The diagram above indicates most of the known chemicals and substances in the diluted bitumen (dilbit) in the tar sands pipeline. The large black molecules are different molecular forms of the aromatic hydrocarbon called asphaltene, the black tarry substance which is processed to obtain gasoline and other refined products. This tarry asphaltene is diluted by a mixture of chemicals called a diluent, often natural gas condensate, which contains a group of dangerous carcinogens and neurotoxins, including benzene, toluene, ethylbenzene, xylenes, cumene, and hexane. There are other diluents used which are of unknown composition.There are a lot of sulfates in the mixture, which makes it highly acidic. It is the acidic nature of the mixture which makes it corrosive. Most sand from the tar sands is removed before it is piped, but there is still some fine sand and silt in the mixture. All of the chemicals in the dilbit are not known because the industry has declared it to be proprietary information. When there is a tar sands pipeline leak, the highly volatile aromatic hydrocarbons in the diluent begin to vaporize and the air becomes highly polluted with toxic vapors. If in water, the tarry black asphaltene sinks to the bottom, where it is almost impossible to clean up.
http://my.firedoglake.com/stevehorn1022/2013/04/30/study-30-toxic-chemicals-at-high-levels-at-exxon-arkansas-tar-sands-pipeline-spill-site/In the aftermath of ExxonMobil’s Pegasus tar sands pipeline spill of over 500,000 gallons of diluted bitumen (dilbit) into Mayflower, AR, air quality in the area surrounding the spill has been affected by high levels of cancer-causing chemicals. Includes a very good 58 minute video interview with a resident. April 30, 2013. http://www.gcmonitor.org/article.php?id=1672 Independent Air Test at Mayflower Oil Spill Reveal 30 Toxic Chemicals at High Levels. The chemicals found in the samples include benzene, toluene, ethylbenzene, n-hexane, and xylenes. Breathing in both ethylbenzene and benzene can cause cancer and reproductive effects, while breathing in n-hexane can damage the nervous system and usher in numbness in the extremities, muscular weakness, blurred vision, headaches, and fatigue. 4/26/13
One of the early papers in the history of bituminous Alberta sands by KA Clark, the leader in the research for years:http://188.8.131.52/publications/REP/PDF/REP_58.pdfThe components of the bitumen in Athabasca Bituminous Sand and their Significance in the Hot Water Separation Process BY DS PASTERNACK AND KA CLARK, Universtiy of Alberta, 1951.
Tar Sands Protection League is a group of concerned citizens in the Houston, Texas area. We are professionals, including two chemists (one PhD), one retired chemical engineer with experience in oil pipelines, and one LCSW, PhD. We have put a lot of time into preparing this website so that we can bring people the most accurate information available on the web about tar sands and the hazards of tar sands pipelines. You may contact us via the CONTACT page at the end of the website.