Influenced by recycling proponents around United States, the Society of the Plastics Industry, Inc. introduced Resin identification coding system. It was in 1988 when this scheme of separating (or grouping) plastic resin types to make it easier for recyclers to sort them out and to have a more systematic waste management system, was introduced.

Guidelines in the Use of Recycling Number

The Society of the Plastics Industry in cooperation with the Federal Trade Commission (FTC) agreed on the following guidelines in using the code:

This complies with the laws in 39 states wherein the code must be used on bottles and rigid containers
This is used to identify resin (a type of plastic) content only.
The code, while it helps in waste management and recycling activities, must not be conspicuous so as to affect sales of a product
The code must, in any way, never be altered
No additional markings such as ?recyclable? may be placed near the symbol, nor should there be any claims of any products recyclability placed anywhere near it.
The ?? symbol, whenever it would fit, must be molded or permanently imprinted on all gallon containers from 8 ounce to 5 gallon capacity
Placement of the symbol must be as close to the center of the container bottom

To help you recycle efficiently, below are the 6 different symbols that are helpful in creating your own household waste management and the description of plastic items that are good for recycling.

1 PET (or PETE) ? Poly(ethylene terephthalate) PET is a clear, and tough resin that can contain gas and moisture. These are commonly used in bottles and other injection molded product containers. This resin is a good candidate for recycling as they come in great volumes in waste management systems, in the form of bottles for beverages, catsup, beer, jams, peanut butter, etc. Major industries recycle these for major uses such as textiles, carpet, films, ink cartridges and moldings.

2 HDPE ? High-density Polyethylene ? HDPE commonly found in may types of plastic bottles. Its high resistance to chemicals makes it the preferred material for packaging household and industrial material such as detergents, conditioner, shampoo, bleach, etc. Proper waste disposal, i.e., segregating, would have these items for recycling and become plastic shopping bags, wire and cable covering, re-usable shipping containers, etc.

3V Poly (vinyl cloride) ? commonly known as PVC, these are categorized into two groups, namely, rigid and flexible materials. While used containers made from these are also highly sought for recycling, these have many industrial and household uses. .

4 LDPE ? Low-density Polyethylene ? commonly found in film application uses because of its toughness, it is relatively transparent and flexible.

5 PP ? Polypropylene ? this is good for containing very hot fluids as it has very good chemical resistance and is a strong material. A very good example would be Tupperware products (which have their own recycling system), diapers, bottle caps and closures, etc.

6 PS ? Polystyrene ? this is a very versatile plastic material that can either be rigid or foamed. Examples are coffee cups, bakery shells, Styrofoam insulation, etc. Polystyrene can also be combined with rubber to produce high impact polystyrene, which is good for uses that require toughness.

7 OTHER ? this means that the package is made up of a resin type that is not included in any of the above-mentioned six, or it usually is a package that contains a combination of the previously mentioned codes.