Health Hazard
In an effort to be eco-friendly, many people wash and reuse mineral water and soda bottles for storing soy sauce, vinegar, or even rice and grains. However, what seems like a sustainable practice may actually pose significant health risks.
Why is reusing these plastic bottles not recommended? The truth is, not all plastics are created equal. They often bear a triangular arrow symbol with a number from 1 to 7, indicating different resin specifications that determine the plastic’s properties and uses.
The bottles we commonly use for mineral water and beverages are mostly made of PET, labeled as number 1. PET is lightweight, odorless, chemically stable, and has good gas barrier properties, making it an ideal choice for food packaging. However, when reused or stored improperly, PET bottles can become unsafe.
According to the Color Masterbatch Industry Network, changing the purpose of a plastic bottle, such as using it to store vinegar, can lead to the release of toxic substances due to changes in the liquid’s pH level. Studies have shown a significant increase in the migration of antimony, a harmful substance, in PET bottles containing acetic acid. Furthermore, PET is not heat-resistant, and foods or liquids exceeding 70°C can cause the bottle to deform and release harmful chemicals. Some people store oil in plastic bottles near stoves, where high temperatures accelerate the migration of harmful substances.
Plastic bottles also age over time, leading to an increased migration of harmful substances. Using plastic bottles to store rice, spices, or other ingredients for years without replacement is actually unsafe.
So, how harmful are these migrating substances to the human body? Antimony is a metal with biological toxicity that can damage various organs when ingested long-term. Plasticizers like phthalates can disrupt the endocrine system and increase cancer risks.
How should we properly use plastic products? Besides PET, there are other common plastics in our lives. For instance, number 2 HDPE has slightly higher heat resistance but is not recommended for food storage. Number 3 PVC is commonly used in daily necessities, and plastic wrap should not be heated at high temperatures. Number 4 LDPE can withstand temperatures around 90°C but will release harmful substances above 110°C. Number 5 PP is heat-resistant and the only plastic safe for microwave use. Number 6 PS has poor heat resistance and is not recommended for reuse. Number 7 OTHER includes various resins and blends, such as PC, which is heat-resistant and impact-resistant but should avoid containing hot foods and should be discarded immediately if damaged.