Unlike conventional crude, tar sands poses an elevated risk to human health and safety.
Due to the natural gas condensate, bitumen crude has an increased risk of leaked material exploding at temps above 0°F.
This mixture can be ignited by heat, spark, static charge, or flame.
One of the toxic risks is hydrogen sulfide, a gas which can cause suffocation at 100 ppb.
Tar sand crude also contains benzene, polycyclic aromatic hydrocarbons, and n-hexane -- toxins that can affect the central nervous system. Long time exposure to these chemicals can cause cancer.
Vanadium, nickel, arsenic, and other heavy metals are present in significantly higher quantities in Dilbit than conventional crude. These heavy metals are not biodegradable, and can accumulate in both people and the environment causing a variety of toxic effects.
1.^"Material Safety Data Sheet: Natural Gas Condensates," Imperial Oil, 2002, http://www.msdsxchange.com/english/show_msds.cfm?paramid1=2480179
2.^"Material Safety Data Sheet: Natural Gas Condensate, Petroleum," Oneok, 2009, http://www.oneokpartners.com/en/CorporateResponsibility/~/media/ONEOK/SafetyDocs/Natural%20Gas%20Condensate%20Petroleum.ashx
3.^"Hydrogen Sulfide," Occupational Safety and Health Administration, Fact Sheet, 2005, http://www.osha.gov/OshDoc/data_Hurricane_Facts/hydrogen_sulfide_fact.pdf, "Material Safety Data Sheet: DilBit Cold Lake Blend," Imperial Oil, 2002, http://www.msdsxchange.com/english/show_msds.cfm?paramid1=2479752
4.^"Material Safety Data Sheet: DilBit Cold Lake Blend," Imperial Oil, 2002, http://www.msdsxchange.com/english/show_msds.cfm?paramid1=2479752
5.^Toxicological Profile for Polycyclic Aromatic Hydrocarbons, Agency for Toxic Substances and Disease Registry, 1995, http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=122&tid=25. Benzene, Agency for Toxic Substances and Disease Registry, 1995, http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=14
6.^"Athabasca Bitumen," Environment Canada, Emergencies Science and Technology Division, http://www.etc-cte.ec.gc.ca/databases/OilProperties/pdf/WEB_Athabasca_Bitumen.pdf
7.^The bioaccumulation of heavy metals is well established in academic literature (see, for example, R. Vinodhini and M. Narayanan, Bioaccumulation of heavy metals in organs of freshwater fish Cyprinus carpio (Common carp), Int. J. Environ. Sci. Tech, 5 (2), Spring 2008, 179-182, http://www.ceers.org/ijest/issues/full/v5/n2/502005.pdf, Heavy metals are elemental in nature and cannot biodegrade and have a variety of toxic effects ("Toxicological Profiles," Agency for Toxic Substances and Disease Registry, 2010, http://www.atsdr.cdc.gov/toxprofiles/index.asp