We do not use any prop 65 ingredients in our chemicals. If you do then a warning should be on the product label as well as the SDS. California's list is the most extensive in terms of potential carcinogens. However, when California puts coffee on the prop 65 list, then it loses a lot of credibility, but generally I agree with their listing of cleaning raw materials.
The SDS only requires the listing of the ingredients, which cause the greatest danger in any particular area of hazard: eyes, skin, breathing, ingestion, fire, etc. Sodium Metasilicate, for example, irritates skin and eyes more than sodium carbonate so only the sodium metasilicate would need to be listed. Some solvents create a low flash point while others do not requiring only the one most volatile solvent to be listed. Even though you may have 10 ingredients in the formula it often happens that one or two ingredients are the most significant reasons for all of hazards. In an emergency situation it is better for a doctor to be able to quickly isolate the greatest hazards rather than looking up each individual ingredient.
Remember that the SDS defines the hazard in the bottle. We have provided for many of our products a ready to use SDS which reflects any hazards that the cleaner or consumer are actually exposed to in the course of cleaning. One adage that I have heard often is that "the solution to the pollution is dilution." Arsenic is in a lot of our water supplies, but its presence has been highly diluted.