Food Grade Plastic

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What Is Plastic?

Plastic is made from hydrocarbons derived from petroleum or natural gas. The hydrocarbons are formed into chains called polymers, or plastic resins. By combining hydrocarbon molecules in different ways, different types of plastic can be created.

What Is Food Grade Plastic?

The U.S. Food & Drug Administration (FDA) requires that plastics used in food packaging be of greater purity than plastics used for non-food packaging. This is commonly referred to as food grade plastic. Plastics used to package pharmaceuticals are held to an even higher standard than food grade.

Food grade plastic does not contain dyes or recycled plastic deemed harmful to humans. However, this does not mean that food grade plastic cannot contain recycled plastic. The FDA has detailed regulations concerning recycled plastics in food packaging.

Another aspect of food grade plastic is matching the appropriate type of plastic to the food in question. Foods that are highly acidic or that contain alcohol or fats can leach plastic additives from the packaging or container into the food. As a result, you should only use plastic containers that are FDA approved for the particular type of food the plastic will come into contact with.

Finally, it should be noted that a plastic container can no longer be considered food grade if it has been used to store non-food items like chemicals, paint, or detergent.

Types Of Plastic

In the United States, the following codes represent the seven categories of plastic used in nearly all plastic containers and product packaging:

1 - PET PET or PETE (polyethylene terephthalate) is a clear, tough polymer with exceptional gas and moisture barrier properties. PET’s ability to contain carbon dioxide (carbonation) makes it ideal for use in soft drink bottles.Examples: Soft drink bottles, detergent bottles
 
2 - HDPE HDPE (high density polyethylene) is used in milk, juice and water containers in order to take advantage of its excellent protective barrier properties. Its chemical resistance properties also make it well suited for items such as containers for household chemicals and detergents. Most five gallon food buckets are made from HDPE.Examples: Milk bottles, shopping bags
 
3 - V Vinyl (polyvinyl chloride, or PVC) provides excellent clarity, puncture resistance and cling. As a film, vinyl can breathe just the right amount, making it ideal for packaging fresh meats that require oxygen to ensure a bright red surface while maintaining an acceptable shelf life.Examples: Plastic food wrap, shrink wrap, garden hoses, shoe soles
 
4 - LDPE LDPE (low density polyethylene) offers clarity and flexibility. It is used to make bottles that require flexibility. To take advantage of its strength and toughness in film form, it is used to produce grocery bags and garbage bags, shrink and stretch film, and coating for milk cartons.Examples: Squeeze bottles, dry cleaning bags
 
5 - PP PP (polypropylene) has high tensile strength, making it ideal for use in caps and lids that have to hold tightly on to threaded openings. Because of its high melting point, polypropylene can be hot-filled with products designed to cool in bottles, including ketchup and syrup. It is also used for products that need to be incubated, such as yogurt. Many Cambo, Tupperware and Rubbermaid food storage containers are made from PP.Examples: Bottle caps, take-out food containers, drinking straws
 
6 - PS PS (polystyrene), in its crystalline form, is a colorless plastic that can be clear and hard. It can also be foamed to provide exceptional insulation properties. Foamed or expanded polystyrene (EPS) is used for products such as meat trays, egg cartons and coffee cups. It is also used for packaging and protecting appliances, electronics and other sensitive products.Examples: Plastic foam, packing peanuts, coat hangers
 
7 - Other Other denotes plastics made from other types of resin or from several resins mixed together. These usually cannot be recycled.

Another important type of plastic is polycarbonate, a clear shatter-resistant material used in restaurant food storage containers and recently in the Rubbermaid Stain Shield line of home food storage containers.

Why do we need different types of plastics, anyway? This excerpt from the American Plastics Council Web site explains it well.

“Copper, silver and aluminum are all metals, yet each has unique properties. You wouldn’t make a car out of silver or a beer can out of copper because the properties of these metals are not chemically or physically able to create the most effective final product. Likewise, while plastics are all related, each resin has attributes that make it best suited to a particular application. Plastics make this possible because as a material family they are so versatile.”

Not All HDPE Containers Are Food Grade

There is a common misconception that all containers made of white plastic or HDPE plastic bearing the HDPE "2" plastic symbol symbol are food grade containers. This is not true.

If you are considering the purchase of a container from some place other than a kitchen or restaurant supply store, and the container is not clearly labeled as “food safe” or being made of food grade plastic, then you should assume that it is not food grade and you should not brine in it—unless you line it with a food grade plastic bag.

This entry was posted on Thursday, June 3rd, 2010 at 9:16 am and is filed under Bespoke Aquarium, RO Water, Water Change. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.