Plastic has become a very close material to our life. We never leave plastic uses in our daily activities and one of the most common practices is using plastic as our food and drink containers. Plastic food containers have been produced in several types, from different materials, and intended for different purposes and uses. Having practical knowledge about symbols and materials of plastic is important for us when we decide to use plastic food containers.
Types of plastic are categorized by materials consisting them. Plastic which are safe for food container should be free from dangerous substances like Bisphenol-A or commonly abbreviated BPA, Polyvinyl Chloride or PVC. BPA is used in plastic production to make it clear and hard while PVC is often used together with phthalates to make flexible plastic. Problem arises when those harmful substances leach out of the plastic food container and contaminate food or water it contains. It happens when we use the container for hot food/water, or when the container is scratched or broken.
We can practically identify types of plastics based on their symbols and numbers inside the triangle which are usually found at the bottom of a plastic food container. Those symbols are as follows:
PETE or PET (Polyethylene terephthalate) is usually used in water and soft drink, cooking oil, mouthwash bottles and it is only for single use only. Never use it for hot water or food.
HDPE (High Density Polyethylene) plastic is usually used for milk jugs, cleaning solution containers, garbage bags, juice bottles, household cleaner bottles, shampoo bottles, shopping bags, motor oil bottles, butter and yogurt tubs, and cereal box liners. This kind of plastic is also intended for single use only.
V or PVC (Polyvinyl chloride) plastic is normally used for wrapping (cling wrap), shampoo bottles, window cleaner and detergent bottles, cooking oil bottles, and many other containers. Because PVC is tough and weather resistant, it is also widely used for piping. However, PVC may release dioxins which is harmful to health when heated, so never burn this plastic.
LDPE (Low Density Polyethylene) is used for food containers, dry cleaning and shopping bags, tote bags, clothing, furniture, carpet, and soft /flexible bottles. This kind of plastic has strong flexibility and can be safely recycled or reused.
PP (Polypropylene) is the most suitable material for food container and baby bottles. Due to its high melting point, this plastic is used for yoghourt, syrup, ketchup containers, either for cold or hot foods.
PS (Polystyrene) is used in disposable plates, soft styrofoam cups, and food boxes and is commonly used when we buy coffee and food at take-away restaurants. This plastic is also used for trays, foam packaging, CD cases, ice buckets, paints, egg cartons, and building insulation. Nonetheless, the same as PVC, polystyrene can release toxin when it it heated, so we must be extremely careful when we use it for hot food and drink containers.