Even though there are only six commonly used plastics there are hundreds of others, along with hundreds of combinations of different plastics used together and a wide range of different additives.
The first step is to look for a plastics identification code.
If there is none, exact identification of the plastic is not really possible without sophisticated and expensive equipment.
There are however a number of simple tests you can use:
- Examining the material.
- Cutting a small sliver.
- Floating the plastic in water - the specific gravity test.
- Conducting flame tests.
We recommend ?Know Your Plastics? published by the Plastics and Chemicals Industries Association of Australia for detailed instructions. Copies can be ordered at http://www.pacia.org.au/
Please ensure that you use normal safety precautions when testing plastic types.