Things You'll Need
Instructions
Separate the buttons to be tested.
Heat the pin under the flame of the candle until the tip of the pin is red hot.
Pick up the button and place the pin on an area where the button will not be damaged by the test, such as on the shank at the back of the button or on the inside of the holes of the button. Allow the button to be singed by the pin, causing it to smoke slightly, emitting an odor.
Put the button near your nose and breath in a little of the odor, being careful not to burn yourself.
Refer to a button "odor guide" to determine what the button is made of.