Buring Polyethylene

Name: John
Status: other
Grade: other
Location: PA

Question: This question is in response to an answer provided by Vince Calder on 
November 16th 2002 in regards to burning polyethylene and polyethylene 
terephthalate. It was stated that since PE and PET are simple hydrocarbons, 
their combustion products are relatively harmless. I have since discovered 
research that disagrees with this statement. Specifically, when burning 
plastics, it is difficult to determine just what the combustion products 
will be as the polymer chains can fracture at irregular intervals and react 
with themselves to form a large variety of compounds, some of them 
potentially toxic. Are you aware of any further work that has been done 
concerning PE and PET combustion products?
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I will qualify my initial response. I was thinking "chemically". My initial 
response was based on the assumption that the PE and PET burned in the presence 
of sufficient oxygen to have complete combustion. In that case I stand by my 
original response.

However, J. Kunkel makes a valid point. That assumption may not always be the 
case "in the real world".  In the absence of sufficient oxygen he is correct 
that there can be products of incomplete combustion, decomposition, and side 
reactions that produce toxic chemicals.

There is another qualification that should be added too. In actual use 
"plastics" are usually "formulated" products, containing pigments, and various 
additives that can have varying levels of toxicity -- a case in point being the 
lead found in toys imported from China.

Under oxygen "starved", "low temperature" conditions there are some nasty 
decomposition products that can form.

Sorry for thinking "in the box".


Sources for J. Kunkel:
A Google search on the term: "combustion products plastics" got these "hits" 
in addition to many other resources. The combustion products of various plastic 
products is a heavily studied area for practical reasons.

Vince Calder

http://www.stormingmedia.us/46/4687/A468703.html

http://jfs.sagepub.com/cgi/content/refs/12/1/63

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&uid=613970&cmd=showdetailview&indexed=google


Vince Calder
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