With the introduction of the updated standards titled "Food Safe Self-adhesive Plastic Film," there have been significant changes from the earlier 1989 standards. This new standard encompasses both PVC and PVDC films, alongside the previously recognized PE films. These standards are now stricter regarding the raw materials utilized, emphasizing the use of food-safe raw materials. PVC films must be labeled with cautions like "Avoid contact with fatty foods" and "Not safe for microwaving." For films suitable for microwaving, explicit labeling indicating "Microwave-safe," the method of heating, and the highest temperature tolerance is mandatory.
Moreover, the packaging of the wrap should specify product details such as the material, oxygen, carbon dioxide, and moisture permeability. The manufacturer should also clearly label the product's dimensions and net weight.
Types of Plastic Wraps
1. PE Film: Ideal for packaging foods like biscuits, peanuts, fresh produce, and frozen items. While often used in supermarkets, it isn't designed for high-temperature applications. 2. PVC Film: Suitable for wrapping vegetables. However, it should not come in direct contact with cooked meals or fatty products. Microwaving or high-temperature usage is not advised. 3. PVDC Shrink Film: Designed for wrapping processed foods, ham, and the like. With superior clarity and sealing properties, it's usable at temperatures up to 140°C, albeit at a higher cost. Supermarket Packaging Updates
In light of these new standards prioritizing human health, changes in packaging have been observed. Major supermarkets are shifting towards the new packaging standards, with older packaging versions becoming less prevalent.
Most wraps now have a "food-grade" tag, primarily made of PE. Directions on the packaging remind users to allow ventilation when microwaving by leaving a small opening or piercing the wrap.
Understanding the Risks of PVC Film
What makes these wraps different? Marketed wraps generally fall into three categories: PE, PVC, and PVDC. While PE is the go-to material for most food wraps in supermarkets, PVC, despite its versatility, poses potential health concerns.
Microwaves often reach temperatures between 200°C-300°C, exceeding the melting points of both PE and PVC, which are 127°C and 120°C respectively. Melting these films could cause them to leach into food. PE is relatively safer since it doesn’t require added plasticizers.
Conversely, PVC necessitates ample plasticizers to make it pliable. These plasticizers can release harmful compounds, especially when in contact with fatty foods, which might lead to various health issues, including cancer.
Distinguishing PE and PVC Films
1. Visual Examination: PE appears milky, making food less visible. PVC, on the other hand, is glossy, clear, with a faint yellowish tinge.
2. Physical Test: PE is softer but tears easily, while PVC is more resilient and slightly sticky.
3. Fire Test: When burnt, PE Shrink Film burns quickly with a candle-like odor, whereas PVC releases a strong, unpleasant smell. Guidelines for Heating with Plastic Wrap
Wang Hongling, a seasoned dietitian, advises that using PE beyond its temperature threshold or PVC at high temperatures can release harmful substances that might harm human detoxifying organs like the liver and kidneys. With time, these substances might lead to serious illnesses, including cancer.
Hence, when using wraps for heating, ensure that the wrap is suitable for the purpose, adhere to safe temperatures, and avoid direct contact between the wrap and food. Furthermore, even if PE is generally safer, quality can vary. Be wary of cost-saving measures by manufacturers and always opt for "food-grade" labels.
