From the National Energy Board we can find out what is in Dilbit and what precautions we need when it lands on the shores of Metchosin.
You can see the original in this link : or as copied in the images below:

https://docs.neb-one.gc.ca/ll-eng/llisapi.dll/fetch/2000/90464/90552/548311/956726/2392873/2450810/2478758/2522888/Material_Safety_Data_Sheet_-_Diluted_Bitumen_-_A4A9D1.pdf?nodeid=2508614&vernum=-2

ALSO: The following link gives the Occupational and Health Guidelines for Benzene, a Potential Human Carcinogen

https://docs.neb-one.gc.ca/ll-eng/llisapi.dll/fetch/2000/90464/90552/548311/956726/2392873/2450810/2478758/2522888/Occupational_Safety_and_Health_Guideline_for_Benzene_-_A4A9D2.pdf?nodeid=2504533&vernum=-2