Identify whether plastic products are toxic

There are many methods for identification, such as appearance method, specific gravity method, solvent method, boiling water immersion method, and combustion method. The method that is relatively simple and accurate and feasible is the combustion method. It is introduced as follows:
Cut the sample into small strips and place it in a tweezers. Use a lighted alcohol lamp (such as a no-alcohol lamp and a lit candle instead) to see how easy it is to burn, how it will be after leaving the fire, the color of the flame and smoke, and the burning The phenomenon and the emitted odor can be combined with what type of plastic the judge is now.
Polyvinyl chloride plastic: non-flammable, away from the fire, flame and smoke color at the bottom of the green tip yellow, softening and white smoke when burning, after the extinction can have a phenomenon of drawing, there is the smell of hydrochloric acid gas.
Polyethylene plastic: flammable, continue to burn after leaving the fire, flame and blue top of the smoke at the end of the flame, melting continuously dropping when burning, emitting a flavor similar to burning paraffin.
Polypropylene plastic: flammable, follow-up fire from the fire, the flame color for the bottom blue top yellow, burning constantly dropping under the dripping, there is the taste of oil.
Polystyrene plastic: flammable, continue to burn after leaving the fire, flame and smoke color is orange, black smoke, it is clear that black charcoal fly to the air, emitting a unique styrene odor.
Bakelite: hardly flammable, extinguishes after leaving fire, yellowish flames and smoke, swells and cracks when fired, and wood burns with phenol odor.
Urine aldehyde plastic: It is flame-retardant, and it is extinguished after leaving the fire. The flame and smoke are yellow, the tip is light blue, and there is swelling and cracks when burning, giving off a pungent urea and formaldehyde.
Nylon plastic: Slowly extinguishes after leaving the fire slowly, the flame is yellow, continuously dripping and bubbling when burning, similar to the smell of burned wool.