A Guide On How To Identify Plastics

This guide will help you to identify many of the common types of plastics using simple techniques and readily available tools.
These tests should be used only for tentative identification because some plastics require specialised analysis for identification.

Hold a sample of the material to the edge of a flame until it ignites. (Hold in the flame for about 10 seconds if no flame is produced immediately.) If the material burns, note the nature of the smoke, the presence of soot in the air and, if while burning, the sample drips.
Next, extinguish the flame and cautiously smell the fumes. (In identifying the odour, a known sample is most helpful for comparison.) Remember additives may affect results; for example, flame retardants would mask the polymer's normal burning characteristics.

Material No Flame Burns, but Extinguishes
on Removal of Flame Source		 Continues to Burn after
removal of Flame Source		 Remarks
  Odour Odour Colour of Flame Drips Odour Colour of Flame Drips Speed of Burning  
ABS - Acrid Yellow,
blue edges		 No Acrid Yellow,
blue edges		 Yes Slow Black smoke
with soot in air
Acetals - - - - Formaldehyde Blue,
no smoke		 Yes Slow  
Acrylics - - - - Fruity Blue,
yellow tip		 No (cast)
Yes (moulded)		 Slow Flame may spurt
if rubber modified

 

Material No Flame Burns, but Extinguishes
on Removal of Flame Source		 Continues to Burn after
removal of Flame Source		 Remarks
  Odour Odour Colour of Flame Drips Odour Colour of Flame Drips Speed of Burning  
Nylon 6 - - - - Burnt wool Blue,
yellow tip		 Yes Slow  
Nylon 6/6 - Burnt wool
or hair		 Blue,
yellow tip		 Yes - - - Slow More rigid than
Type 6 nylon
Polycarbonates - Faint, sweet
aromatic ester		 Orange Yes - - - - Black smoke
with soot in air
Polyethylene's - - - - Paraffin Blue,
yellow tip		 Yes

 

 Slow Floats in water
Polypropylenes - Acrida Yellowa Yellowa Sweet Blue,
yellow tip		 Yes Slow Floats in water;
more difficult to scratch
than polyethylene
Polystyrenes - - - - Illuminating Gas Yellow Yes Rapid Dense black smoke
with soot in air
Vinyls
Flexible		 - Hydrochloric acid Yellow with
green spurts		 No - - - - Chars, melts
ABS / Polycarbonate - - - - Yellow,
blue edges		 No - - Black smoke
with soot in air
ABS/PVC - Acrid Yellow, blue edges No - - - - Black smoke
with soot in air
PVC/Acrylic - Fruity Blue, yellow tip No - - - - -

 

Material No Flame Burns, but Extinguishes
on Removal of Flame Source		 Continues to Burn after
removal of Flame Source		 Remarks
  Odour Odour Colour of Flame Drips Odour Colour of Flame Drips Speed of Burning  
Epoxies - - - - Phenol Black smoke No Slow Black smoke
with soot in air
Melamines Formaldehyde
and fish		 - - - - - - - -
Phenolics Formaldehyde
and phenolc		 Phenol and wood or paper Yellow No - - - - May crack
Polyesters - Hydrochloric acid Yellow No - Yellow,
blue edges		 No Slow Cracks and breaks
Silicones - - - - - - - - Deforms
Ureas Formaldehyde - - - - - - - -
Polyurethanes - - - - - Yellow No Slow Black smoke
Acetate - Vinegar Yellow
with sparks		 No Vinegar Yellow Yes Slow Flame may spark
Acetate Butyrate - - - - Rancid butter Blue,
yellow tip		 Yes Slow Flame may spark
Ethyl Cellulose - - - - Burnt sugar Yellow,
blue edges		 Yes Rapid -
Nitrate - - - - Camphor White No Rapid -
Propionate - - - - Burnt sugar Blue,
yellow tip		 Yes Rapid -
Chlorinated Polyether - - Green,
yellow tip		 No - - - - Black smoke
with soot in air
FEP Faint odor of
burnt hair		 - - - - - - - Deforms; no combustion,
but drips
PRTFE Faint odor of
burnt hair		 - - - - - - - Deforms;
does not drip
CTFE Faint odor of
acetic acid		 - - - - - - - Deforms; no combustion,
but drips
PVF acidic - - - - - - - Deforms
                   

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