Dirty socks are usually the packs, not toxins.

It is likely and common for at least a little oil to contaminate the bleeds...largely mitigated by closing bleeds before shutdown and not using bleeds during engine start...these are universal procedures and most new airplanes will auto-configure the bleeds even if you forget. But the good news about modern airplane oil is that it uses TCP that is formulated differently and is far less toxic than decades ago. There is a also a new low-toxicity TCP which should be unable to produce the neuro-toxic compounds due to lack of certain pre-cursors. I'd be interested in knowing if any airlines use the "low-tox" oil, although I'm satisfied that modern oil is very, very low risk anyway.

Hyd Oil is probably the bogey-man here. Since fluid change intervals are much longer in Hyd systems, I assume Hyd fluids have a higher concentration of consumable anti-wear additives (normal engineering practice), so a malfunction which were to dump Hyd fluid into bleeds might result in much more TCP combustion products entering the cabin. I don't what type of TCP is used in Hyd fluid, but I suspect this is the scenario to lose sleep over. Good news here is that, unlike Eng oil, Hyd oil should never enter the bleeds unless there's a big malfunction.

Part of our problem is that airlines are exempt from OSHA oversight, and the FAA seems to do a very poor job of filling their shoes. FAA is pretty good at preventing crashes, but they don't seem to care much about OSHA-type issues.

Some people are naturally pre-disposed to vulnerability to chemical toxins...I know a young pilot who has had skin cancer, and every male member of his family has died of cancer before age 50. His docs told him never to fuel his own car, change his own oil, use a lawnmower, or even open the hood of his car. This is a guy who needs to worry, and should probably find a new career (organic farmer?).

It would be nice if we had more info on exactly what type and how much TCPs are in the fluids on our aircraft...this would be a reasonable first step for the unions to shoot for IMO. I think that certain levels of the newest TCP compounds are probably safe enough for most of us...we'd just like to know what we're dealing with.